podman-create(1) General Commands Manual podman-create(1)
NAME
podman-create - Create a new container
SYNOPSIS
podman create [options] image [command [arg ...]]
podman container create [options] image [command [arg ...]]
DESCRIPTION
Creates a writable container layer over the specified image and prepares
it for running the specified command. The container ID is then printed
to STDOUT. This is similar to podman run -d except the container is
never started. Use the podman start container command to start the con-
tainer at any point.
The initial status of the container created with podman create is 'cre-
ated'.
Default settings for flags are defined in containers.conf. Most settings
for remote connections use the server's containers.conf, except when
documented in man pages.
IMAGE
The image is specified using transport:path format. If no transport is
specified, the docker (container registry) transport is used by default.
For remote Podman, including Mac and Windows (excluding WSL2) machines,
docker is the only allowed transport.
dir:path
An existing local directory path storing the manifest, layer tarballs
and signatures as individual files. This is a non-standardized format,
primarily useful for debugging or noninvasive container inspection.
$ podman save --format docker-dir fedora -o /tmp/fedora
$ podman create dir:/tmp/fedora echo hello
docker://docker-reference (Default)
An image reference stored in a remote container image registry. Exam-
ple: "quay.io/podman/stable:latest". The reference can include a path
to a specific registry; if it does not, the registries listed in reg-
istries.conf is queried to find a matching image. By default, creden-
tials from podman login (stored at $XDG_RUNTIME_DIR/containers/auth.json
by default) is used to authenticate; otherwise it falls back to using
credentials in $HOME/.docker/config.json.
$ podman create registry.fedoraproject.org/fedora:latest echo hello
docker-archive:path[:docker-reference] An image stored in the docker
save formatted file. docker-reference is only used when creating such a
file, and it must not contain a digest.
$ podman save --format docker-archive fedora -o /tmp/fedora
$ podman create docker-archive:/tmp/fedora echo hello
docker-daemon:docker-reference
An image in docker-reference format stored in the docker daemon inter-
nal storage. The docker-reference can also be an image ID (docker-dae-
mon:algo:digest).
$ sudo docker pull fedora
$ sudo podman create docker-daemon:docker.io/library/fedora echo hello
oci-archive:path:tag
An image in a directory compliant with the "Open Container Image Lay-
out Specification" at the specified path and specified with a tag.
$ podman save --format oci-archive fedora -o /tmp/fedora
$ podman create oci-archive:/tmp/fedora echo hello
OPTIONS
--add-host=hostname[;hostname[;...]]:ip
Add a custom host-to-IP mapping to the container's /etc/hosts file.
The option takes one or multiple semicolon-separated hostnames to be
mapped to a single IPv4 or IPv6 address, separated by a colon. It can
also be used to overwrite the IP addresses of hostnames Podman adds to
/etc/hosts by default (also see the --name and --hostname options). This
option can be specified multiple times to add additional mappings to
/etc/hosts. It conflicts with the --no-hosts option and conflicts with
no_hosts=true in containers.conf.
Instead of an IP address, the special flag host-gateway can be given.
This resolves to an IP address the container can use to connect to the
host. The IP address chosen depends on your network setup, thus there's
no guarantee that Podman can determine the host-gateway address automat-
ically, which will then cause Podman to fail with an error message. You
can overwrite this IP address using the host_containers_internal_ip op-
tion in containers.conf.
The host-gateway address is also used by Podman to automatically add the
host.containers.internal and host.docker.internal hostnames to
/etc/hosts. You can prevent that by either giving the --no-hosts op-
tion, or by setting host_containers_internal_ip="none" in contain-
ers.conf. If no host-gateway address was configured manually and Podman
fails to determine the IP address automatically, Podman will silently
skip adding these internal hostnames to /etc/hosts. If Podman is running
in a virtual machine using podman machine (this includes Mac and Windows
hosts), Podman will silently skip adding the internal hostnames to
/etc/hosts, unless an IP address was configured manually; the internal
hostnames are resolved by the gvproxy DNS resolver instead.
Podman will use the /etc/hosts file of the host as a basis by default,
i.e. any hostname present in this file will also be present in the
/etc/hosts file of the container. A different base file can be config-
ured using the base_hosts_file config in containers.conf.
--annotation=key=value
Add an annotation to the container. This option can be set multiple
times.
--arch=ARCH
Override the architecture, defaults to hosts, of the image to be pulled.
For example, arm. Unless overridden, subsequent lookups of the same im-
age in the local storage matches this architecture, regardless of the
host.
--attach, -a=stdin | stdout | stderr
Attach to STDIN, STDOUT or STDERR.
In foreground mode (the default when -d is not specified), podman run
can start the process in the container and attach the console to the
process's standard input, output, and error. It can even pretend to be a
TTY (this is what most command-line executables expect) and pass along
signals. The -a option can be set for each of stdin, stdout, and stderr.
--authfile=path
Path of the authentication file. Default is ${XDG_RUNTIME_DIR}/contain-
ers/auth.json on Linux, and $HOME/.config/containers/auth.json on Win-
dows/macOS. The file is created by podman login. If the authorization
state is not found there, $HOME/.docker/config.json is checked, which is
set using docker login.
Note: There is also the option to override the default path of the au-
thentication file by setting the REGISTRY_AUTH_FILE environment vari-
able. This can be done with export REGISTRY_AUTH_FILE=path.
--blkio-weight=weight
Block IO relative weight. The weight is a value between 10 and 1000.
This option is not supported on cgroups V1 rootless systems.
--blkio-weight-device=device:weight
Block IO relative device weight.
--cap-add=capability
Add Linux capabilities.
--cap-drop=capability
Drop Linux capabilities.
--cgroup-conf=KEY=VALUE
When running on cgroup v2, specify the cgroup file to write to and its
value. For example --cgroup-conf=memory.high=1073741824 sets the mem-
ory.high limit to 1GB.
--cgroup-parent=path
Path to cgroups under which the cgroup for the container is created. If
the path is not absolute, the path is considered to be relative to the
cgroups path of the init process. Cgroups are created if they do not al-
ready exist.
--cgroupns=mode
Set the cgroup namespace mode for the container.
• host: use the host's cgroup namespace inside the container.
• container:id: join the namespace of the specified container.
• private: create a new cgroup namespace.
• ns:path: join the namespace at the specified path.
If the host uses cgroups v1, the default is set to host. On cgroups v2,
the default is private.
--cgroups=how
Determines whether the container creates CGroups.
Default is enabled.
The enabled option creates a new cgroup under the cgroup-parent. The
disabled option forces the container to not create CGroups, and thus
conflicts with CGroup options (--cgroupns and --cgroup-parent). The no-
conmon option disables a new CGroup only for the conmon process. The
split option splits the current CGroup in two sub-cgroups: one for con-
mon and one for the container payload. It is not possible to set
--cgroup-parent with split.
--chrootdirs=path
Path to a directory inside the container that is treated as a chroot di-
rectory. Any Podman managed file (e.g., /etc/resolv.conf, /etc/hosts,
etc/hostname) that is mounted into the root directory is mounted into
that location as well. Multiple directories are separated with a comma.
--cidfile=file
Write the container ID to file. The file is removed along with the con-
tainer, except when used with podman --remote run on detached contain-
ers.
--conmon-pidfile=file
Write the pid of the conmon process to a file. As conmon runs in a sepa-
rate process than Podman, this is necessary when using systemd to
restart Podman containers. (This option is not available with the re-
mote Podman client, including Mac and Windows (excluding WSL2) machines)
--cpu-period=limit
Set the CPU period for the Completely Fair Scheduler (CFS), which is a
duration in microseconds. Once the container's CPU quota is used up, it
will not be scheduled to run until the current period ends. Defaults to
100000 microseconds.
On some systems, changing the resource limits may not be allowed for
non-root users. For more details, see https://github.com/containers/pod-
man/blob/main/troubleshooting.md#26-running-containers-with-resource-
limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--cpu-quota=limit
Limit the CPU Completely Fair Scheduler (CFS) quota.
Limit the container's CPU usage. By default, containers run with the
full CPU resource. The limit is a number in microseconds. If a number is
provided, the container is allowed to use that much CPU time until the
CPU period ends (controllable via --cpu-period).
On some systems, changing the resource limits may not be allowed for
non-root users. For more details, see https://github.com/containers/pod-
man/blob/main/troubleshooting.md#26-running-containers-with-resource-
limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--cpu-rt-period=microseconds
Limit the CPU real-time period in microseconds.
Limit the container's Real Time CPU usage. This option tells the kernel
to restrict the container's Real Time CPU usage to the period specified.
This option is only supported on cgroups V1 rootful systems.
--cpu-rt-runtime=microseconds
Limit the CPU real-time runtime in microseconds.
Limit the containers Real Time CPU usage. This option tells the kernel
to limit the amount of time in a given CPU period Real Time tasks may
consume. Ex: Period of 1,000,000us and Runtime of 950,000us means that
this container can consume 95% of available CPU and leave the remaining
5% to normal priority tasks.
The sum of all runtimes across containers cannot exceed the amount al-
lotted to the parent cgroup.
This option is only supported on cgroups V1 rootful systems.
--cpu-shares, -c=shares
CPU shares (relative weight).
By default, all containers get the same proportion of CPU cycles. This
proportion can be modified by changing the container's CPU share weight-
ing relative to the combined weight of all the running containers. De-
fault weight is 1024.
The proportion only applies when CPU-intensive processes are running.
When tasks in one container are idle, other containers can use the left-
over CPU time. The actual amount of CPU time varies depending on the
number of containers running on the system.
For example, consider three containers, one has a cpu-share of 1024 and
two others have a cpu-share setting of 512. When processes in all three
containers attempt to use 100% of CPU, the first container receives 50%
of the total CPU time. If a fourth container is added with a cpu-share
of 1024, the first container only gets 33% of the CPU. The remaining
containers receive 16.5%, 16.5% and 33% of the CPU.
On a multi-core system, the shares of CPU time are distributed over all
CPU cores. Even if a container is limited to less than 100% of CPU time,
it can use 100% of each individual CPU core.
For example, consider a system with more than three cores. If the con-
tainer C0 is started with --cpu-shares=512 running one process, and an-
other container C1 with --cpu-shares=1024 running two processes, this
can result in the following division of CPU shares:
┌─────┬───────────┬─────┬──────────────┐
│ PID │ container │ CPU │ CPU share │
├─────┼───────────┼─────┼──────────────┤
│ 100 │ C0 │ 0 │ 100% of CPU0 │
├─────┼───────────┼─────┼──────────────┤
│ 101 │ C1 │ 1 │ 100% of CPU1 │
├─────┼───────────┼─────┼──────────────┤
│ 102 │ C1 │ 2 │ 100% of CPU2 │
└─────┴───────────┴─────┴──────────────┘
On some systems, changing the resource limits may not be allowed for
non-root users. For more details, see https://github.com/containers/pod-
man/blob/main/troubleshooting.md#26-running-containers-with-resource-
limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--cpus=number
Number of CPUs. The default is 0.0 which means no limit. This is short-
hand for --cpu-period and --cpu-quota, therefore the option cannot be
specified with --cpu-period or --cpu-quota.
On some systems, changing the CPU limits may not be allowed for non-root
users. For more details, see https://github.com/containers/pod-
man/blob/main/troubleshooting.md#26-running-containers-with-resource-
limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--cpuset-cpus=number
CPUs in which to allow execution. Can be specified as a comma-separated
list (e.g. 0,1), as a range (e.g. 0-3), or any combination thereof (e.g.
0-3,7,11-15).
On some systems, changing the resource limits may not be allowed for
non-root users. For more details, see https://github.com/containers/pod-
man/blob/main/troubleshooting.md#26-running-containers-with-resource-
limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--cpuset-mems=nodes
Memory nodes (MEMs) in which to allow execution (0-3, 0,1). Only effec-
tive on NUMA systems.
If there are four memory nodes on the system (0-3), use --cpuset-
mems=0,1 then processes in the container only uses memory from the first
two memory nodes.
On some systems, changing the resource limits may not be allowed for
non-root users. For more details, see https://github.com/containers/pod-
man/blob/main/troubleshooting.md#26-running-containers-with-resource-
limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--decryption-key=key[:passphrase]
The [key[:passphrase]] to be used for decryption of images. Key can
point to keys and/or certificates. Decryption is tried with all keys. If
the key is protected by a passphrase, it is required to be passed in the
argument and omitted otherwise.
--device=host-device[:container-device][:permissions]
Add a host device to the container. Optional permissions parameter can
be used to specify device permissions by combining r for read, w for
write, and m for mknod(2).
Example: --device=/dev/sdc:/dev/xvdc:rwm.
Note: if host-device is a symbolic link then it is resolved first. The
container only stores the major and minor numbers of the host device.
Podman may load kernel modules required for using the specified device.
The devices that Podman loads modules for when necessary are: /dev/fuse.
In rootless mode, the new device is bind mounted in the container from
the host rather than Podman creating it within the container space. Be-
cause the bind mount retains its SELinux label on SELinux systems, the
container can get permission denied when accessing the mounted device.
Modify SELinux settings to allow containers to use all device labels via
the following command:
$ sudo setsebool -P container_use_devices=true
Note: if the user only has access rights via a group, accessing the de-
vice from inside a rootless container fails. Use the --group-add keep-
groups flag to pass the user's supplementary group access into the con-
tainer.
--device-cgroup-rule="type major:minor mode"
Add a rule to the cgroup allowed devices list. The rule is expected to
be in the format specified in the Linux kernel documentation admin-
guide/cgroup-v1/devices: - type: a (all), c (char), or b (block); - ma-
jor and minor: either a number, or * for all; - mode: a composition of r
(read), w (write), and m (mknod(2)).
--device-read-bps=path:rate
Limit read rate (in bytes per second) from a device (e.g. --device-read-
bps=/dev/sda:1mb).
On some systems, changing the resource limits may not be allowed for
non-root users. For more details, see https://github.com/containers/pod-
man/blob/main/troubleshooting.md#26-running-containers-with-resource-
limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--device-read-iops=path:rate
Limit read rate (in IO operations per second) from a device (e.g. --de-
vice-read-iops=/dev/sda:1000).
On some systems, changing the resource limits may not be allowed for
non-root users. For more details, see https://github.com/containers/pod-
man/blob/main/troubleshooting.md#26-running-containers-with-resource-
limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--device-write-bps=path:rate
Limit write rate (in bytes per second) to a device (e.g. --device-write-
bps=/dev/sda:1mb).
On some systems, changing the resource limits may not be allowed for
non-root users. For more details, see https://github.com/containers/pod-
man/blob/main/troubleshooting.md#26-running-containers-with-resource-
limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--device-write-iops=path:rate
Limit write rate (in IO operations per second) to a device (e.g. --de-
vice-write-iops=/dev/sda:1000).
On some systems, changing the resource limits may not be allowed for
non-root users. For more details, see https://github.com/containers/pod-
man/blob/main/troubleshooting.md#26-running-containers-with-resource-
limits-fails-with-a-permissions-error
This option is not supported on cgroups V1 rootless systems.
--disable-content-trust
This is a Docker-specific option to disable image verification to a con-
tainer registry and is not supported by Podman. This option is a NOOP
and provided solely for scripting compatibility.
--dns=ipaddr
Set custom DNS servers.
This option can be used to override the DNS configuration passed to the
container. Typically this is necessary when the host DNS configuration
is invalid for the container (e.g., 127.0.0.1). When this is the case
the --dns flag is necessary for every run.
The special value none can be specified to disable creation of /etc/re-
solv.conf in the container by Podman. The /etc/resolv.conf file in the
image is used without changes.
This option cannot be combined with --network that is set to none or
container:id.
--dns-option=option
Set custom DNS options. Invalid if using --dns-option with --network
that is set to none or container:id.
--dns-search=domain
Set custom DNS search domains. Invalid if using --dns-search with --net-
work that is set to none or container:id. Use --dns-search=. to remove
the search domain.
--entrypoint="command" | '["command", arg1 , ...]'
Override the default ENTRYPOINT from the image.
The ENTRYPOINT of an image is similar to a COMMAND because it specifies
what executable to run when the container starts, but it is (purposely)
more difficult to override. The ENTRYPOINT gives a container its default
nature or behavior. When the ENTRYPOINT is set, the container runs as if
it were that binary, complete with default options. More options can be
passed in via the COMMAND. But, if a user wants to run something else
inside the container, the --entrypoint option allows a new ENTRYPOINT to
be specified.
Specify multi option commands in the form of a json string.
--env, -e=env
Set environment variables.
This option allows arbitrary environment variables that are available
for the process to be launched inside of the container. If an environ-
ment variable is specified without a value, Podman checks the host envi-
ronment for a value and set the variable only if it is set on the host.
As a special case, if an environment variable ending in * is specified
without a value, Podman searches the host environment for variables
starting with the prefix and adds those variables to the container.
See ⟨#environment⟩ note below for precedence and examples.
--env-file=file
Read in a line-delimited file of environment variables.
See ⟨#environment⟩ note below for precedence and examples.
--env-host
Use host environment inside of the container. See Environment note below
for precedence. (This option is not available with the remote Podman
client, including Mac and Windows (excluding WSL2) machines)
--env-merge=env
Preprocess default environment variables for the containers. For example
if image contains environment variable hello=world user can preprocess
it using --env-merge hello=${hello}-some so new value is hello=world-
some.
Please note that if the environment variable hello is not present in the
image, then it'll be replaced by an empty string and so using --env-
merge hello=${hello}-some would result in the new value of hello=-some,
notice the leading - delimiter.
--expose=port[/protocol]
Expose a port or a range of ports (e.g. --expose=3300-3310). The proto-
col can be tcp, udp or sctp and if not given tcp is assumed. This op-
tion matches the EXPOSE instruction for image builds and has no effect
on the actual networking rules unless -P/--publish-all is used to for-
ward to all exposed ports from random host ports. To forward specific
ports from the host into the container use the -p/--publish option in-
stead.
--gidmap=[flags]container_uid:from_uid[:amount]
Run the container in a new user namespace using the supplied GID map-
ping. This option conflicts with the --userns and --subgidname options.
This option provides a way to map host GIDs to container GIDs in the
same way as --uidmap maps host UIDs to container UIDs. For details see
--uidmap.
Note: the --gidmap option cannot be called in conjunction with the --pod
option as a gidmap cannot be set on the container level when in a pod.
--gpus=ENTRY
GPU devices to add to the container ('all' to pass all GPUs) Currently
only Nvidia devices are supported.
--group-add=group | keep-groups
Assign additional groups to the primary user running within the con-
tainer process.
• keep-groups is a special flag that tells Podman to keep the
supplementary group access.
Allows container to use the user's supplementary group access. If file
systems or devices are only accessible by the rootless user's group,
this flag tells the OCI runtime to pass the group access into the con-
tainer. Currently only available with the crun OCI runtime. Note: keep-
groups is exclusive, other groups cannot be specified with this flag.
(Not available for remote commands, including Mac and Windows (excluding
WSL2) machines)
--group-entry=ENTRY
Customize the entry that is written to the /etc/group file within the
container when --user is used.
The variables $GROUPNAME, $GID, and $USERLIST are automatically replaced
with their value at runtime if present.
--health-cmd="command" | '["command", arg1 , ...]'
Set or alter a healthcheck command for a container. The command is a
command to be executed inside the container that determines the con-
tainer health. The command is required for other healthcheck options to
be applied. A value of none disables existing healthchecks.
Multiple options can be passed in the form of a JSON array; otherwise,
the command is interpreted as an argument to /bin/sh -c.
--health-interval=interval
Set an interval for the healthchecks. An interval of disable results in
no automatic timer setup. The default is 30s.
--health-log-destination=directory_path
Set the destination of the HealthCheck log. Directory path, local or
events_logger (local use container state file) (Default: local)
• local: (default) HealthCheck logs are stored in overlay con-
tainers. (For example: $runroot/healthcheck.log)
• directory: creates a log file named <container-
ID>-healthcheck.log with HealthCheck logs in the specified di-
rectory.
• events_logger: The log will be written with logging mechanism
set by events_logger. It also saves the log to a default direc-
tory, for performance on a system with a large number of logs.
--health-max-log-count=number of stored logs
Set maximum number of attempts in the HealthCheck log file. ('0' value
means an infinite number of attempts in the log file) (Default: 5 at-
tempts)
--health-max-log-size=size of stored logs
Set maximum length in characters of stored HealthCheck log. ("0" value
means an infinite log length) (Default: 500 characters)
--health-on-failure=action
Action to take once the container transitions to an unhealthy state.
The default is none.
• none: Take no action.
• kill: Kill the container.
• restart: Restart the container. Do not combine the restart ac-
tion with the --restart flag. When running inside of a systemd
unit, consider using the kill or stop action instead to make
use of systemd's restart policy.
• stop: Stop the container.
--health-retries=retries
The number of retries allowed before a healthcheck is considered to be
unhealthy. The default value is 3.
--health-start-period=period
The initialization time needed for a container to bootstrap. The value
can be expressed in time format like 2m3s. The default value is 0s.
Note: The health check command is executed as soon as a container is
started, if the health check is successful the container's health state
will be updated to healthy. However, if the health check fails, the
health state will stay as starting until either the health check is suc-
cessful or until the --health-start-period time is over. If the health
check command fails after the --health-start-period time is over, the
health state will be updated to unhealthy. The health check command is
executed periodically based on the value of --health-interval.
--health-startup-cmd="command" | '["command", arg1 , ...]'
Set a startup healthcheck command for a container. This command is exe-
cuted inside the container and is used to gate the regular healthcheck.
When the startup command succeeds, the regular healthcheck begins and
the startup healthcheck ceases. Optionally, if the command fails for a
set number of attempts, the container is restarted. A startup
healthcheck can be used to ensure that containers with an extended
startup period are not marked as unhealthy until they are fully started.
Startup healthchecks can only be used when a regular healthcheck (from
the container's image or the --health-cmd option) is also set.
--health-startup-interval=interval
Set an interval for the startup healthcheck. An interval of disable re-
sults in no automatic timer setup. The default is 30s.
--health-startup-retries=retries
The number of attempts allowed before the startup healthcheck restarts
the container. If set to 0, the container is never restarted. The de-
fault is 0.
--health-startup-success=retries
The number of successful runs required before the startup healthcheck
succeeds and the regular healthcheck begins. A value of 0 means that any
success begins the regular healthcheck. The default is 0.
--health-startup-timeout=timeout
The maximum time a startup healthcheck command has to complete before it
is marked as failed. The value can be expressed in a time format like
2m3s. The default value is 30s.
--health-timeout=timeout
The maximum time allowed to complete the healthcheck before an interval
is considered failed. Like start-period, the value can be expressed in a
time format such as 1m22s. The default value is 30s.
--help
Print usage statement
--hostname, -h=name
Set the container's hostname inside the container.
This option can only be used with a private UTS namespace --uts=private
(default). If --pod is given and the pod shares the same UTS namespace
(default), the pod's hostname is used. The given hostname is also added
to the /etc/hosts file using the container's primary IP address (also
see the --add-host option).
--hosts-file=path | none | image
Base file to create the /etc/hosts file inside the container. This must
either be an absolute path to a file on the host system, or one of the
following special flags:
"" Follow the base_hosts_file configuration in containers.conf
(the default)
none Do not use a base file (i.e. start with an empty file)
image Use the container image's /etc/hosts file as base file
--hostuser=name
Add a user account to /etc/passwd from the host to the container. The
Username or UID must exist on the host system.
--http-proxy
By default proxy environment variables are passed into the container if
set for the Podman process. This can be disabled by setting the value to
false. The environment variables passed in include http_proxy,
https_proxy, ftp_proxy, no_proxy, and also the upper case versions of
those. This option is only needed when the host system must use a proxy
but the container does not use any proxy. Proxy environment variables
specified for the container in any other way overrides the values that
have been passed through from the host. (Other ways to specify the proxy
for the container include passing the values with the --env flag, or
hard coding the proxy environment at container build time.) When used
with the remote client it uses the proxy environment variables that are
set on the server process.
Defaults to true.
--image-volume=bind | tmpfs | ignore
Tells Podman how to handle the builtin image volumes. Default is bind.
• bind: An anonymous named volume is created and mounted into the
container.
• tmpfs: The volume is mounted onto the container as a tmpfs,
which allows the users to create content that disappears when
the container is stopped.
• ignore: All volumes are just ignored and no action is taken.
--init
Run an init inside the container that forwards signals and reaps
processes. The container-init binary is mounted at /run/podman-init.
Mounting over /run breaks container execution.
--init-ctr=type
(Pods only). When using pods, create an init style container, which is
run after the infra container is started but before regular pod contain-
ers are started. Init containers are useful for running setup opera-
tions for the pod's applications.
Valid values for init-ctr type are always or once. The always value
means the container runs with each and every pod start, whereas the once
value means the container only runs once when the pod is started and
then the container is removed.
Init containers are only run on pod start. Restarting a pod does not
execute any init containers. Furthermore, init containers can only be
created in a pod when that pod is not running.
--init-path=path
Path to the container-init binary.
--interactive, -i
When set to true, make stdin available to the contained process. If
false, the stdin of the contained process is empty and immediately
closed.
If attached, stdin is piped to the contained process. If detached, read-
ing stdin will block until later attached.
Caveat: Podman will consume input from stdin as soon as it becomes
available, even if the contained process doesn't request it.
--ip=ipv4
Specify a static IPv4 address for the container, for example
10.88.64.128. This option can only be used if the container is joined
to only a single network - i.e., --network=network-name is used at most
once - and if the container is not joining another container's network
namespace via --network=container:id. The address must be within the
network's IP address pool (default 10.88.0.0/16).
To specify multiple static IP addresses per container, set multiple net-
works using the --network option with a static IP address specified for
each using the ip mode for that option.
--ip6=ipv6
Specify a static IPv6 address for the container, for example
fd46:db93:aa76:ac37::10. This option can only be used if the container
is joined to only a single network - i.e., --network=network-name is
used at most once - and if the container is not joining another con-
tainer's network namespace via --network=container:id. The address must
be within the network's IPv6 address pool.
To specify multiple static IPv6 addresses per container, set multiple
networks using the --network option with a static IPv6 address specified
for each using the ip6 mode for that option.
--ipc=ipc
Set the IPC namespace mode for a container. The default is to create a
private IPC namespace.
• "": Use Podman's default, defined in containers.conf.
• container:id: reuses another container's shared memory, sema-
phores, and message queues
• host: use the host's shared memory, semaphores, and message
queues inside the container. Note: the host mode gives the con-
tainer full access to local shared memory and is therefore con-
sidered insecure.
• none: private IPC namespace, with /dev/shm not mounted.
• ns:path: path to an IPC namespace to join.
• private: private IPC namespace.
• shareable: private IPC namespace with a possibility to share it
with other containers.
--label, -l=key=value
Add metadata to a container.
--label-file=file
Read in a line-delimited file of labels.
--link-local-ip=ip
Not implemented.
--log-driver=driver
Logging driver for the container. Currently available options are k8s-
file, journald, none, passthrough and passthrough-tty, with json-file
aliased to k8s-file for scripting compatibility. (Default journald).
The podman info command below displays the default log-driver for the
system.
$ podman info --format '{{ .Host.LogDriver }}'
journald
The passthrough driver passes down the standard streams (stdin, stdout,
stderr) to the container. It is not allowed with the remote Podman
client, including Mac and Windows (excluding WSL2) machines, and on a
tty, since it is vulnerable to attacks via TIOCSTI.
The passthrough-tty driver is the same as passthrough except that it
also allows it to be used on a TTY if the user really wants it.
--log-opt=name=value
Logging driver specific options.
Set custom logging configuration. The following *name*s are supported:
path: specify a path to the log file
(e.g. --log-opt path=/var/log/container/mycontainer.json);
max-size: specify a max size of the log file
(e.g. --log-opt max-size=10mb);
tag: specify a custom log tag for the container
(e.g. --log-opt tag="{{.ImageName}}". It supports the same keys as
podman inspect --format. This option is currently supported only by the
journald log driver.
--mac-address=address
Container network interface MAC address (e.g. 92:d0:c6:0a:29:33) This
option can only be used if the container is joined to only a single net-
work - i.e., --network=network-name is used at most once - and if the
container is not joining another container's network namespace via
--network=container:id.
Remember that the MAC address in an Ethernet network must be unique.
The IPv6 link-local address is based on the device's MAC address accord-
ing to RFC4862.
To specify multiple static MAC addresses per container, set multiple
networks using the --network option with a static MAC address specified
for each using the mac mode for that option.
--memory, -m=number[unit]
Memory limit. A unit can be b (bytes), k (kibibytes), m (mebibytes), or
g (gibibytes).
Allows the memory available to a container to be constrained. If the
host supports swap memory, then the -m memory setting can be larger than
physical RAM. If a limit of 0 is specified (not using -m), the con-
tainer's memory is not limited. The actual limit may be rounded up to a
multiple of the operating system's page size (the value is very large,
that's millions of trillions).
This option is not supported on cgroups V1 rootless systems.
--memory-reservation=number[unit]
Memory soft limit. A unit can be b (bytes), k (kibibytes), m
(mebibytes), or g (gibibytes).
After setting memory reservation, when the system detects memory con-
tention or low memory, containers are forced to restrict their consump-
tion to their reservation. So always set the value below --memory, oth-
erwise the hard limit takes precedence. By default, memory reservation
is the same as memory limit.
This option is not supported on cgroups V1 rootless systems.
--memory-swap=number[unit]
A limit value equal to memory plus swap. A unit can be b (bytes), k
(kibibytes), m (mebibytes), or g (gibibytes).
Must be used with the -m (--memory) flag. The argument value must be
larger than that of
-m (--memory) By default, it is set to double the value of --memory.
Set number to -1 to enable unlimited swap.
This option is not supported on cgroups V1 rootless systems.
--memory-swappiness=number
Tune a container's memory swappiness behavior. Accepts an integer be-
tween 0 and 100.
This flag is only supported on cgroups V1 rootful systems.
--mount=type=TYPE,TYPE-SPECIFIC-OPTION[,...]
Attach a filesystem mount to the container
Current supported mount TYPEs are bind, devpts, glob, image, ramfs,
tmpfs and volume.
Options common to all mount types:
• src, source: mount source spec for bind, glob, and volume.
Mandatory for bind and glob.
• dst, destination, target: mount destination spec.
When source globs are specified without the destination directory, the
files and directories are mounted with their complete path within the
container. When the destination is specified, the files and directories
matching the glob on the base file name on the destination directory are
mounted. The option type=glob,src=/foo*,destination=/tmp/bar tells con-
tainer engines to mount host files matching /foo* to the /tmp/bar/ di-
rectory in the container.
Options specific to type=volume:
• ro, readonly: true or false (default if unspecified: false).
• U, chown: true or false (default if unspecified: false). Recur-
sively change the owner and group of the source volume based on
the UID and GID of the container.
• idmap: If specified, create an idmapped mount to the target
user namespace in the container. The idmap option is only sup-
ported by Podman in rootful mode. The Linux kernel does not al-
low the use of idmaped file systems for unprivileged users.
The idmap option supports a custom mapping that can be differ-
ent than the user namespace used by the container. The mapping
can be specified after the idmap option like:
idmap=uids=0-1-10#10-11-10;gids=0-100-10. For each triplet,
the first value is the start of the backing file system IDs
that are mapped to the second value on the host. The length of
this mapping is given in the third value. Multiple ranges are
separated with #. If the specified mapping is prepended with a
'@' then the mapping is considered relative to the container
user namespace. The host ID for the mapping is changed to ac-
count for the relative position of the container user in the
container user namespace.
Options specific to type=image:
• rw, readwrite: true or false (default if unspecified: false).
• subpath: Mount only a specific path within the image, instead
of the whole image.
Options specific to bind and glob:
• ro, readonly: true or false (default if unspecified: false).
• bind-propagation: shared, slave, private, unbindable, rshared,
rslave, runbindable, or rprivate (default).[1] ⟨#Footnote1⟩ See
also mount(2).
• bind-nonrecursive: do not set up a recursive bind mount. By de-
fault it is recursive.
• relabel: shared, private.
• idmap: true or false (default if unspecified: false). If true,
create an idmapped mount to the target user namespace in the
container. The idmap option is only supported by Podman in
rootful mode.
• U, chown: true or false (default if unspecified: false). Recur-
sively change the owner and group of the source volume based on
the UID and GID of the container.
• no-dereference: do not dereference symlinks but copy the link
source into the mount destination.
Options specific to type=tmpfs and ramfs:
• ro, readonly: true or false (default if unspecified: false).
• tmpfs-size: Size of the tmpfs/ramfs mount, in bytes. Unlimited
by default in Linux.
• tmpfs-mode: Octal file mode of the tmpfs/ramfs (e.g. 700 or
0700.).
• tmpcopyup: Enable copyup from the image directory at the same
location to the tmpfs/ramfs. Used by default.
• notmpcopyup: Disable copying files from the image to the
tmpfs/ramfs.
• U, chown: true or false (default if unspecified: false). Recur-
sively change the owner and group of the source volume based on
the UID and GID of the container.
Options specific to type=devpts:
• uid: numeric UID of the file owner (default: 0).
• gid: numeric GID of the file owner (default: 0).
• mode: octal permission mask for the file (default: 600).
• max: maximum number of PTYs (default: 1048576).
Examples:
• type=bind,source=/path/on/host,destination=/path/in/container
• type=bind,src=/path/on/host,dst=/path/in/container,rela-
bel=shared
• type=bind,src=/path/on/host,dst=/path/in/container,rela-
bel=shared,U=true
• type=devpts,destination=/dev/pts
• type=glob,src=/usr/lib/libfoo*,destination=/usr/lib,ro=true
• type=image,source=fedora,destination=/fedora-image,rw=true
• type=ramfs,tmpfs-size=512M,destination=/path/in/container
• type=tmpfs,tmpfs-size=512M,destination=/path/in/container
• type=tmpfs,destination=/path/in/container,noswap
• type=volume,source=vol1,destination=/path/in/container,ro=true
--name=name
Assign a name to the container.
The operator can identify a container in three ways:
• UUID long identifier
(“f78375b1c487e03c9438c729345e54db9d20cfa2ac1fc3494b6eb60872e74778”);
• UUID short identifier (“f78375b1c487”);
• Name (“jonah”).
Podman generates a UUID for each container, and if no name is assigned
to the container using --name, Podman generates a random string name.
The name can be useful as a more human-friendly way to identify contain-
ers. This works for both background and foreground containers. The con-
tainer's name is also added to the /etc/hosts file using the container's
primary IP address (also see the --add-host option).
--network=mode, --net
Set the network mode for the container.
Valid mode values are:
• bridge[:OPTIONS,...]: Create a network stack on the default
bridge. This is the default for rootful containers. It is pos-
sible to specify these additional options:
• alias=name: Add network-scoped alias for the container.
• ip=IPv4: Specify a static IPv4 address for this container.
• ip6=IPv6: Specify a static IPv6 address for this container.
• mac=MAC: Specify a static MAC address for this container.
• interface_name=name: Specify a name for the created network
interface inside the container.
• host_interface_name=name: Specify a name for the created net-
work interface outside the container.
Any other options will be passed through to netavark without val-
idation. This can be useful to pass arguments to netavark plug-
ins.For example, to set a static ipv4 address and a static mac
address, use --network
bridge:ip=10.88.0.10,mac=44:33:22:11:00:99.
• <network name or ID>[:OPTIONS,...]: Connect to a user-defined
network; this is the network name or ID from a network created
by podman network create. It is possible to specify the same
options described under the bridge mode above. Use the --net-
work option multiple times to specify additional networks.
For backwards compatibility it is also possible to specify
comma-separated networks on the first --network argument, how-
ever this prevents you from using the options described under
the bridge section above.
• none: Create a network namespace for the container but do not
configure network interfaces for it, thus the container has no
network connectivity.
• container:id: Reuse another container's network stack.
• host: Do not create a network namespace, the container uses the
host's network. Note: The host mode gives the container full
access to local system services such as D-bus and is therefore
considered insecure.
• ns:path: Path to a network namespace to join.
• private: Create a new namespace for the container. This uses
the bridge mode for rootful containers and slirp4netns for
rootless ones.
• slirp4netns[:OPTIONS,...]: use slirp4netns(1) to create a user
network stack. It is possible to specify these additional op-
tions, they can also be set with network_cmd_options in con-
tainers.conf:
• allow_host_loopback=true|false: Allow slirp4netns to reach
the host loopback IP (default is 10.0.2.2 or the second IP
from slirp4netns cidr subnet when changed, see the cidr op-
tion below). The default is false.
• mtu=MTU: Specify the MTU to use for this network. (Default is
65520).
• cidr=CIDR: Specify ip range to use for this network. (Default
is 10.0.2.0/24).
• enable_ipv6=true|false: Enable IPv6. Default is true. (Re-
quired for outbound_addr6).
• outbound_addr=INTERFACE: Specify the outbound interface slirp
binds to (ipv4 traffic only).
• outbound_addr=IPv4: Specify the outbound ipv4 address slirp
binds to.
• outbound_addr6=INTERFACE: Specify the outbound interface
slirp binds to (ipv6 traffic only).
• outbound_addr6=IPv6: Specify the outbound ipv6 address slirp
binds to.
• port_handler=rootlesskit: Use rootlesskit for port forward-
ing. Default.
Note: Rootlesskit changes the source IP address of incoming
packets to an IP address in the container network namespace,
usually 10.0.2.100. If the application requires the real
source IP address, e.g. web server logs, use the slirp4netns
port handler. The rootlesskit port handler is also used for
rootless containers when connected to user-defined networks.
• port_handler=slirp4netns: Use the slirp4netns port forward-
ing, it is slower than rootlesskit but preserves the correct
source IP address. This port handler cannot be used for user-
defined networks.
• pasta[:OPTIONS,...]: use pasta(1) to create a user-mode net-
working stack.
This is the default for rootless containers and only supported
in rootless mode.
By default, IPv4 and IPv6 addresses and routes, as well as the
pod interface name, are copied from the host. If port forward-
ing isn't configured, ports are forwarded dynamically as ser-
vices are bound on either side (init namespace or container
namespace). Port forwarding preserves the original source IP
address. Options described in pasta(1) can be specified as
comma-separated arguments.
In terms of pasta(1) options, --config-net is given by default,
in order to configure networking when the container is started,
and --no-map-gw is also assumed by default, to avoid direct ac-
cess from container to host using the gateway address. The lat-
ter can be overridden by passing --map-gw in the pasta-specific
options (despite not being an actual pasta(1) option).
Also, -t none and -u none are passed if, respectively, no TCP
or UDP port forwarding from host to container is configured, to
disable automatic port forwarding based on bound ports. Simi-
larly, -T none and -U none are given to disable the same func-
tionality from container to host.
Some examples:
• pasta:--map-gw: Allow the container to directly reach the
host using the gateway address.
• pasta:--mtu,1500: Specify a 1500 bytes MTU for the tap inter-
face in the container.
• pasta:--ipv4-only,-a,10.0.2.0,-n,24,-g,10.0.2.2,--dns-for-
ward,10.0.2.3,-m,1500,--no-ndp,--no-dhcpv6,--no-dhcp, equiva-
lent to default slirp4netns(1) options: disable IPv6, assign
10.0.2.0/24 to the tap0 interface in the container, with
gateway 10.0.2.3, enable DNS forwarder reachable at 10.0.2.3,
set MTU to 1500 bytes, disable NDP, DHCPv6 and DHCP support.
• pasta:-I,tap0,--ipv4-only,-a,10.0.2.0,-n,24,-g,10.0.2.2,--dns-
forward,10.0.2.3,--no-ndp,--no-dhcpv6,--no-dhcp, equivalent
to default slirp4netns(1) options with Podman overrides: same
as above, but leave the MTU to 65520 bytes
• pasta:-t,auto,-u,auto,-T,auto,-U,auto: enable automatic port
forwarding based on observed bound ports from both host and
container sides
• pasta:-T,5201: enable forwarding of TCP port 5201 from con-
tainer to host, using the loopback interface instead of the
tap interface for improved performance
Invalid if using --dns, --dns-option, or --dns-search with --network set
to none or container:id.
If used together with --pod, the container does not join the pod's net-
work namespace.
--network-alias=alias
Add a network-scoped alias for the container, setting the alias for all
networks that the container joins. To set a name only for a specific
network, use the alias option as described under the --network option.
If the network has DNS enabled (podman network inspect -f {{.DNSEn-
abled}} <name>), these aliases can be used for name resolution on the
given network. This option can be specified multiple times. NOTE: When
using CNI a container only has access to aliases on the first network
that it joins. This limitation does not exist with netavark/aardvark-
dns.
--no-healthcheck
Disable any defined healthchecks for container.
--no-hostname
Do not create the /etc/hostname file in the containers.
By default, Podman manages the /etc/hostname file, adding the con-
tainer's own hostname. When the --no-hostname option is set, the im-
age's /etc/hostname will be preserved unmodified if it exists.
--no-hosts
Do not modify the /etc/hosts file in the container.
Podman assumes control over the container's /etc/hosts file by default
and adds entries for the container's name (see --name option) and host-
name (see --hostname option), the internal host.containers.internal and
host.docker.internal hosts, as well as any hostname added using the
--add-host option. Refer to the --add-host option for details. Passing
--no-hosts disables this, so that the image's /etc/hosts file is kept
unmodified. The same can be achieved globally by setting no_hosts=true
in containers.conf.
This option conflicts with --add-host.
--oom-kill-disable
Whether to disable OOM Killer for the container or not.
This flag is not supported on cgroups V2 systems.
--oom-score-adj=num
Tune the host's OOM preferences for containers (accepts values from
-1000 to 1000).
When running in rootless mode, the specified value can't be lower than
the oom_score_adj for the current process. In this case, the oom-score-
adj is clamped to the current process value.
--os=OS
Override the OS, defaults to hosts, of the image to be pulled. For exam-
ple, windows. Unless overridden, subsequent lookups of the same image
in the local storage matches this OS, regardless of the host.
--passwd-entry=ENTRY
Customize the entry that is written to the /etc/passwd file within the
container when --passwd is used.
The variables $USERNAME, $UID, $GID, $NAME, $HOME are automatically re-
placed with their value at runtime.
--personality=persona
Personality sets the execution domain via Linux personality(2).
--pid=mode
Set the PID namespace mode for the container. The default is to create
a private PID namespace for the container.
• container:id: join another container's PID namespace;
• host: use the host's PID namespace for the container. Note the
host mode gives the container full access to local PID and is
therefore considered insecure;
• ns:path: join the specified PID namespace;
• private: create a new namespace for the container (default).
--pidfile=path
When the pidfile location is specified, the container process' PID is
written to the pidfile. (This option is not available with the remote
Podman client, including Mac and Windows (excluding WSL2) machines) If
the pidfile option is not specified, the container process' PID is writ-
ten to /run/containers/storage/${storage-driver}-containers/$CID/user-
data/pidfile.
After the container is started, the location for the pidfile can be dis-
covered with the following podman inspect command:
$ podman inspect --format '{{ .PidFile }}' $CID
/run/containers/storage/${storage-driver}-containers/$CID/userdata/pidfile
--pids-limit=limit
Tune the container's pids limit. Set to -1 to have unlimited pids for
the container. The default is 2048 on systems that support "pids" cgroup
controller.
--platform=OS/ARCH
Specify the platform for selecting the image. (Conflicts with --arch
and --os) The --platform option can be used to override the current ar-
chitecture and operating system. Unless overridden, subsequent lookups
of the same image in the local storage matches this platform, regardless
of the host.
--pod=name
Run container in an existing pod. Podman makes the pod automatically if
the pod name is prefixed with new:. To make a pod with more granular
options, use the podman pod create command before creating a container.
When a container is run with a pod with an infra-container, the infra-
container is started first.
--pod-id-file=file
Run container in an existing pod and read the pod's ID from the speci-
fied file. When a container is run within a pod which has an infra-con-
tainer, the infra-container starts first.
--privileged
Give extended privileges to this container. The default is false.
By default, Podman containers are unprivileged (=false) and cannot, for
example, modify parts of the operating system. This is because by de-
fault a container is only allowed limited access to devices. A "privi-
leged" container is given the same access to devices as the user launch-
ing the container, with the exception of virtual consoles (/dev/tty\d+)
when running in systemd mode (--systemd=always).
A privileged container turns off the security features that isolate the
container from the host. Dropped Capabilities, limited devices, read-
only mount points, Apparmor/SELinux separation, and Seccomp filters are
all disabled. Due to the disabled security features, the privileged
field should almost never be set as containers can easily break out of
confinement.
Containers running in a user namespace (e.g., rootless containers) can-
not have more privileges than the user that launched them.
--publish, -p=[[ip:][hostPort]:]containerPort[/protocol]
Publish a container's port, or range of ports, to the host.
Both hostPort and containerPort can be specified as a range of ports.
When specifying ranges for both, the number of container ports in the
range must match the number of host ports in the range.
If host IP is set to 0.0.0.0 or not set at all, the port is bound on all
IPs on the host.
By default, Podman publishes TCP ports. To publish a UDP port instead,
give udp as protocol. To publish both TCP and UDP ports, set --publish
twice, with tcp, and udp as protocols respectively. Rootful containers
can also publish ports using the sctp protocol.
Host port does not have to be specified (e.g. podman run -p
127.0.0.1::80). If it is not, the container port is randomly assigned a
port on the host.
Use podman port to see the actual mapping: podman port $CONTAINER $CON-
TAINERPORT.
Note that the network drivers macvlan and ipvlan do not support port
forwarding, it will have no effect on these networks.
Note: If a container runs within a pod, it is not necessary to publish
the port for the containers in the pod. The port must only be published
by the pod itself. Pod network stacks act like the network stack on the
host - when there are a variety of containers in the pod, and programs
in the container, all sharing a single interface and IP address, and as-
sociated ports. If one container binds to a port, no other container can
use that port within the pod while it is in use. Containers in the pod
can also communicate over localhost by having one container bind to lo-
calhost in the pod, and another connect to that port.
--publish-all, -P
Publish all exposed ports to random ports on the host interfaces. The
default is false.
When set to true, publish all exposed ports to the host interfaces. If
the operator uses -P (or -p) then Podman makes the exposed port accessi-
ble on the host and the ports are available to any client that can reach
the host.
When using this option, Podman binds any exposed port to a random port
on the host within an ephemeral port range defined by
/proc/sys/net/ipv4/ip_local_port_range. To find the mapping between the
host ports and the exposed ports, use podman port.
--pull=policy
Pull image policy. The default is missing.
• always: Always pull the image and throw an error if the pull
fails.
• missing: Pull the image only when the image is not in the local
containers storage. Throw an error if no image is found and
the pull fails.
• never: Never pull the image but use the one from the local con-
tainers storage. Throw an error if no image is found.
• newer: Pull if the image on the registry is newer than the one
in the local containers storage. An image is considered to be
newer when the digests are different. Comparing the time
stamps is prone to errors. Pull errors are suppressed if a lo-
cal image was found.
--quiet, -q
Suppress output information when pulling images
--rdt-class=intel-rdt-class-of-service
Rdt-class sets the class of service (CLOS or COS) for the container to
run in. Based on the Cache Allocation Technology (CAT) feature that is
part of Intel's Resource Director Technology (RDT) feature set, all con-
tainer processes will run within the pre-configured COS, representing a
part of the cache. The COS has to be created and configured using a
pseudo file system (usually mounted at /sys/fs/resctrl) that the resctrl
kernel driver provides. Assigning the container to a COS requires root
privileges and thus doesn't work in a rootless environment. Currently,
the feature is only supported using runc as a runtime. See
⟨https://docs.kernel.org/arch/x86/resctrl.html⟩ for more details on cre-
ating a COS before a container can be assigned to it.
--read-only
Mount the container's root filesystem as read-only.
By default, container root filesystems are writable, allowing processes
to write files anywhere. By specifying the --read-only flag, the con-
tainers root filesystem are mounted read-only prohibiting any writes.
--read-only-tmpfs
When running --read-only containers, mount a read-write tmpfs on /dev,
/dev/shm, /run, /tmp, and /var/tmp. The default is true.
┌─────────────┬───────────────────┬─────┬──────────────────────┐
│ --read-only │ --read-only-tmpfs │ / │ /run, /tmp, /var/tmp │
├─────────────┼───────────────────┼─────┼──────────────────────┤
│ true │ true │ r/o │ r/w │
├─────────────┼───────────────────┼─────┼──────────────────────┤
│ true │ false │ r/o │ r/o │
├─────────────┼───────────────────┼─────┼──────────────────────┤
│ false │ false │ r/w │ r/w │
├─────────────┼───────────────────┼─────┼──────────────────────┤
│ false │ true │ r/w │ r/w │
└─────────────┴───────────────────┴─────┴──────────────────────┘
When --read-only=true and --read-only-tmpfs=true additional tmpfs are
mounted on the /tmp, /run, and /var/tmp directories.
When --read-only=true and --read-only-tmpfs=false /dev and /dev/shm are
marked Read/Only and no tmpfs are mounted on /tmp, /run and /var/tmp.
The directories are exposed from the underlying image, meaning they are
read-only by default. This makes the container totally read-only. No
writable directories exist within the container. In this mode writable
directories need to be added via external volumes or mounts.
By default, when --read-only=false, the /dev and /dev/shm are
read/write, and the /tmp, /run, and /var/tmp are read/write directories
from the container image.
--replace
If another container with the same name already exists, replace and re-
move it. The default is false.
--requires=container
Specify one or more requirements. A requirement is a dependency con-
tainer that is started before this container. Containers can be speci-
fied by name or ID, with multiple containers being separated by commas.
--restart=policy
Restart policy to follow when containers exit. Restart policy does not
take effect if a container is stopped via the podman kill or podman stop
commands.
Valid policy values are:
• no : Do not restart containers on exit
• never : Synonym for no; do not restart con-
tainers on exit
• on-failure[:max_retries] : Restart containers when they exit
with a non-zero exit code, retrying indefinitely or until the
optional max_retries count is hit
• always : Restart containers when they exit,
regardless of status, retrying indefinitely
• unless-stopped : Identical to always
Podman provides a systemd unit file, podman-restart.service, which
restarts containers after a system reboot.
When running containers in systemd services, use the restart functional-
ity provided by systemd. In other words, do not use this option in a
container unit, instead set the Restart= systemd directive in the [Ser-
vice] section. See podman-systemd.unit(5) and systemd.service(5).
--retry=attempts
Number of times to retry pulling or pushing images between the registry
and local storage in case of failure. Default is 3.
--retry-delay=duration
Duration of delay between retry attempts when pulling or pushing images
between the registry and local storage in case of failure. The default
is to start at two seconds and then exponentially back off. The delay is
used when this value is set, and no exponential back off occurs.
--rm
Automatically remove the container and any anonymous unnamed volume as-
sociated with the container when it exits. The default is false.
--rootfs
If specified, the first argument refers to an exploded container on the
file system.
This is useful to run a container without requiring any image manage-
ment, the rootfs of the container is assumed to be managed externally.
Overlay Rootfs Mounts
The :O flag tells Podman to mount the directory from the rootfs path as
storage using the overlay file system. The container processes can mod-
ify content within the mount point which is stored in the container
storage in a separate directory. In overlay terms, the source directory
is the lower, and the container storage directory is the upper. Modifi-
cations to the mount point are destroyed when the container finishes ex-
ecuting, similar to a tmpfs mount point being unmounted.
Note: On SELinux systems, the rootfs needs the correct label, which is
by default unconfined_u:object_r:container_file_t:s0.
idmap
If idmap is specified, create an idmapped mount to the target user name-
space in the container. The idmap option supports a custom mapping that
can be different than the user namespace used by the container. The
mapping can be specified after the idmap option like:
idmap=uids=0-1-10#10-11-10;gids=0-100-10. For each triplet, the first
value is the start of the backing file system IDs that are mapped to the
second value on the host. The length of this mapping is given in the
third value. Multiple ranges are separated with #.
--sdnotify=container | conmon | healthy | ignore
Determines how to use the NOTIFY_SOCKET, as passed with systemd and
Type=notify.
Default is container, which means allow the OCI runtime to proxy the
socket into the container to receive ready notification. Podman sets the
MAINPID to conmon's pid. The conmon option sets MAINPID to conmon's
pid, and sends READY when the container has started. The socket is never
passed to the runtime or the container. The healthy option sets MAINPID
to conmon's pid, and sends READY when the container has turned healthy;
requires a healthcheck to be set. The socket is never passed to the run-
time or the container. The ignore option removes NOTIFY_SOCKET from the
environment for itself and child processes, for the case where some
other process above Podman uses NOTIFY_SOCKET and Podman does not use
it.
--seccomp-policy=policy
Specify the policy to select the seccomp profile. If set to image, Pod-
man looks for a "io.containers.seccomp.profile" label in the container-
image config and use its value as a seccomp profile. Otherwise, Podman
follows the default policy by applying the default profile unless speci-
fied otherwise via --security-opt seccomp as described below.
Note that this feature is experimental and may change in the future.
--secret=secret[,opt=opt ...]
Give the container access to a secret. Can be specified multiple times.
A secret is a blob of sensitive data which a container needs at runtime
but is not stored in the image or in source control, such as usernames
and passwords, TLS certificates and keys, SSH keys or other important
generic strings or binary content (up to 500 kb in size).
When secrets are specified as type mount, the secrets are copied and
mounted into the container when a container is created. When secrets
are specified as type env, the secret is set as an environment variable
within the container. Secrets are written in the container at the time
of container creation, and modifying the secret using podman secret com-
mands after the container is created affects the secret inside the con-
tainer.
Secrets and its storage are managed using the podman secret command.
Secret Options
• type=mount|env : How the secret is exposed to the container.
mount mounts the secret into the container
as a file.
env exposes the secret as an environment
variable.
Defaults to mount.
• target=target : Target of secret.
For mounted secrets, this is the path to
the secret inside the container.
If a fully qualified path is provided, the
secret is mounted at that location.
Otherwise, the secret is mounted to
/run/secrets/target for linux containers or
/var/run/secrets/target for freebsd con-
tainers.
If the target is not set, the secret is
mounted to /run/secrets/secretname by default.
For env secrets, this is the environment
variable key. Defaults to secretname.
• uid=0 : UID of secret. Defaults to 0. Mount secret
type only.
• gid=0 : GID of secret. Defaults to 0. Mount secret
type only.
• mode=0 : Mode of secret. Defaults to 0444. Mount se-
cret type only.
Examples
Mount at /my/location/mysecret with UID 1:
--secret mysecret,target=/my/location/mysecret,uid=1
Mount at /run/secrets/customtarget with mode 0777:
--secret mysecret,target=customtarget,mode=0777
Create a secret environment variable called ENVSEC:
--secret mysecret,type=env,target=ENVSEC
--security-opt=option
Security Options
• apparmor=unconfined : Turn off apparmor confinement for the
container
• apparmor=alternate-profile : Set the apparmor confinement pro-
file for the container
• label=user:USER: Set the label user for the container processes
• label=role:ROLE: Set the label role for the container processes
• label=type:TYPE: Set the label process type for the container
processes
• label=level:LEVEL: Set the label level for the container
processes
• label=filetype:TYPE: Set the label file type for the container
files
• label=disable: Turn off label separation for the container
Note: Labeling can be disabled for all containers by setting label=false
in the containers.conf (/etc/containers/containers.conf or $HOME/.con-
fig/containers/containers.conf) file.
• label=nested: Allows SELinux modifications within the con-
tainer. Containers are allowed to modify SELinux labels on
files and processes, as long as SELinux policy allows. Without
nested, containers view SELinux as disabled, even when it is
enabled on the host. Containers are prevented from setting any
labels.
• mask=/path/1:/path/2: The paths to mask separated by a colon. A
masked path cannot be accessed inside the container.
• no-new-privileges: Disable container processes from gaining ad-
ditional privileges.
• seccomp=unconfined: Turn off seccomp confinement for the con-
tainer.
• seccomp=profile.json: JSON file to be used as a seccomp filter.
Note that the io.podman.annotations.seccomp annotation is set
with the specified value as shown in podman inspect.
• proc-opts=OPTIONS : Comma-separated list of options to use for
the /proc mount. More details for the possible mount options
are specified in the proc(5) man page.
• unmask=ALL or /path/1:/path/2, or shell expanded paths
(/proc/*): Paths to unmask separated by a colon. If set to ALL,
it unmasks all the paths that are masked or made read-only by
default. The default masked paths are /proc/acpi, /proc/kcore,
/proc/keys, /proc/latency_stats, /proc/sched_debug, /proc/scsi,
/proc/timer_list, /proc/timer_stats, /sys/firmware, and
/sys/fs/selinux, /sys/devices/virtual/powercap. The default
paths that are read-only are /proc/asound, /proc/bus, /proc/fs,
/proc/irq, /proc/sys, /proc/sysrq-trigger, /sys/fs/cgroup.
Note: Labeling can be disabled for all containers by setting label=false
in the containers.conf(5) file.
--shm-size=number[unit]
Size of /dev/shm. A unit can be b (bytes), k (kibibytes), m (mebibytes),
or g (gibibytes). If the unit is omitted, the system uses bytes. If the
size is omitted, the default is 64m. When size is 0, there is no limit
on the amount of memory used for IPC by the container. This option con-
flicts with --ipc=host.
--shm-size-systemd=number[unit]
Size of systemd-specific tmpfs mounts such as /run, /run/lock,
/var/log/journal and /tmp. A unit can be b (bytes), k (kibibytes), m
(mebibytes), or g (gibibytes). If the unit is omitted, the system uses
bytes. If the size is omitted, the default is 64m. When size is 0, the
usage is limited to 50% of the host's available memory.
--stop-signal=signal
Signal to stop a container. Default is SIGTERM.
--stop-timeout=seconds
Timeout to stop a container. Default is 10. Remote connections use lo-
cal containers.conf for defaults.
--subgidname=name
Run the container in a new user namespace using the map with name in the
/etc/subgid file. If running rootless, the user needs to have the right
to use the mapping. See subgid(5). This flag conflicts with --userns
and --gidmap.
--subuidname=name
Run the container in a new user namespace using the map with name in the
/etc/subuid file. If running rootless, the user needs to have the right
to use the mapping. See subuid(5). This flag conflicts with --userns
and --uidmap.
--sysctl=name=value
Configure namespaced kernel parameters at runtime.
For the IPC namespace, the following sysctls are allowed:
• kernel.msgmax
• kernel.msgmnb
• kernel.msgmni
• kernel.sem
• kernel.shmall
• kernel.shmmax
• kernel.shmmni
• kernel.shm_rmid_forced
• Sysctls beginning with fs.mqueue.*
Note: if using the --ipc=host option, the above sysctls are not allowed.
For the network namespace, only sysctls beginning with net.* are al-
lowed.
Note: if using the --network=host option, the above sysctls are not al-
lowed.
--systemd=true | false | always
Run container in systemd mode. The default is true.
• true enables systemd mode only when the command executed inside
the container is systemd, /usr/sbin/init, /sbin/init or
/usr/local/sbin/init.
• false disables systemd mode.
• always enforces the systemd mode to be enabled.
Running the container in systemd mode causes the following changes:
• Podman mounts tmpfs file systems on the following directories
• /run
• /run/lock
• /tmp
• /sys/fs/cgroup/systemd (on a cgroup v1 system)
• /var/lib/journal
• Podman sets the default stop signal to SIGRTMIN+3.
• Podman sets container_uuid environment variable in the con-
tainer to the first 32 characters of the container ID.
• Podman does not mount virtual consoles (/dev/tty\d+) when run-
ning with --privileged.
• On cgroup v2, /sys/fs/cgroup is mounted writeable.
This allows systemd to run in a confined container without any modifica-
tions.
Note that on SELinux systems, systemd attempts to write to the cgroup
file system. Containers writing to the cgroup file system are denied by
default. The container_manage_cgroup boolean must be enabled for this
to be allowed on an SELinux separated system.
setsebool -P container_manage_cgroup true
--timeout=seconds
Maximum time a container is allowed to run before conmon sends it the
kill signal. By default containers run until they exit or are stopped
by podman stop.
--tls-verify
Require HTTPS and verify certificates when contacting registries (de-
fault: true). If explicitly set to true, TLS verification is used. If
set to false, TLS verification is not used. If not specified, TLS veri-
fication is used unless the target registry is listed as an insecure
registry in containers-registries.conf(5)
--tmpfs=fs
Create a tmpfs mount.
Mount a temporary filesystem (tmpfs) mount into a container, for exam-
ple:
$ podman create -d --tmpfs /tmp:rw,size=787448k,mode=1777 my_image
This command mounts a tmpfs at /tmp within the container. The supported
mount options are the same as the Linux default mount flags. If no op-
tions are specified, the system uses the following options:
rw,noexec,nosuid,nodev.
--tty, -t
Allocate a pseudo-TTY. The default is false.
When set to true, Podman allocates a pseudo-tty and attach to the stan-
dard input of the container. This can be used, for example, to run a
throwaway interactive shell.
NOTE: The --tty flag prevents redirection of standard output. It com-
bines STDOUT and STDERR, it can insert control characters, and it can
hang pipes. This option is only used when run interactively in a termi-
nal. When feeding input to Podman, use -i only, not -it.
--tz=timezone
Set timezone in container. This flag takes area-based timezones, GMT
time, as well as local, which sets the timezone in the container to
match the host machine. See /usr/share/zoneinfo/ for valid timezones.
Remote connections use local containers.conf for defaults
--uidmap=[flags]container_uid:from_uid[:amount]
Run the container in a new user namespace using the supplied UID map-
ping. This option conflicts with the --userns and --subuidname options.
This option provides a way to map host UIDs to container UIDs. It can be
passed several times to map different ranges.
The possible values of the optional flags are discussed further down on
this page. The amount value is optional and assumed to be 1 if not
given.
The from_uid value is based upon the user running the command, either
rootful or rootless users.
• rootful user: [flags]container_uid:host_uid[:amount]
• rootless user: [flags]container_uid:intermediate_uid[:amount]
Rootful mappings
When podman create is called by a privileged user, the option --uidmap
works as a direct mapping between host UIDs and container UIDs.
host UID -> container UID
The amount specifies the number of consecutive UIDs that is mapped. If
for example amount is 4 the mapping looks like:
┌──────────────┬───────────────────┐
│ host UID │ container UID │
├──────────────┼───────────────────┤
│ from_uid │ container_uid │
├──────────────┼───────────────────┤
│ from_uid + 1 │ container_uid + 1 │
├──────────────┼───────────────────┤
│ from_uid + 2 │ container_uid + 2 │
├──────────────┼───────────────────┤
│ from_uid + 3 │ container_uid + 3 │
└──────────────┴───────────────────┘
Rootless mappings
When podman create is called by an unprivileged user (i.e. running root-
less), the value from_uid is interpreted as an "intermediate UID". In
the rootless case, host UIDs are not mapped directly to container UIDs.
Instead the mapping happens over two mapping steps:
host UID -> intermediate UID -> container UID
The --uidmap option only influences the second mapping step.
The first mapping step is derived by Podman from the contents of the
file /etc/subuid and the UID of the user calling Podman.
First mapping step:
┌─────────────────────┬──────────────────┐
│ host UID │ intermediate UID │
├─────────────────────┼──────────────────┤
│ UID for Podman user │ 0 │
├─────────────────────┼──────────────────┤
│ 1st subordinate UID │ 1 │
├─────────────────────┼──────────────────┤
│ 2nd subordinate UID │ 2 │
├─────────────────────┼──────────────────┤
│ 3rd subordinate UID │ 3 │
├─────────────────────┼──────────────────┤
│ nth subordinate UID │ n │
└─────────────────────┴──────────────────┘
To be able to use intermediate UIDs greater than zero, the user needs to
have subordinate UIDs configured in /etc/subuid. See subuid(5).
The second mapping step is configured with --uidmap.
If for example amount is 5 the second mapping step looks like:
┌──────────────────┬───────────────────┐
│ intermediate UID │ container UID │
├──────────────────┼───────────────────┤
│ from_uid │ container_uid │
├──────────────────┼───────────────────┤
│ from_uid + 1 │ container_uid + 1 │
├──────────────────┼───────────────────┤
│ from_uid + 2 │ container_uid + 2 │
├──────────────────┼───────────────────┤
│ from_uid + 3 │ container_uid + 3 │
├──────────────────┼───────────────────┤
│ from_uid + 4 │ container_uid + 4 │
└──────────────────┴───────────────────┘
When running as rootless, Podman uses all the ranges configured in the
/etc/subuid file.
The current user ID is mapped to UID=0 in the rootless user namespace.
Every additional range is added sequentially afterward:
┌───────────────────────┬─────────────────────────┬──────────────────────┐
│ host │ rootless user namespace │ length │
├───────────────────────┼─────────────────────────┼──────────────────────┤
│ $UID │ 0 │ 1 │
├───────────────────────┼─────────────────────────┼──────────────────────┤
│ 1 │ $FIRST_RANGE_ID │ $FIRST_RANGE_LENGTH │
├───────────────────────┼─────────────────────────┼──────────────────────┤
│ 1+$FIRST_RANGE_LENGTH │ $SECOND_RANGE_ID │ $SECOND_RANGE_LENGTH │
└───────────────────────┴─────────────────────────┴──────────────────────┘
Referencing a host ID from the parent namespace
As a rootless user, the given host ID in --uidmap or --gidmap is mapped
from the intermediate namespace generated by Podman. Sometimes it is de-
sirable to refer directly at the host namespace. It is possible to manu-
ally do so, by running podman unshare cat /proc/self/gid_map, finding
the desired host id at the second column of the output, and getting the
corresponding intermediate id from the first column.
Podman can perform all that by preceding the host id in the mapping with
the @ symbol. For instance, by specifying --gidmap 100000:@2000:1, pod-
man will look up the intermediate id corresponding to host id 2000 and
it will map the found intermediate id to the container id 100000. The
given host id must have been subordinated (otherwise it would not be
mapped into the intermediate space in the first place).
If the length is greater than one, for instance with --gidmap
100000:@2000:2, Podman will map host ids 2000 and 2001 to 100000 and
100001, respectively, regardless of how the intermediate mapping is de-
fined.
Extending previous mappings
Some mapping modifications may be cumbersome. For instance, a user
starts with a mapping such as --gidmap="0:0:65000", that needs to be
changed such as the parent id 1000 is mapped to container id 100000 in-
stead, leaving container id 1 unassigned. The corresponding --gidmap be-
comes --gidmap="0:0:1" --gidmap="2:2:65534" --gidmap="100000:1:1".
This notation can be simplified using the + flag, that takes care of
breaking previous mappings removing any conflicting assignment with the
given mapping. The flag is given before the container id as follows:
--gidmap="0:0:65000" --gidmap="+100000:1:1"
┌──────┬─────────────┬─────────────────────────────┐
│ Flag │ Example │ Description │
├──────┼─────────────┼─────────────────────────────┤
│ + │ +100000:1:1 │ Extend the previous mapping │
└──────┴─────────────┴─────────────────────────────┘
This notation leads to gaps in the assignment, so it may be convenient
to fill those gaps afterwards: --gidmap="0:0:65000"
--gidmap="+100000:1:1" --gidmap="1:65001:1"
One specific use case for this flag is in the context of rootless users.
A rootless user may specify mappings with the + flag as in
--gidmap="+100000:1:1". Podman will then "fill the gaps" starting from
zero with all the remaining intermediate ids. This is convenient when a
user wants to map a specific intermediate id to a container id, leaving
the rest of subordinate ids to be mapped by Podman at will.
Passing only one of --uidmap or --gidmap
Usually, subordinated user and group ids are assigned simultaneously,
and for any user the subordinated user ids match the subordinated group
ids. For convenience, if only one of --uidmap or --gidmap is given,
podman assumes the mapping refers to both UIDs and GIDs and applies the
given mapping to both. If only one value of the two needs to be changed,
the mappings should include the u or the g flags to specify that they
only apply to UIDs or GIDs and should not be copied over.
┌──────┬───────────────┬──────────────────────┐
│ flag │ Example │ Description │
├──────┼───────────────┼──────────────────────┤
│ u │ u20000:2000:1 │ The mapping only ap- │
│ │ │ plies to UIDs │
├──────┼───────────────┼──────────────────────┤
│ g │ g10000:1000:1 │ The mapping only ap- │
│ │ │ plies to GIDs │
└──────┴───────────────┴──────────────────────┘
For instance given the command
podman create --gidmap "0:0:1000" --gidmap "g2000:2000:1"
Since no --uidmap is given, the --gidmap is copied to --uidmap, giving a
command equivalent to
podman create --gidmap "0:0:1000" --gidmap "2000:2000:1" --uidmap "0:0:1000"
The --gidmap "g2000:2000:1" used the g flag and therefore it was not
copied to --uidmap.
Rootless mapping of additional host GIDs
A rootless user may desire to map a specific host group that has already
been subordinated within /etc/subgid without specifying the rest of the
mapping.
This can be done with --gidmap "+gcontainer_gid:@host_gid"
Where:
• The host GID is given through the @ symbol
• The mapping of this GID is not copied over to --usermap thanks
to the g flag.
• The rest of the container IDs will be mapped starting from 0 to
n, with all the remaining subordinated GIDs, thanks to the +
flag.
For instance, if a user belongs to the group 2000 and that group is sub-
ordinated to that user (with usermod --add-subgids 2000-2000 $USER), the
user can map the group into the container with: --gidmap=+g100000:@2000.
If this mapping is combined with the option, --group-add=keep-groups,
the process in the container will belong to group 100000, and files be-
longing to group 2000 in the host will appear as being owned by group
100000 inside the container.
podman run --group-add=keep-groups --gidmap="+g100000:@2000" ...
No subordinate UIDs
Even if a user does not have any subordinate UIDs in /etc/subuid,
--uidmap can be used to map the normal UID of the user to a container
UID by running podman create --uidmap $container_uid:0:1 --user $con-
tainer_uid ....
Pods
The --uidmap option cannot be called in conjunction with the --pod op-
tion as a uidmap cannot be set on the container level when in a pod.
--ulimit=option
Ulimit options. Sets the ulimits values inside of the container.
--ulimit with a soft and hard limit in the format =[:]. For example:
$ podman run --ulimit nofile=1024:1024 --rm ubi9 ulimit -n 1024
Set -1 for the soft or hard limit to set the limit to the maximum limit
of the current process. In rootful mode this is often unlimited.
If nofile and nproc are unset, a default value of 1048576 will be used,
unless overridden in containers.conf(5). However, if the default value
exceeds the hard limit for the current rootless user, the current hard
limit will be applied instead.
Use host to copy the current configuration from the host.
Don't use nproc with the ulimit flag as Linux uses nproc to set the max-
imum number of processes available to a user, not to a container.
Use the --pids-limit option to modify the cgroup control to limit the
number of processes within a container.
--umask=umask
Set the umask inside the container. Defaults to 0022. Remote connec-
tions use local containers.conf for defaults
--unsetenv=env
Unset default environment variables for the container. Default environ-
ment variables include variables provided natively by Podman, environ-
ment variables configured by the image, and environment variables from
containers.conf.
--unsetenv-all
Unset all default environment variables for the container. Default envi-
ronment variables include variables provided natively by Podman, envi-
ronment variables configured by the image, and environment variables
from containers.conf.
--user, -u=user[:group]
Sets the username or UID used and, optionally, the groupname or GID for
the specified command. Both user and group may be symbolic or numeric.
Without this argument, the command runs as the user specified in the
container image. Unless overridden by a USER command in the Container-
file or by a value passed to this option, this user generally defaults
to root.
When a user namespace is not in use, the UID and GID used within the
container and on the host match. When user namespaces are in use, how-
ever, the UID and GID in the container may correspond to another UID and
GID on the host. In rootless containers, for example, a user namespace
is always used, and root in the container by default corresponds to the
UID and GID of the user invoking Podman.
--userns=mode
Set the user namespace mode for the container.
If --userns is not set, the default value is determined as follows. -
If --pod is set, --userns is ignored and the user namespace of the pod
is used. - If the environment variable PODMAN_USERNS is set its value
is used. - If userns is specified in containers.conf this value is
used. - Otherwise, --userns=host is assumed.
--userns="" (i.e., an empty string) is an alias for --userns=host.
This option is incompatible with --gidmap, --uidmap, --subuidname and
--subgidname.
Rootless user --userns=Key mappings:
┌─────────────────────────┬───────────┬──────────────────────┐
│ Key │ Host User │ Container User │
├─────────────────────────┼───────────┼──────────────────────┤
│ auto │ $UID │ nil (Host User UID │
│ │ │ is not mapped into │
│ │ │ container.) │
├─────────────────────────┼───────────┼──────────────────────┤
│ host │ $UID │ 0 (Default User ac- │
│ │ │ count mapped to root │
│ │ │ user in container.) │
├─────────────────────────┼───────────┼──────────────────────┤
│ keep-id │ $UID │ $UID (Map user ac- │
│ │ │ count to same UID │
│ │ │ within container.) │
├─────────────────────────┼───────────┼──────────────────────┤
│ keep-id:uid=200,gid=210 │ $UID │ 200:210 (Map user │
│ │ │ account to specified │
│ │ │ UID, GID value │
│ │ │ within container.) │
├─────────────────────────┼───────────┼──────────────────────┤
│ nomap │ $UID │ nil (Host User UID │
│ │ │ is not mapped into │
│ │ │ container.) │
└─────────────────────────┴───────────┴──────────────────────┘
Valid mode values are:
auto[:OPTIONS,...]: automatically create a unique user namespace.
• rootful mode: The --userns=auto flag requires that the user
name containers be specified in the /etc/subuid and /etc/subgid
files, with an unused range of subordinate user IDs that Podman
containers are allowed to allocate.
Example: containers:2147483647:2147483648.
• rootless mode: The users range from the /etc/subuid and
/etc/subgid files will be used. Note running a single container
without using --userns=auto will use the entire range of UIDs
and not allow further subdividing. See subuid(5).
Podman allocates unique ranges of UIDs and GIDs from the containers sub-
ordinate user IDs. The size of the ranges is based on the number of UIDs
required in the image. The number of UIDs and GIDs can be overridden
with the size option.
The option --userns=keep-id uses all the subuids and subgids of the
user. The option --userns=nomap uses all the subuids and subgids of the
user except the user's own ID. Using --userns=auto when starting new
containers does not work as long as any containers exist that were
started with --userns=nomap or --userns=keep-id without limiting the
user namespace size.
Valid auto options:
• gidmapping=CONTAINER_GID:HOST_GID:SIZE: to force a GID mapping
to be present in the user namespace.
• size=SIZE: to specify an explicit size for the automatic user
namespace. e.g. --userns=auto:size=8192. If size is not speci-
fied, auto estimates a size for the user namespace.
• uidmapping=CONTAINER_UID:HOST_UID:SIZE: to force a UID mapping
to be present in the user namespace.
The host UID and GID in gidmapping and uidmapping can optionally be pre-
fixed with the @ symbol. In this case, podman will look up the interme-
diate ID corresponding to host ID and it will map the found intermediate
ID to the container id. For details see --uidmap.
container:id: join the user namespace of the specified container.
host or "" (empty string): run in the user namespace of the caller. The
processes running in the container have the same privileges on the host
as any other process launched by the calling user.
keep-id: creates a user namespace where the current user's UID:GID are
mapped to the same values in the container. For containers created by
root, the current mapping is created into a new user namespace.
Valid keep-id options:
• uid=UID: override the UID inside the container that is used to
map the current user to.
• gid=GID: override the GID inside the container that is used to
map the current user to.
• size=SIZE: override the size of the configured user namespace.
It is useful to not saturate all the available IDs. Not sup-
ported when running as root.
nomap: creates a user namespace where the current rootless user's
UID:GID are not mapped into the container. This option is not allowed
for containers created by the root user.
ns:namespace: run the container in the given existing user namespace.
--uts=mode
Set the UTS namespace mode for the container. The following values are
supported:
• host: use the host's UTS namespace inside the container.
• private: create a new namespace for the container (default).
• ns:[path]: run the container in the given existing UTS name-
space.
• container:[container]: join the UTS namespace of the specified
container.
--variant=VARIANT
Use VARIANT instead of the default architecture variant of the container
image. Some images can use multiple variants of the arm architectures,
such as arm/v5 and arm/v7.
--volume, -v=[[SOURCE-VOLUME|HOST-DIR:]CONTAINER-DIR[:OPTIONS]]
Create a bind mount. If -v /HOST-DIR:/CONTAINER-DIR is specified, Podman
bind mounts /HOST-DIR from the host into /CONTAINER-DIR in the Podman
container. Similarly, -v SOURCE-VOLUME:/CONTAINER-DIR mounts the named
volume from the host into the container. If no such named volume exists,
Podman creates one. If no source is given, the volume is created as an
anonymously named volume with a randomly generated name, and is removed
when the container is removed via the --rm flag or the podman rm --vol-
umes command.
(Note when using the remote client, including Mac and Windows (excluding
WSL2) machines, the volumes are mounted from the remote server, not nec-
essarily the client machine.)
The OPTIONS is a comma-separated list and can be one or more of:
• rw|ro
• z|Z
• [O]
• [U]
• [no]copy
• [no]dev
• [no]exec
• [no]suid
• [r]bind
• [r]shared|[r]slave|[r]private[r]unbindable [1] ⟨#Footnote1⟩
• idmap[=options]
The CONTAINER-DIR must be an absolute path such as /src/docs. The volume
is mounted into the container at this directory.
If a volume source is specified, it must be a path on the host or the
name of a named volume. Host paths are allowed to be absolute or rela-
tive; relative paths are resolved relative to the directory Podman is
run in. If the source does not exist, Podman returns an error. Users
must pre-create the source files or directories.
Any source that does not begin with a . or / is treated as the name of a
named volume. If a volume with that name does not exist, it is created.
Volumes created with names are not anonymous, and they are not removed
by the --rm option and the podman rm --volumes command.
Specify multiple -v options to mount one or more volumes into a con-
tainer.
Write Protected Volume Mounts
Add :ro or :rw option to mount a volume in read-only or read-write mode,
respectively. By default, the volumes are mounted read-write. See exam-
ples.
Chowning Volume Mounts
By default, Podman does not change the owner and group of source volume
directories mounted into containers. If a container is created in a new
user namespace, the UID and GID in the container may correspond to an-
other UID and GID on the host.
The :U suffix tells Podman to use the correct host UID and GID based on
the UID and GID within the container, to change recursively the owner
and group of the source volume. Chowning walks the file system under the
volume and changes the UID/GID on each file. If the volume has thousands
of inodes, this process takes a long time, delaying the start of the
container.
Warning use with caution since this modifies the host filesystem.
Labeling Volume Mounts
Labeling systems like SELinux require that proper labels are placed on
volume content mounted into a container. Without a label, the security
system might prevent the processes running inside the container from us-
ing the content. By default, Podman does not change the labels set by
the OS.
To change a label in the container context, add either of two suffixes
:z or :Z to the volume mount. These suffixes tell Podman to relabel file
objects on the shared volumes. The z option tells Podman that two or
more containers share the volume content. As a result, Podman labels the
content with a shared content label. Shared volume labels allow all con-
tainers to read/write content. The Z option tells Podman to label the
content with a private unshared label Only the current container can use
a private volume. Note: all containers within a pod share the same
SELinux label. This means all containers within said pod can read/write
volumes shared into the container created with the :Z on any of one the
containers. Relabeling walks the file system under the volume and
changes the label on each file, if the volume has thousands of inodes,
this process takes a long time, delaying the start of the container. If
the volume was previously relabeled with the z option, Podman is opti-
mized to not relabel a second time. If files are moved into the volume,
then the labels can be manually change with the chcon -Rt con-
tainer_file_t PATH command.
Note: Do not relabel system files and directories. Relabeling system
content might cause other confined services on the machine to fail. For
these types of containers we recommend disabling SELinux separation.
The option --security-opt label=disable disables SELinux separation for
the container. For example if a user wanted to volume mount their en-
tire home directory into a container, they need to disable SELinux sepa-
ration.
$ podman create --security-opt label=disable -v $HOME:/home/user fedora touch /home/user/file
Overlay Volume Mounts
The :O flag tells Podman to mount the directory from the host as a tem-
porary storage using the overlay file system. The container processes
can modify content within the mountpoint which is stored in the con-
tainer storage in a separate directory. In overlay terms, the source di-
rectory is the lower, and the container storage directory is the upper.
Modifications to the mount point are destroyed when the container fin-
ishes executing, similar to a tmpfs mount point being unmounted.
For advanced users, the overlay option also supports custom non-volatile
upperdir and workdir for the overlay mount. Custom upperdir and workdir
can be fully managed by the users themselves, and Podman does not remove
it on lifecycle completion. Example :O,upperdir=/some/up-
per,workdir=/some/work
Subsequent executions of the container sees the original source direc-
tory content, any changes from previous container executions no longer
exist.
One use case of the overlay mount is sharing the package cache from the
host into the container to allow speeding up builds.
Note: The O flag conflicts with other options listed above.
Content mounted into the container is labeled with the private label.
On SELinux systems, labels in the source directory must be readable by
the container label. Usually containers can read/execute con-
tainer_share_t and can read/write container_file_t. If unable to change
the labels on a source volume, SELinux container separation must be dis-
abled for the container to work.
Do not modify the source directory mounted into the container with an
overlay mount, it can cause unexpected failures. Only modify the direc-
tory after the container finishes running.
Mounts propagation
By default, bind-mounted volumes are private. That means any mounts done
inside the container are not visible on the host and vice versa. One
can change this behavior by specifying a volume mount propagation prop-
erty. When a volume is shared, mounts done under that volume inside the
container are visible on host and vice versa. Making a volume slave[1]
⟨#Footnote1⟩ enables only one-way mount propagation: mounts done on the
host under that volume are visible inside the container but not the
other way around.
To control mount propagation property of a volume one can use the
[r]shared, [r]slave, [r]private or the [r]unbindable propagation flag.
Propagation property can be specified only for bind mounted volumes and
not for internal volumes or named volumes. For mount propagation to work
the source mount point (the mount point where source dir is mounted on)
has to have the right propagation properties. For shared volumes, the
source mount point has to be shared. And for slave volumes, the source
mount point has to be either shared or slave. [1] ⟨#Footnote1⟩
To recursively mount a volume and all of its submounts into a container,
use the rbind option. By default the bind option is used, and submounts
of the source directory is not mounted into the container.
Mounting the volume with a copy option tells podman to copy content from
the underlying destination directory onto newly created internal vol-
umes. The copy only happens on the initial creation of the volume. Con-
tent is not copied up when the volume is subsequently used on different
containers. The copy option is ignored on bind mounts and has no effect.
Mounting volumes with the nosuid options means that SUID executables on
the volume can not be used by applications to change their privilege. By
default volumes are mounted with nosuid.
Mounting the volume with the noexec option means that no executables on
the volume can be executed within the container.
Mounting the volume with the nodev option means that no devices on the
volume can be used by processes within the container. By default volumes
are mounted with nodev.
If the HOST-DIR is a mount point, then dev, suid, and exec options are
ignored by the kernel.
Use df HOST-DIR to figure out the source mount, then use findmnt -o TAR-
GET,PROPAGATION source-mount-dir to figure out propagation properties of
source mount. If findmnt(1) utility is not available, then one can look
at the mount entry for the source mount point in /proc/self/mountinfo.
Look at the "optional fields" and see if any propagation properties are
specified. In there, shared:N means the mount is shared, master:N means
mount is slave, and if nothing is there, the mount is private. [1]
⟨#Footnote1⟩
To change propagation properties of a mount point, use mount(8) command.
For example, if one wants to bind mount source directory /foo, one can
do mount --bind /foo /foo and mount --make-private --make-shared /foo.
This converts /foo into a shared mount point. Alternatively, one can di-
rectly change propagation properties of source mount. Say / is source
mount for /foo, then use mount --make-shared / to convert / into a
shared mount.
Note: if the user only has access rights via a group, accessing the vol-
ume from inside a rootless container fails.
Idmapped mount
If idmap is specified, create an idmapped mount to the target user name-
space in the container. The idmap option supports a custom mapping that
can be different than the user namespace used by the container. The map-
ping can be specified after the idmap option like:
idmap=uids=0-1-10#10-11-10;gids=0-100-10. For each triplet, the first
value is the start of the backing file system IDs that are mapped to the
second value on the host. The length of this mapping is given in the
third value. Multiple ranges are separated with #.
Use the --group-add keep-groups option to pass the user's supplementary
group access into the container.
--volumes-from=CONTAINER[:OPTIONS]
Mount volumes from the specified container(s). Used to share volumes be-
tween containers. The options is a comma-separated list with the follow-
ing available elements:
• rw|ro
• z
Mounts already mounted volumes from a source container onto another con-
tainer. CONTAINER may be a name or ID. To share a volume, use the
--volumes-from option when running the target container. Volumes can be
shared even if the source container is not running.
By default, Podman mounts the volumes in the same mode (read-write or
read-only) as it is mounted in the source container. This can be
changed by adding a ro or rw option.
Labeling systems like SELinux require that proper labels are placed on
volume content mounted into a container. Without a label, the security
system might prevent the processes running inside the container from us-
ing the content. By default, Podman does not change the labels set by
the OS.
To change a label in the container context, add z to the volume mount.
This suffix tells Podman to relabel file objects on the shared volumes.
The z option tells Podman that two entities share the volume content. As
a result, Podman labels the content with a shared content label. Shared
volume labels allow all containers to read/write content.
If the location of the volume from the source container overlaps with
data residing on a target container, then the volume hides that data on
the target.
--workdir, -w=dir
Working directory inside the container.
The default working directory for running binaries within a container is
the root directory (/). The image developer can set a different default
with the WORKDIR instruction. The operator can override the working di-
rectory by using the -w option.
EXAMPLES
Create a container using a local image:
$ podman create alpine ls
Create a container using a local image and annotate it:
$ podman create --annotation HELLO=WORLD alpine ls
Create a container using a local image, allocating a pseudo-TTY, keeping
stdin open and name it myctr:
podman create -t -i --name myctr alpine ls
Running a container in a new user namespace requires a mapping of the
UIDs and GIDs from the host:
$ podman create --uidmap 0:30000:7000 --gidmap 0:30000:7000 fedora echo hello
Setting automatic user-namespace separated containers:
# podman create --userns=auto:size=65536 ubi8-init
Configure the timezone in a container:
$ podman create --tz=local alpine date
$ podman create --tz=Asia/Shanghai alpine date
$ podman create --tz=US/Eastern alpine date
Ensure the first container (container1) is running before the second
container (container2) is started:
$ podman create --name container1 -t -i fedora bash
$ podman create --name container2 --requires container1 -t -i fedora bash
$ podman start --attach container2
Create a container which requires multiple containers:
$ podman create --name container1 -t -i fedora bash
$ podman create --name container2 -t -i fedora bash
$ podman create --name container3 --requires container1,container2 -t -i fedora bash
$ podman start --attach container3
Expose shared libraries inside of container as read-only using a glob:
$ podman create --mount type=glob,src=/usr/lib64/libnvidia\*,ro -i -t fedora /bin/bash
Create a container allowing supplemental groups to have access to the
volume:
$ podman create -v /var/lib/design:/var/lib/design --group-add keep-groups ubi8
Configure execution domain for containers using the personality option:
$ podman create --name container1 --personality=LINUX32 fedora bash
Create a container with external rootfs mounted as an overlay:
$ podman create --name container1 --rootfs /path/to/rootfs:O bash
Create a container connected to two networks (called net1 and net2) with
a static ip:
$ podman create --network net1:ip=10.89.1.5 --network net2:ip=10.89.10.10 alpine ip addr
Rootless Containers
Podman runs as a non-root user on most systems. This feature requires
that a new enough version of shadow-utils be installed. The shadow-utils
package must include the newuidmap and newgidmap executables.
In order for users to run rootless, there must be an entry for their
username in /etc/subuid and /etc/subgid which lists the UIDs for their
user namespace.
Rootless Podman works better if the fuse-overlayfs and slirp4netns pack-
ages are installed. The fuse-overlayfs package provides a userspace
overlay storage driver, otherwise users need to use the vfs storage dri-
ver, which can be disk space expensive and less performant than other
drivers.
To enable VPN on the container, slirp4netns or pasta needs to be speci-
fied; without either, containers need to be run with the --network=host
flag.
ENVIRONMENT
Environment variables within containers can be set using multiple dif-
ferent options: This section describes the precedence.
Precedence order (later entries override earlier entries):
• --env-host : Host environment of the process executing Podman
is added.
• --http-proxy: By default, several environment variables are
passed in from the host, such as http_proxy and no_proxy. See
--http-proxy for details.
• Container image : Any environment variables specified in the
container image.
• --env-file : Any environment variables specified via env-files.
If multiple files specified, then they override each other in
order of entry.
• --env : Any environment variables specified overrides previous
settings.
Create containers and set the environment ending with a *. The trailing
* glob functionality is only active when no value is specified:
$ export ENV1=a
$ podman create --name ctr1 --env 'ENV*' alpine env
$ podman start --attach ctr1 | grep ENV
ENV1=a
$ podman create --name ctr2 --env 'ENV*=b' alpine env
$ podman start --attach ctr2 | grep ENV
ENV*=b
CONMON
When Podman starts a container it actually executes the conmon program,
which then executes the OCI Runtime. Conmon is the container monitor.
It is a small program whose job is to watch the primary process of the
container, and if the container dies, save the exit code. It also holds
open the tty of the container, so that it can be attached to later. This
is what allows Podman to run in detached mode (backgrounded), so Podman
can exit but conmon continues to run. Each container has their own in-
stance of conmon. Conmon waits for the container to exit, gathers and
saves the exit code, and then launches a Podman process to complete the
container cleanup, by shutting down the network and storage. For more
information about conmon, see the conmon(8) man page.
FILES
/etc/subuid /etc/subgid
NOTE: Use the environment variable TMPDIR to change the temporary stor-
age location of downloaded container images. Podman defaults to use
/var/tmp.
SEE ALSO
podman(1), podman-save(1), podman-ps(1), podman-attach(1), podman-pod-
create(1), podman-port(1), podman-start(1), podman-kill(1), podman-
stop(1), podman-generate-systemd(1), podman-rm(1), subgid(5), subuid(5),
containers.conf(5), systemd.unit(5), setsebool(8), slirp4netns(1),
pasta(1), fuse-overlayfs(1), proc(5), conmon(8), personality(2)
Troubleshooting
See podman-troubleshooting(7) for solutions to common issues.
See podman-rootless(7) for rootless issues.
HISTORY
October 2017, converted from Docker documentation to Podman by Dan Walsh
for Podman <dwalsh@redhat.com>
November 2014, updated by Sven Dowideit <SvenDowideit@home.org.au>
September 2014, updated by Sven Dowideit <SvenDowideit@home.org.au>
August 2014, updated by Sven Dowideit <SvenDowideit@home.org.au>
FOOTNOTES
1: The Podman project is committed to inclusivity, a core value of open
source. The master and slave mount propagation terminology used here is
problematic and divisive, and needs to be changed. However, these terms
are currently used within the Linux kernel and must be used as-is at
this time. When the kernel maintainers rectify this usage, Podman will
follow suit immediately.
podman-create(1)
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