docker create

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Edge only: This is the CLI reference for Docker CE Edge versions. Some of these options may not be available to Docker CE stable or Docker EE. You can view the stable version of this CLI reference or learn about Docker CE Edge.

Description

Create a new container

Usage

docker create [OPTIONS] IMAGE [COMMAND] [ARG...]

Options

Name, shorthand Default Description
--add-host Add a custom host-to-IP mapping (host:ip)
--attach , -a Attach to STDIN, STDOUT or STDERR
--blkio-weight Block IO (relative weight), between 10 and 1000, or 0 to disable (default 0)
--blkio-weight-device Block IO weight (relative device weight)
--cap-add Add Linux capabilities
--cap-drop Drop Linux capabilities
--cgroup-parent Optional parent cgroup for the container
--cidfile Write the container ID to the file
--cpu-count CPU count (Windows only)
--cpu-percent CPU percent (Windows only)
--cpu-period Limit CPU CFS (Completely Fair Scheduler) period
--cpu-quota Limit CPU CFS (Completely Fair Scheduler) quota
--cpu-rt-period API 1.25+
Limit CPU real-time period in microseconds
--cpu-rt-runtime API 1.25+
Limit CPU real-time runtime in microseconds
--cpu-shares , -c CPU shares (relative weight)
--cpus API 1.25+
Number of CPUs
--cpuset-cpus CPUs in which to allow execution (0-3, 0,1)
--cpuset-mems MEMs in which to allow execution (0-3, 0,1)
--device Add a host device to the container
--device-cgroup-rule Add a rule to the cgroup allowed devices list
--device-read-bps Limit read rate (bytes per second) from a device
--device-read-iops Limit read rate (IO per second) from a device
--device-write-bps Limit write rate (bytes per second) to a device
--device-write-iops Limit write rate (IO per second) to a device
--disable-content-trust true Skip image verification
--dns Set custom DNS servers
--dns-opt Set DNS options
--dns-option Set DNS options
--dns-search Set custom DNS search domains
--entrypoint Overwrite the default ENTRYPOINT of the image
--env , -e Set environment variables
--env-file Read in a file of environment variables
--expose Expose a port or a range of ports
--group-add Add additional groups to join
--health-cmd Command to run to check health
--health-interval Time between running the check (ms|s|m|h) (default 0s)
--health-retries Consecutive failures needed to report unhealthy
--health-start-period API 1.29+
Start period for the container to initialize before starting health-retries countdown (ms|s|m|h) (default 0s)
--health-timeout Maximum time to allow one check to run (ms|s|m|h) (default 0s)
--help Print usage
--hostname , -h Container host name
--init API 1.25+
Run an init inside the container that forwards signals and reaps processes
--interactive , -i Keep STDIN open even if not attached
--io-maxbandwidth Maximum IO bandwidth limit for the system drive (Windows only)
--io-maxiops Maximum IOps limit for the system drive (Windows only)
--ip IPv4 address (e.g., 172.30.100.104)
--ip6 IPv6 address (e.g., 2001:db8::33)
--ipc IPC mode to use
--isolation Container isolation technology
--kernel-memory Kernel memory limit
--label , -l Set meta data on a container
--label-file Read in a line delimited file of labels
--link Add link to another container
--link-local-ip Container IPv4/IPv6 link-local addresses
--log-driver Logging driver for the container
--log-opt Log driver options
--mac-address Container MAC address (e.g., 92:d0:c6:0a:29:33)
--memory , -m Memory limit
--memory-reservation Memory soft limit
--memory-swap Swap limit equal to memory plus swap: ‘-1’ to enable unlimited swap
--memory-swappiness -1 Tune container memory swappiness (0 to 100)
--mount Attach a filesystem mount to the container
--name Assign a name to the container
--net Connect a container to a network
--net-alias Add network-scoped alias for the container
--network Connect a container to a network
--network-alias Add network-scoped alias for the container
--no-healthcheck Disable any container-specified HEALTHCHECK
--oom-kill-disable Disable OOM Killer
--oom-score-adj Tune host’s OOM preferences (-1000 to 1000)
--pid PID namespace to use
--pids-limit Tune container pids limit (set -1 for unlimited)
--platform experimental (daemon)API 1.32+
Set platform if server is multi-platform capable
--privileged Give extended privileges to this container
--publish , -p Publish a container’s port(s) to the host
--publish-all , -P Publish all exposed ports to random ports
--read-only Mount the container’s root filesystem as read only
--restart no Restart policy to apply when a container exits
--rm Automatically remove the container when it exits
--runtime Runtime to use for this container
--security-opt Security Options
--shm-size Size of /dev/shm
--stop-signal SIGTERM Signal to stop a container
--stop-timeout API 1.25+
Timeout (in seconds) to stop a container
--storage-opt Storage driver options for the container
--sysctl Sysctl options
--tmpfs Mount a tmpfs directory
--tty , -t Allocate a pseudo-TTY
--ulimit Ulimit options
--user , -u Username or UID (format: <name|uid>[:<group|gid>])
--userns User namespace to use
--uts UTS namespace to use
--volume , -v Bind mount a volume
--volume-driver Optional volume driver for the container
--volumes-from Mount volumes from the specified container(s)
--workdir , -w Working directory inside the container

Parent command

Command Description
docker The base command for the Docker CLI.

Extended description

The docker create command creates a writeable 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 docker run -d except the container is never started. You can then use the docker start <container_id> command to start the container at any point.

This is useful when you want to set up a container configuration ahead of time so that it is ready to start when you need it. The initial status of the new container is created.

Please see the run command section and the Docker run reference for more details.

Examples

Create and start a container

$ docker create -t -i fedora bash

6d8af538ec541dd581ebc2a24153a28329acb5268abe5ef868c1f1a261221752

$ docker start -a -i 6d8af538ec5

bash-4.2#

Initialize volumes

As of v1.4.0 container volumes are initialized during the docker create phase (i.e., docker run too). For example, this allows you to create the data volume container, and then use it from another container:

$ docker create -v /data --name data ubuntu

240633dfbb98128fa77473d3d9018f6123b99c454b3251427ae190a7d951ad57

$ docker run --rm --volumes-from data ubuntu ls -la /data

total 8
drwxr-xr-x  2 root root 4096 Dec  5 04:10 .
drwxr-xr-x 48 root root 4096 Dec  5 04:11 ..

Similarly, create a host directory bind mounted volume container, which can then be used from the subsequent container:

$ docker create -v /home/docker:/docker --name docker ubuntu

9aa88c08f319cd1e4515c3c46b0de7cc9aa75e878357b1e96f91e2c773029f03

$ docker run --rm --volumes-from docker ubuntu ls -la /docker

total 20
drwxr-sr-x  5 1000 staff  180 Dec  5 04:00 .
drwxr-xr-x 48 root root  4096 Dec  5 04:13 ..
-rw-rw-r--  1 1000 staff 3833 Dec  5 04:01 .ash_history
-rw-r--r--  1 1000 staff  446 Nov 28 11:51 .ashrc
-rw-r--r--  1 1000 staff   25 Dec  5 04:00 .gitconfig
drwxr-sr-x  3 1000 staff   60 Dec  1 03:28 .local
-rw-r--r--  1 1000 staff  920 Nov 28 11:51 .profile
drwx--S---  2 1000 staff  460 Dec  5 00:51 .ssh
drwxr-xr-x 32 1000 staff 1140 Dec  5 04:01 docker

Set storage driver options per container.

$ docker create -it --storage-opt size=120G fedora /bin/bash

This (size) will allow to set the container rootfs size to 120G at creation time. This option is only available for the devicemapper, btrfs, overlay2, windowsfilter and zfs graph drivers. For the devicemapper, btrfs, windowsfilter and zfs graph drivers, user cannot pass a size less than the Default BaseFS Size. For the overlay2 storage driver, the size option is only available if the backing fs is xfs and mounted with the pquota mount option. Under these conditions, user can pass any size less than the backing fs size.

Specify isolation technology for container (--isolation)

This option is useful in situations where you are running Docker containers on Windows. The --isolation=<value> option sets a container’s isolation technology. On Linux, the only supported is the default option which uses Linux namespaces. On Microsoft Windows, you can specify these values:

Value Description
default Use the value specified by the Docker daemon’s --exec-opt . If the daemon does not specify an isolation technology, Microsoft Windows uses process as its default value if the
daemon is running on Windows server, or hyperv if running on Windows client.  
process Namespace isolation only.
hyperv Hyper-V hypervisor partition-based isolation.

Specifying the --isolation flag without a value is the same as setting --isolation="default".

Dealing with dynamically created devices (--device-cgroup-rule)

Devices available to a container are assigned at creation time. The assigned devices will both be added to the cgroup.allow file and created into the container once it is run. This poses a problem when a new device needs to be added to running container.

One of the solution is to add a more permissive rule to a container allowing it access to a wider range of devices. For example, supposing our container needs access to a character device with major 42 and any number of minor number (added as new devices appear), the following rule would be added:

docker create --device-cgroup-rule='c 42:* rmw' -name my-container my-image

Then, a user could ask udev to execute a script that would docker exec my-container mknod newDevX c 42 <minor> the required device when it is added.

NOTE: initially present devices still need to be explicitely added to the create/run command