path: root/docs/podman-create.1.md

% 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. You can
then use the **podman start** *container* command to start the container at
any point.

The initial status of the container created with **podman create** is 'created'.

## OPTIONS
**--add-host**=*host*

Add a custom host-to-IP mapping (host:ip)

Add a line to /etc/hosts. The format is hostname:ip.  The **--add-host**
option can be set multiple times.

**--annotation**=*key=value*

Add an annotation to the container. The format is key=value.
The **--annotation** option can be set multiple times.

**--attach**, **-a**=*location*

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 standard
error. It can even pretend to be a TTY (this is what most commandline
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}/containers/auth.json

Note: You can also override the default path of the authentication file by setting the REGISTRY\_AUTH\_FILE
environment variable. `export REGISTRY_AUTH_FILE=path` (Not available for remote commands)

**--blkio-weight**=*weight*

Block IO weight (relative weight) accepts a weight value between 10 and 1000.

**--blkio-weight-device**=*weight*

Block IO weight (relative device weight, format: `DEVICE_NAME:WEIGHT`).

**--cap-add**=*capability*

Add Linux capabilities

**--cap-drop**=*capability*

Drop Linux capabilities

**--cgroupns**=*mode*

Set the cgroup namespace mode for the container, by default **host** is used.
    **host**: use the host's cgroup namespace inside the container.
    **container:<NAME|ID>**: join the namespace of the specified container.
    **private**: create a new cgroup namespace.
    **ns:<PATH>**: join the namespace at the specified path.

**--cgroups**=*mode*

Determines whether the container will create CGroups.
Valid values are *enabled* and *disabled*, which the default being *enabled*.
The *disabled* option will force the container to not create CGroups, and thus conflicts with CGroup options (**--cgroupns** and **--cgroup-parent**).

**--cgroup-parent**=*path*

Path to cgroups under which the cgroup for the container will be created. If the path is not absolute, the path is considered to be relative to the cgroups path of the init process. Cgroups will be created if they do not already exist.

**--cidfile**=*id*

Write the container ID to the file

**--conmon-pidfile**=*path*

Write the pid of the `conmon` process to a file. `conmon` runs in a separate process than Podman, so this is necessary when using systemd to restart Podman containers.

**--cpu-count**=*limit*

Limit the number of CPUs available for execution by the container.

On Windows Server containers, this is approximated as a percentage of total CPU usage.

On Windows Server containers, the processor resource controls are mutually exclusive, the order of precedence is CPUCount first, then CPUShares, and CPUPercent last.

**--cpu-period**=*limit*

Limit the CPU CFS (Completely Fair Scheduler) period

Limit the container's CPU usage. This flag tell the kernel to restrict the container's CPU usage to the period you specify.

**--cpu-quota**=*limit*

Limit the CPU CFS (Completely Fair Scheduler) quota

Limit the container's CPU usage. By default, containers run with the full
CPU resource. This flag tell the kernel to restrict the container's CPU usage
to the quota you specify.

**--cpu-rt-period**=*microseconds*

Limit the CPU real-time period in microseconds

Limit the container's Real Time CPU usage. This flag tell the kernel to restrict the container's Real Time CPU usage to the period you specify.

**--cpu-rt-runtime**=*microseconds*

Limit the CPU real-time runtime in microseconds

Limit the containers Real Time CPU usage. This flag 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 could 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 allotted to the parent cgroup.

**--cpu-shares**=*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 weighting relative
to the weighting of all other running containers.

To modify the proportion from the default of 1024, use the **--cpu-shares**
flag to set the weighting to 2 or higher.

The proportion will only apply 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 will vary 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 would receive
50% of the total CPU time. If you add a fourth container 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 you start one
container **{C0}** with **-c=512** running one process, and another container
**{C1}** with **-c=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

**--cpus**=*number*

Number of CPUs. The default is *0.0* which means no limit.

**--cpuset-cpus**=*cpus*

CPUs in which to allow execution (0-3, 0,1)

**--cpuset-mems**=*nodes*

Memory nodes (MEMs) in which to allow execution (0-3, 0,1). Only effective on NUMA systems.

If you have four memory nodes on your system (0-3), use `--cpuset-mems=0,1`
then processes in your container will only use memory from the first
two memory nodes.

**--detach**, **-d**=*true|false*

Detached mode: run the container in the background and print the new container ID. The default is *false*.

At any time you can run **podman ps** in
the other shell to view a list of the running containers. You can reattach to a
detached container with **podman attach**.

When attached in the tty mode, you can detach from the container (and leave it
running) using a configurable key sequence. The default sequence is `ctrl-p,ctrl-q`.
Configure the keys sequence using the **--detach-keys** option, or specifying
it in the **libpod.conf** file: see **libpod.conf(5)** for more information.

**--detach-keys**=*sequence*

Override the key sequence for detaching a container. Format is a single character `[a-Z]` or
a comma separated sequence of `ctrl-<value>`, where `<value>` is one of:
`a-z`, `@`, `^`, `[`, `\\`, `]`, `^` or `_`.

**--device**=*device*

Add a host device to the container. The format is `<device-on-host>[:<device-on-container>][:<permissions>]` (e.g. --device=/dev/sdc:/dev/xvdc:rwm)

**--device-read-bps**=*path*

Limit read rate (bytes per second) from a device (e.g. --device-read-bps=/dev/sda:1mb)

**--device-read-iops**=*path*

Limit read rate (IO per second) from a device (e.g. --device-read-iops=/dev/sda:1000)

**--device-write-bps**=*path*

Limit write rate (bytes per second) to a device (e.g. --device-write-bps=/dev/sda:1mb)

**--device-write-iops**=*path*

Limit write rate (IO per second) to a device (e.g. --device-write-iops=/dev/sda:1000)

**--dns**=*dns*

Set custom DNS servers. Invalid if using **--dns** and **--network** that is set to 'none' or 'container:<name|id>'.

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** flags is necessary for every run.

The special value **none** can be specified to disable creation of **/etc/resolv.conf** in the container by Podman.
The **/etc/resolv.conf** file in the image will be used without changes.

**--dns-option**=*option*

Set custom DNS options. Invalid if using **--dns-option** and **--network** that is set to 'none' or 'container:<name|id>'.

**--dns-search**=*domain*

Set custom DNS search domains. Invalid if using **--dns-search** and **--network** that is set to 'none' or 'container:<name|id>'. (Use --dns-search=. if you don't wish to set the search domain)

**--entrypoint**=*"command"* | *'["command", "arg1", ...]'*

Overwrite the default ENTRYPOINT of the image

This option allows you to overwrite the default entrypoint of 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, so that when you set an ENTRYPOINT you can run the
container as if it were that binary, complete with default options, and you can
pass in more options via the COMMAND. But, sometimes an operator may want to run
something else inside the container, so you can override the default ENTRYPOINT
at runtime by using a **--entrypoint** and a string to specify the new
ENTRYPOINT.

You need to 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 environment variable is specified without a value, Podman will check the host environment for a value and set the variable only if it is set on the host.  If an environment variable ending in __*__ is specified, Podman will search the host environment for variables starting with the prefix and will add those variables to the container.  If an environment variable with a trailing ***** is specified, then a value must be supplied.

See [**Environment**](#environment) note below for precedence and examples.

**--env-host**=*true|false*

Use host environment inside of the container. See **Environment** note below for precedence.

**--env-file**=*file*

Read in a line delimited file of environment variables. See **Environment** note below for precedence.

**--expose**=*port*

Expose a port, or a range of ports (e.g. --expose=3300-3310) to set up port redirection
on the host system.

**--gidmap**=*container_gid:host_gid:amount*

GID map for the user namespace.  Using this flag will run the container with user namespace enabled.  It conflicts with the `--userns` and `--subgidname` flags.

The following example maps uids 0-2000 in the container to the uids 30000-31999 on the host and gids 0-2000 in the container to the gids 30000-31999 on the host. `--gidmap=0:30000:2000`

**--group-add**=*group*

Add additional groups to run as

**--health-cmd**=*"command"* | *'["command", "arg1", ...]'*

Set or alter a healthcheck command for a container. The command is a command to be executed inside your
container that determines your container 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 will be interpreted
as an argument to `/bin/sh -c`.

**--health-interval**=*interval*

Set an interval for the healthchecks (a value of `disable` results in no automatic timer setup) (default "30s")

**--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`

**--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`.

**--hostname**=*name*

Container host name

Sets the container host name that is available inside the container.

**--help**

Print usage statement

**--http-proxy**=*true|false*

By default proxy environment variables are passed into the container if set
for the Podman process.  This can be disabled by setting the `--http-proxy`
option 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 should not use any proxy.  Proxy environment variables specified
for the container in any other way will override the values that would have
been passed thru 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.)

For example, to disable passing these environment variables from host to
container:

`--http-proxy=false`

Defaults to `true`

**--image-volume**, **builtin-volume**=*bind|tmpfs|ignore*

Tells Podman how to handle the builtin image volumes. The options are: 'bind', 'tmpfs', or 'ignore' (default 'bind').
bind: A directory is created inside the container state directory and bind mounted into
the container for the volumes.
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.

**--init-path**=*path*

Path to the container-init binary.

**--interactive**, **i**=*true|false*

Keep STDIN open even if not attached. The default is *false*.

**--ip6**=*ip*

Not implemented

**--ip**=*ip*

Specify a static IP address for the container, for example '10.88.64.128'.
Can only be used if no additional CNI networks to join were specified via '--network=<network-name>', and if the container is not joining another container's network namespace via '--network=container:<name|id>'.
The address must be within the default CNI network's pool (default 10.88.0.0/16).

**--ipc**=*ipc*

Default is to create a private IPC namespace (POSIX SysV IPC) for the container
                'container:<name|id>': reuses another container shared memory, semaphores and message queues
                'host': use the host shared memory,semaphores and message queues inside the container.  Note: the host mode gives the container full access to local shared memory and is therefore considered insecure.
                'ns:<path>' path to an IPC namespace to join.

**--kernel-memory**=*number[unit]*

Kernel memory limit (format: `<number>[<unit>]`, where unit = b (bytes), k (kilobytes), m (megabytes), or g (gigabytes))

Constrains the kernel memory available to a container. If a limit of 0
is specified (not using `--kernel-memory`), the container's kernel memory
is not limited. If you specify a limit, it may be rounded up to a multiple
of the operating system's page size and the value can be very large,
millions of trillions.

**--label**, **-l**=*label*

Add metadata to a container (e.g., --label com.example.key=value)

**--label-file**=*file*

Read in a line delimited file of labels

**--link-local-ip**=*ip*

Not implemented

**--log-driver**="*k8s-file*"

Logging driver for the container.  Currently available options are *k8s-file* and *journald*, with *json-file* aliased to *k8s-file* for scripting compatibility.

**--log-opt**=*path*

Logging driver specific options.  Used to set the path to the container log file.  For example:

`--log-opt path=/var/log/container/mycontainer.json`

**--mac-address**=*address*

Container MAC address (e.g. 92:d0:c6:0a:29:33)

Remember that the MAC address in an Ethernet network must be unique.
The IPv6 link-local address will be based on the device's MAC address
according to RFC4862.

Not currently supported

**--memory**, **-m**=*limit*

Memory limit (format: <number>[<unit>], where unit = b (bytes), k (kilobytes), m (megabytes), or g (gigabytes))

Allows you to constrain the memory available to a container. 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 container's memory is
not limited. The actual limit may be rounded up to a multiple of the operating
system's page size (the value would be very large, that's millions of trillions).

**--memory-reservation**=*limit*

Memory soft limit (format: <number>[<unit>], where unit = b (bytes), k (kilobytes), m (megabytes), or g (gigabytes))

After setting memory reservation, when the system detects memory contention
or low memory, containers are forced to restrict their consumption to their
reservation. So you should always set the value below **--memory**, otherwise the
hard limit will take precedence. By default, memory reservation will be the same
as memory limit.

**--memory-swap**=*limit*

A limit value equal to memory plus swap. Must be used with the  **-m**
(**--memory**) flag. The swap `LIMIT` should always be larger than **-m**
(**--memory**) value.  By default, the swap `LIMIT` will be set to double
the value of --memory.

The format of `LIMIT` is `<number>[<unit>]`. Unit can be `b` (bytes),
`k` (kilobytes), `m` (megabytes), or `g` (gigabytes). If you don't specify a
unit, `b` is used. Set LIMIT to `-1` to enable unlimited swap.

**--memory-swappiness**=*number*

Tune a container's memory swappiness behavior. Accepts an integer between 0 and 100.

**--mount**=*type=TYPE,TYPE-SPECIFIC-OPTION[,...]*

Attach a filesystem mount to the container

Current supported mount TYPES are `bind`, `volume`, and `tmpfs`.

       e.g.

       type=bind,source=/path/on/host,destination=/path/in/container

       type=bind,src=/path/on/host,dst=/path/in/container,relabel=shared

       type=volume,source=vol1,destination=/path/in/container,ro=true

       type=tmpfs,tmpfs-size=512M,destination=/path/in/container

       Common Options:

              · src, source: mount source spec for bind and volume. Mandatory for bind.

              · dst, destination, target: mount destination spec.

              · ro, read-only: true or false (default).

       Options specific to bind:

              · bind-propagation: shared, slave, private, rshared, rslave, or rprivate(default). See also mount(2).

              . bind-nonrecursive: do not setup a recursive bind mount.  By default it is recursive.

              . relabel: shared, private.

       Options specific to tmpfs:

              · tmpfs-size: Size of the tmpfs mount in bytes. Unlimited by default in Linux.

              · tmpfs-mode: File mode of the tmpfs in octal. (e.g. 700 or 0700.) Defaults to 1777 in Linux.

**--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 a name is not assigned
to the container with **--name** then it will generate a random
string name. The name is useful any place you need to identify a container.
This works for both background and foreground containers.

**--network**, **--net**="*bridge*"

Set the Network mode for the container. Invalid if using **--dns**, **--dns-option**, or **--dns-search** with **--network** that is set to 'none' or 'container:<name|id>'.
                'bridge': create a network stack on the default bridge
                'none': no networking
                'container:<name|id>': reuse another container's network stack
                'host': use the Podman host network stack.  Note: the host mode gives the container full access to local system services such as D-bus and is therefore considered insecure.
                '<network-name>|<network-id>': connect to a user-defined network
                'ns:<path>': path to a network namespace to join
                'slirp4netns': use slirp4netns to create a user network stack.  This is the default for rootless containers

**--network-alias**=*alias*

Not implemented

**--no-hosts**=*true|false*

Do not create /etc/hosts for the container.
By default, Podman will manage /etc/hosts, adding the container's own IP address and any hosts from **--add-host**.
**--no-hosts** disables this, and the image's **/etc/host** will be preserved unmodified.
This option conflicts with **--add-host**.

**--oom-kill-disable**=*true|false*

Whether to disable OOM Killer for the container or not.

**--oom-score-adj**=*num*

Tune the host's OOM preferences for containers (accepts -1000 to 1000)

**--pid**=*pid*

Set the PID mode for the container
Default is to create a private PID namespace for the container
                'container:<name|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': join the specified PID namespace

**--pids-limit**=*limit*

Tune the container's pids limit. Set `0` to have unlimited pids for the container. (default "4096" on systems that support PIDS cgroups).

**--pod**=*name*

Run container in an existing pod. If you want Podman to make the pod for you, preference the pod name with `new:`.
To make a pod with more granular options, use the `podman pod create` command before creating a container.

**--privileged**=*true|false*

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 kernel.
This is because by default a container is not allowed to access any devices.
A “privileged” container is given access to all devices.

When the operator executes a privileged container, Podman enables access
to all devices on the host, turns off graphdriver mount options, as well as
turning off most of the security measures protecting the host from the
container.

**--publish**, **-p**=*port*

Publish a container's port, or range of ports, to the host

Format: `ip:hostPort:containerPort | ip::containerPort | hostPort:containerPort | containerPort`
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.
(e.g., `podman run -p 1234-1236:1222-1224 --name thisWorks -t busybox`
but not `podman run -p 1230-1236:1230-1240 --name RangeContainerPortsBiggerThanRangeHostPorts -t busybox`)
With ip: `podman run -p 127.0.0.1:$HOSTPORT:$CONTAINERPORT --name CONTAINER -t someimage`
Use `podman port` to see the actual mapping: `podman port CONTAINER $CONTAINERPORT`

**--publish-all**, **-P**=*true|false*

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. The
default is false. If the operator uses -P (or -p) then Podman will make the
exposed port accessible on the host and the ports will be available to any
client that can reach the host. When using -P, Podman will bind 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**=*missing*

Pull image before creating ("always"|"missing"|"never") (default "missing").
       'missing': default value, attempt to pull the latest image from the registries listed in registries.conf if a local image does not exist.Raise an error if the image is not in any listed registry and is not present locally.
       'always': Pull the image from the first registry it is found in as listed in  registries.conf. Raise an error if not found in the registries, even if the image is present locally.
       'never': do not pull the image from the registry, use only the local version. Raise an error if the image is not present locally.

Defaults to *missing*.

**--quiet**, **-q**

Suppress output information when pulling images

**--read-only**=*true|false*

Mount the container's root filesystem as read only.

By default a container will have its root filesystem writable allowing processes
to write files anywhere.  By specifying the `--read-only` flag the container will have
its root filesystem mounted as read only prohibiting any writes.

**--read-only-tmpfs**=*true|false*

If container is running in --read-only mode, then mount a read-write tmpfs on /run, /tmp, and /var/tmp.  The default is *true*

**--restart**=*policy*

Restart policy to follow when containers exit.
Restart policy will not take effect if a container is stopped via the `podman kill` or `podman stop` commands.
Valid values are:

- `no`                       : Do not restart containers on exit
- `on-failure[:max_retries]` : Restart containers when they exit with a non-0 exit code, retrying indefinitely or until the optional max_retries count is hit
- `always`                   : Restart containers when they exit, regardless of status, retrying indefinitely

Please note that restart will not restart containers after a system reboot.
If this functionality is required in your environment, you can invoke Podman from a systemd unit file, or create an init script for whichever init system is in use.
To generate systemd unit files, please see *podman generate systemd*

**--rm**=*true|false*

Automatically remove the container when it exits. The default is *false*.

Note that the container will not be removed when it could not be created or
started successfully. This allows the user to inspect the container after
failure.

**--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 management, the rootfs
of the container is assumed to be managed externally.

**--security-opt**=*option*

Security Options

- `apparmor=unconfined` : Turn off apparmor confinement for the container
- `apparmor=your-profile` : Set the apparmor confinement profile 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

- `no-new-privileges` : Disable container processes from gaining additional privileges

- `seccomp=unconfined` : Turn off seccomp confinement for the container
- `seccomp=profile.json` :  White listed syscalls seccomp Json file to be used as a seccomp filter

Note: Labeling can be disabled for all containers by setting label=false in the **libpod.conf** (`/etc/containers/libpod.conf`) file.

**--shm-size**=*size*

Size of `/dev/shm` (format: <number>[<unit>], where unit = b (bytes), k (kilobytes), m (megabytes), or g (gigabytes))
If you omit the unit, the system uses bytes. If you omit the size entirely, the system uses `64m`.
When size is `0`, there is no limit on the amount of memory used for IPC by the container.

**--stop-signal**=*SIGTERM*

Signal to stop a container. Default is SIGTERM.

**--stop-timeout**=*seconds*

Timeout (in seconds) to stop a container. Default is 10.

**--subgidname**=*name*

Name for GID map from the `/etc/subgid` file.  Using this flag will run the container with user namespace enabled.  This flag conflicts with `--userns` and `--gidmap`.

**--subuidname**=*name*

Name for UID map from the `/etc/subuid` file.  Using this flag will run the container with user namespace enabled.  This flag conflicts with `--userns` and `--uidmap`.

**--sysctl**=*SYSCTL*

Configure namespaced kernel parameters at runtime

IPC Namespace - current sysctls 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 you use the --ipc=host option these sysctls will not be allowed.

Network Namespace - current sysctls allowed:
    Sysctls beginning with net.*

Note: if you use the --network=host option these sysctls will not be allowed.

**--systemd**=*true|false|always*

Run container in systemd mode. The default is *true*.

The value *always* enforces the systemd mode is enforced without
looking at the executable name.  Otherwise, if set to true and the
command you are running inside the container is systemd or
/usr/sbin/init.

If the command you are running inside of the container is systemd or
/usr/sbin/init, Podman will setup tmpfs mount points in the following
directories:

/run, /run/lock, /tmp, /sys/fs/cgroup/systemd, /var/lib/journal

It will also set the default stop signal to SIGRTMIN+3.

This allow systemd to run in a confined container without any modifications.

Note: 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`

**--tmpfs**=*fs*

Create a tmpfs mount

Mount a temporary filesystem (`tmpfs`) mount into a container, for example:

$ podman run -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 you do not specify
any options, the systems uses the following options:
`rw,noexec,nosuid,nodev`.

**--tty**, **-t**=*true|false*

Allocate a pseudo-TTY. The default is *false*.

When set to true Podman will allocate a pseudo-tty and attach to the standard
input of the container. This can be used, for example, to run a throwaway
interactive shell. The default is false.

Note: The **-t** option is incompatible with a redirection of the Podman client
standard input.

**--uidmap**=*container_uid:host_uid:amount*

UID map for the user namespace.  Using this flag will run the container with user namespace enabled.  It conflicts with the `--userns` and `--subuidname` flags.

The following example maps uids 0-2000 in the container to the uids 30000-31999 on the host and gids 0-2000 in the container to the gids 30000-31999 on the host. `--uidmap=0:30000:2000`

**--ulimit**=*option*

Ulimit options

You can pass `host` to copy the current configuration from the host.

**--user**, **-u**=*user*

Sets the username or UID used and optionally the groupname or GID for the specified command.

The followings examples are all valid:
--user [user | user:group | uid | uid:gid | user:gid | uid:group ]

Without this argument the command will be run as root in the container.

**--userns**=*host*
**--userns**=*keep-id*
**--userns**=container:container
**--userns**=*ns:my_namespace*

Set the user namespace mode for the container.  It defaults to the **PODMAN_USERNS** environment variable.  An empty value means user namespaces are disabled.

- `host`: run in the user namespace of the caller. This is the default if no user namespace options are set. The processes running in the container will 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 rootless user's UID:GID are mapped to the same values in the container. This option is ignored for containers created by the root user.
- `ns`: run the container in the given existing user namespace.
- `container`: join the user namespace of the specified container.

This option is incompatible with --gidmap, --uidmap, --subuid and --subgid

**--uts**=*host*

Set the UTS mode for the container
    **host**: use the host's UTS namespace inside the container.
    **ns**: specify the user namespace to use.
    Note: the host mode gives the container access to changing the host's hostname and is therefore considered insecure.

**--volume**, **-v**[=*[HOST-DIR:CONTAINER-DIR[:OPTIONS]]*]

Create a bind mount. If you specify, ` -v /HOST-DIR:/CONTAINER-DIR`, podman
bind mounts `/HOST-DIR` in the host to `/CONTAINER-DIR` in the podman
container. The `OPTIONS` are a comma delimited list and can be:

* [rw|ro]
* [z|Z]
* [`[r]shared`|`[r]slave`|`[r]private`]

The `CONTAINER-DIR` must be an absolute path such as `/src/docs`. The `HOST-DIR`
must be an absolute path as well. Podman bind-mounts the `HOST-DIR` to the
path you specify. For example, if you supply the `/foo` value, Podman creates a bind-mount.

You can specify multiple  **-v** options to mount one or more mounts to a
container.

You can add `:ro` or `:rw` suffix to a volume to mount it  read-only or
read-write mode, respectively. By default, the volumes are mounted read-write.
See examples.

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 using the content. By
default, Podman does not change the labels set by the OS.

To change a label in the container context, you can 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 containers
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.
The `Z` option tells Podman to label the content with a private unshared label.
Only the current container can use a private volume.

By default bind mounted volumes are `private`. That means any mounts done
inside container will not be visible on host and vice versa. One can change
this behavior by specifying a volume mount propagation property. Making a
volume `shared` mounts done under that volume inside container will be
visible on host and vice versa. Making a volume `slave` enables only one
way mount propagation and that is mounts done on host under that volume
will be visible inside container but not the other way around.

To control mount propagation property of volume one can use `:[r]shared`,
`:[r]slave` or `:[r]private` 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 source mount point (mount point
where source dir is mounted on) has to have right propagation properties. For
shared volumes, source mount point has to be shared. And for slave volumes,
source mount has to be either shared or slave.

Use `df <source-dir>` to figure out the source mount and then use
`findmnt -o TARGET,PROPAGATION <source-mount-dir>` to figure out propagation
properties of source mount. If `findmnt` utility is not available, then one
can look at mount entry for source mount point in `/proc/self/mountinfo`. Look
at `optional fields` and see if any propagation properties are specified.
`shared:X` means mount is `shared`, `master:X` means mount is `slave` and if
nothing is there that means mount is `private`.

To change propagation properties of a mount point use `mount` 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
will convert /foo into a `shared` mount point. Alternatively one can directly
change propagation properties of source mount. Say `/` is source mount for
`/foo`, then use `mount --make-shared /` to convert `/` into a `shared` mount.

**--volumes-from**[=*CONTAINER*[:*OPTIONS*]]

Mount volumes from the specified container(s).
*OPTIONS* is a comma delimited list with the following available elements:

* [rw|ro]
* z

Mounts already mounted volumes from a source container onto another
container. You must supply the source's container-id or container-name.
To share a volume, use the --volumes-from option when running
the target container. You can share volumes 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. Optionally, you
can change this by suffixing the container-id with either the `ro` or
`rw` keyword.

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 using the content. By
default, Podman does not change the labels set by the OS.

To change a label in the container context, you can 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 containers 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 directory 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
```

### Set UID/GID mapping in a new user namespace

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
```

### 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.

Note: RHEL7 and Centos 7 will not have this feature until RHEL7.7 is released.

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 packages are installed.
The fuse-overlay package provides a userspace overlay storage driver, otherwise users need to use
the vfs storage driver, which is diskspace expensive and does not perform well. slirp4netns is
required for VPN, without it containers need to be run with the --net=host flag.

## ENVIRONMENT

Environment variables within containers can be set using multiple different options:  This section describes the precedence.

Precedence Order:
	   **--env-host** : Host environment of the process executing Podman is added.

	   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 will override previous settings.

Create containers and set the environment ending with a __*__ and a *****

```
$ export ENV1=a
$ podman create --name ctr --env ENV* alpine printenv ENV1
$ podman start --attach ctr
a

$ podman create --name ctr --env ENV*****=b alpine printenv ENV*****
$ podman start --attach ctr
b
```

## FILES

**/etc/subuid**
**/etc/subgid**

## SEE ALSO
subgid(5), subuid(5), libpod.conf(5), systemd.unit(5), setsebool(8), slirp4netns(1), fuse-overlayfs(1)

## 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>