--- title: "create" description: "The create command description and usage" keywords: "docker, create, container" --- # create Creates a new container. ```markdown Usage: docker create [OPTIONS] IMAGE [COMMAND] [ARG...] Create a new container Options: --add-host value Add a custom host-to-IP mapping (host:ip) (default []) -a, --attach value Attach to STDIN, STDOUT or STDERR (default []) --blkio-weight value Block IO (relative weight), between 10 and 1000 --blkio-weight-device value Block IO weight (relative device weight) (default []) --cap-add value Add Linux capabilities (default []) --cap-drop value Drop Linux capabilities (default []) --cgroup-parent string Optional parent cgroup for the container --cidfile string Write the container ID to the file --cpu-count int The number of CPUs available for execution by the container. Windows daemon only. On Windows Server containers, this is approximated as a percentage of total CPU usage. --cpu-percent int CPU percent (Windows only) --cpu-period int Limit CPU CFS (Completely Fair Scheduler) period --cpu-quota int Limit CPU CFS (Completely Fair Scheduler) quota -c, --cpu-shares int CPU shares (relative weight) --cpus NanoCPUs Number of CPUs (default 0.000) --cpu-rt-period int Limit the CPU real-time period in microseconds --cpu-rt-runtime int Limit the CPU real-time runtime in microseconds --cpuset-cpus string CPUs in which to allow execution (0-3, 0,1) --cpuset-mems string MEMs in which to allow execution (0-3, 0,1) --device value Add a host device to the container (default []) --device-cgroup-rule value Add a rule to the cgroup allowed devices list --device-read-bps value Limit read rate (bytes per second) from a device (default []) --device-read-iops value Limit read rate (IO per second) from a device (default []) --device-write-bps value Limit write rate (bytes per second) to a device (default []) --device-write-iops value Limit write rate (IO per second) to a device (default []) --disable-content-trust Skip image verification (default true) --dns value Set custom DNS servers (default []) --dns-option value Set DNS options (default []) --dns-search value Set custom DNS search domains (default []) --entrypoint string Overwrite the default ENTRYPOINT of the image -e, --env value Set environment variables (default []) --env-file value Read in a file of environment variables (default []) --expose value Expose a port or a range of ports (default []) --group-add value Add additional groups to join (default []) --health-cmd string Command to run to check health --health-interval duration Time between running the check (ns|us|ms|s|m|h) (default 0s) --health-retries int Consecutive failures needed to report unhealthy --health-timeout duration Maximum time to allow one check to run (ns|us|ms|s|m|h) (default 0s) --help Print usage -h, --hostname string Container host name --init Run an init inside the container that forwards signals and reaps processes --init-path string Path to the docker-init binary -i, --interactive Keep STDIN open even if not attached --io-maxbandwidth string Maximum IO bandwidth limit for the system drive (Windows only) --io-maxiops uint Maximum IOps limit for the system drive (Windows only) --ip string IPv4 address (e.g., 172.30.100.104) --ip6 string IPv6 address (e.g., 2001:db8::33) --ipc string IPC namespace to use --isolation string Container isolation technology --kernel-memory string Kernel memory limit -l, --label value Set meta data on a container (default []) --label-file value Read in a line delimited file of labels (default []) --link value Add link to another container (default []) --link-local-ip value Container IPv4/IPv6 link-local addresses (default []) --log-driver string Logging driver for the container --log-opt value Log driver options (default []) --mac-address string Container MAC address (e.g., 92:d0:c6:0a:29:33) -m, --memory string Memory limit --memory-reservation string Memory soft limit --memory-swap string Swap limit equal to memory plus swap: '-1' to enable unlimited swap --memory-swappiness int Tune container memory swappiness (0 to 100) (default -1) --name string Assign a name to the container --network-alias value Add network-scoped alias for the container (default []) --network string Connect a container to a network (default "default") 'bridge': create a network stack on the default Docker bridge 'none': no networking 'container:': reuse another container's network stack 'host': use the Docker host network stack '|': connect to a user-defined network --no-healthcheck Disable any container-specified HEALTHCHECK --oom-kill-disable Disable OOM Killer --oom-score-adj int Tune host's OOM preferences (-1000 to 1000) --pid string PID namespace to use --pids-limit int Tune container pids limit (set -1 for unlimited), kernel >= 4.3 --privileged Give extended privileges to this container -p, --publish value Publish a container's port(s) to the host (default []) -P, --publish-all Publish all exposed ports to random ports --read-only Mount the container's root filesystem as read only --restart string Restart policy to apply when a container exits (default "no") Possible values are: no, on-failure[:max-retry], always, unless-stopped --rm Automatically remove the container when it exits --runtime string Runtime to use for this container --security-opt value Security Options (default []) --shm-size bytes Size of /dev/shm The format is ``. `number` must be greater than `0`. Unit is optional and can be `b` (bytes), `k` (kilobytes), `m` (megabytes), or `g` (gigabytes). If you omit the unit, the system uses bytes. --stop-signal string Signal to stop a container (default "SIGTERM") --stop-timeout=10 Timeout (in seconds) to stop a container --storage-opt value Storage driver options for the container (default []) --sysctl value Sysctl options (default map[]) --tmpfs value Mount a tmpfs directory (default []) -t, --tty Allocate a pseudo-TTY --ulimit value Ulimit options (default []) -u, --user string Username or UID (format: [:]) --userns string User namespace to use 'host': Use the Docker host user namespace '': Use the Docker daemon user namespace specified by `--userns-remap` option. --uts string UTS namespace to use -v, --volume value Bind mount a volume (default []). The format is `[host-src:]container-dest[:]`. The comma-delimited `options` are [rw|ro], [z|Z], [[r]shared|[r]slave|[r]private], [delegated|cached|consistent], and [nocopy]. The 'host-src' is an absolute path or a name value. --volume-driver string Optional volume driver for the container --volumes-from value Mount volumes from the specified container(s) (default []) -w, --workdir string Working directory inside the container ``` ## 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 ` 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](run.md) section and the [Docker run reference](../run.md) for more details. ## Examples ### Create and start a container ```bash $ 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: ```bash $ 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: ```bash $ 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. ```bash $ 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 then 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=` 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 ` the required device when it is added. NOTE: initially present devices still need to be explicitely added to the create/run command