Use the Docker command line

The base command for the Docker CLI is docker. For information about the available flags and subcommands, refer to the CLI reference

Depending on your Docker system configuration, you may be required to preface each docker command with sudo. To avoid having to use sudo with the docker command, your system administrator can create a Unix group called docker and add users to it.

For more information about installing Docker or sudo configuration, refer to the installation instructions for your operating system.

Environment variables

The following list of environment variables are supported by the docker command line:

DOCKER_API_VERSIONOverride the negotiated API version to use for debugging (e.g. 1.19)
DOCKER_CERT_PATHLocation of your authentication keys. This variable is used both by the docker CLI and the dockerd daemon
DOCKER_CONFIGThe location of your client configuration files.
DOCKER_CONTENT_TRUST_SERVERThe URL of the Notary server to use. Defaults to the same URL as the registry.
DOCKER_CONTENT_TRUSTWhen set Docker uses notary to sign and verify images. Equates to --disable-content-trust=false for build, create, pull, push, run.
DOCKER_CONTEXTName of the docker context to use (overrides DOCKER_HOST env var and default context set with docker context use)
DOCKER_DEFAULT_PLATFORMDefault platform for commands that take the --platform flag.
DOCKER_HIDE_LEGACY_COMMANDSWhen set, Docker hides "legacy" top-level commands (such as docker rm, and docker pull) in docker help output, and only Management commands per object-type (e.g., docker container) are printed. This may become the default in a future release.
DOCKER_HOSTDaemon socket to connect to.
DOCKER_TLSEnable TLS for connections made by the docker CLI (equivalent of the --tls command-line option). Set to a non-empty value to enable TLS. Note that TLS is enabled automatically if any of the other TLS options are set.
DOCKER_TLS_VERIFYWhen set Docker uses TLS and verifies the remote. This variable is used both by the docker CLI and the dockerd daemon
BUILDKIT_PROGRESSSet type of progress output (auto, plain, tty, rawjson) when building with BuildKit backend. Use plain to show container output (default auto).

Because Docker is developed using Go, you can also use any environment variables used by the Go runtime. In particular, you may find these useful:

HTTP_PROXYProxy URL for HTTP requests unless overridden by NoProxy.
HTTPS_PROXYProxy URL for HTTPS requests unless overridden by NoProxy.
NO_PROXYComma-separated values specifying hosts that should be excluded from proxying.

See the Go specification for details on these variables.

Configuration files

By default, the Docker command line stores its configuration files in a directory called .docker within your $HOME directory.

Docker manages most of the files in the configuration directory and you shouldn't modify them. However, you can modify the config.json file to control certain aspects of how the docker command behaves.

You can modify the docker command behavior using environment variables or command-line options. You can also use options within config.json to modify some of the same behavior. If an environment variable and the --config flag are set, the flag takes precedent over the environment variable. Command line options override environment variables and environment variables override properties you specify in a config.json file.

Change the .docker directory

To specify a different directory, use the DOCKER_CONFIG environment variable or the --config command line option. If both are specified, then the --config option overrides the DOCKER_CONFIG environment variable. The example below overrides the docker ps command using a config.json file located in the ~/testconfigs/ directory.

$ docker --config ~/testconfigs/ ps

This flag only applies to whatever command is being ran. For persistent configuration, you can set the DOCKER_CONFIG environment variable in your shell (e.g. ~/.profile or ~/.bashrc). The example below sets the new directory to be HOME/newdir/.docker.

$ echo export DOCKER_CONFIG=$HOME/newdir/.docker > ~/.profile

Docker CLI configuration file (config.json) properties

Use the Docker CLI configuration to customize settings for the docker CLI. The configuration file uses JSON formatting, and properties:

By default, configuration file is stored in ~/.docker/config.json. Refer to the change the .docker directory section to use a different location.


The configuration file and other files inside the ~/.docker configuration directory may contain sensitive information, such as authentication information for proxies or, depending on your credential store, credentials for your image registries. Review your configuration file's content before sharing with others, and prevent committing the file to version control.

Customize the default output format for commands

These fields lets you customize the default output format for some commands if no --format flag is provided.

configFormatCustom default format for docker config ls output. See docker config ls for a list of supported formatting directives.
imagesFormatCustom default format for docker images / docker image ls output. See docker images for a list of supported formatting directives.
networksFormatCustom default format for docker network ls output. See docker network ls for a list of supported formatting directives.
nodesFormatCustom default format for docker node ls output. See docker node ls for a list of supported formatting directives.
pluginsFormatCustom default format for docker plugin ls output. See docker plugin ls for a list of supported formatting directives.
psFormatCustom default format for docker ps / docker container ps output. See docker ps for a list of supported formatting directives.
secretFormatCustom default format for docker secret ls output. See docker secret ls for a list of supported formatting directives.
serviceInspectFormatCustom default format for docker service inspect output. See docker service inspect for a list of supported formatting directives.
servicesFormatCustom default format for docker service ls output. See docker service ls for a list of supported formatting directives.
statsFormatCustom default format for docker stats output. See docker stats for a list of supported formatting directives.
tasksFormatCustom default format for docker stack ps output. See docker stack ps for a list of supported formatting directives.
volumesFormatCustom default format for docker volume ls output. See docker volume ls for a list of supported formatting directives.

Custom HTTP headers

The property HttpHeaders specifies a set of headers to include in all messages sent from the Docker client to the daemon. Docker doesn't try to interpret or understand these headers; it simply puts them into the messages. Docker does not allow these headers to change any headers it sets for itself.

Credential store options

The property credsStore specifies an external binary to serve as the default credential store. When this property is set, docker login will attempt to store credentials in the binary specified by docker-credential-<value> which is visible on $PATH. If this property isn't set, credentials are stored in the auths property of the CLI configuration file. For more information, see the Credential stores section in the docker login documentation

The property credHelpers specifies a set of credential helpers to use preferentially over credsStore or auths when storing and retrieving credentials for specific registries. If this property is set, the binary docker-credential-<value> will be used when storing or retrieving credentials for a specific registry. For more information, see the Credential helpers section in the docker login documentation

Automatic proxy configuration for containers

The property proxies specifies proxy environment variables to be automatically set on containers, and set as --build-arg on containers used during docker build. A "default" set of proxies can be configured, and will be used for any Docker daemon that the client connects to, or a configuration per host (Docker daemon), for example, The following properties can be set for each environment:

httpProxyDefault value of HTTP_PROXY and http_proxy for containers, and as --build-arg on docker build
httpsProxyDefault value of HTTPS_PROXY and https_proxy for containers, and as --build-arg on docker build
ftpProxyDefault value of FTP_PROXY and ftp_proxy for containers, and as --build-arg on docker build
noProxyDefault value of NO_PROXY and no_proxy for containers, and as --build-arg on docker build
allProxyDefault value of ALL_PROXY and all_proxy for containers, and as --build-arg on docker build

These settings are used to configure proxy settings for containers only, and not used as proxy settings for the docker CLI or the dockerd daemon. Refer to the environment variables and HTTP/HTTPS proxy sections for configuring proxy settings for the cli and daemon.


Proxy settings may contain sensitive information (for example, if the proxy requires authentication). Environment variables are stored as plain text in the container's configuration, and as such can be inspected through the remote API or committed to an image when using docker commit.

Default key-sequence to detach from containers

Once attached to a container, users detach from it and leave it running using the using CTRL-p CTRL-q key sequence. This detach key sequence is customizable using the detachKeys property. Specify a <sequence> value for the property. The format of the <sequence> is a comma-separated list of either a letter [a-Z], or the ctrl- combined with any of the following:

  • a-z (a single lowercase alpha character )
  • @ (at sign)
  • [ (left bracket)
  • \\ (two backward slashes)
  • _ (underscore)
  • ^ (caret)

Your customization applies to all containers started in with your Docker client. Users can override your custom or the default key sequence on a per-container basis. To do this, the user specifies the --detach-keys flag with the docker attach, docker exec, docker run or docker start command.

CLI plugin options

The property plugins contains settings specific to CLI plugins. The key is the plugin name, while the value is a further map of options, which are specific to that plugin.

Sample configuration file

Following is a sample config.json file to illustrate the format used for various fields:

  "HttpHeaders": {
    "MyHeader": "MyValue"
  "psFormat": "table {{.ID}}\\t{{.Image}}\\t{{.Command}}\\t{{.Labels}}",
  "imagesFormat": "table {{.ID}}\\t{{.Repository}}\\t{{.Tag}}\\t{{.CreatedAt}}",
  "pluginsFormat": "table {{.ID}}\t{{.Name}}\t{{.Enabled}}",
  "statsFormat": "table {{.Container}}\t{{.CPUPerc}}\t{{.MemUsage}}",
  "servicesFormat": "table {{.ID}}\t{{.Name}}\t{{.Mode}}",
  "secretFormat": "table {{.ID}}\t{{.Name}}\t{{.CreatedAt}}\t{{.UpdatedAt}}",
  "configFormat": "table {{.ID}}\t{{.Name}}\t{{.CreatedAt}}\t{{.UpdatedAt}}",
  "serviceInspectFormat": "pretty",
  "nodesFormat": "table {{.ID}}\t{{.Hostname}}\t{{.Availability}}",
  "detachKeys": "ctrl-e,e",
  "credsStore": "secretservice",
  "credHelpers": {
    "": "hip-star",
    "": "vcbait"
  "plugins": {
    "plugin1": {
      "option": "value"
    "plugin2": {
      "anotheroption": "anothervalue",
      "athirdoption": "athirdvalue"
  "proxies": {
    "default": {
      "httpProxy":  "",
      "httpsProxy": "",
      "noProxy":    "",
      "ftpProxy":   "",
      "allProxy":   "socks://"
    "": {
      "httpProxy":  "",
      "httpsProxy": ""

Experimental features

Experimental features provide early access to future product functionality. These features are intended for testing and feedback, and they may change between releases without warning or can be removed from a future release.

Starting with Docker 20.10, experimental CLI features are enabled by default, and require no configuration to enable them.


If using your own notary server and a self-signed certificate or an internal Certificate Authority, you need to place the certificate at tls/<registry_url>/ca.crt in your Docker config directory.

Alternatively you can trust the certificate globally by adding it to your system's list of root Certificate Authorities.


Specify daemon host (-H, --host)

You can use the -H, --host flag to specify a socket to use when you invoke a docker command. You can use the following protocols:

unix://[<path>]Unix socket (Linux only)unix:///var/run/docker.sock
tcp://[<IP or host>[:port]]TCP connectiontcp://
ssh://[username@]<IP or host>[:port]SSH connectionssh://user@
npipe://[<name>]Named pipe (Windows only)npipe:////./pipe/docker_engine

If you don't specify the -H flag, and you're not using a custom context, commands use the following default sockets:

  • unix:///var/run/docker.sock on macOS and Linux
  • npipe:////./pipe/docker_engine on Windows

To achieve a similar effect without having to specify the -H flag for every command, you could also create a context, or alternatively, use the DOCKER_HOST environment variable.

For more information about the -H flag, see Daemon socket option.

Using TCP sockets

The following example shows how to invoke docker ps over TCP, to a remote daemon with IP address, listening on port 2376:

$ docker -H tcp:// ps


By convention, the Docker daemon uses port 2376 for secure TLS connections, and port 2375 for insecure, non-TLS connections.

Using SSH sockets

When you use SSH invoke a command on a remote daemon, the request gets forwarded to the /var/run/docker.sock Unix socket on the SSH host.

$ docker -H ssh://user@ ps

You can optionally specify the location of the socket by appending a path component to the end of the SSH address.

$ docker -H ssh://user@ ps

Display help text

To list the help on any command just execute the command, followed by the --help option.

$ docker run --help

Usage: docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

Create and run a new container from an image

      --add-host value             Add a custom host-to-IP mapping (host:ip) (default [])
  -a, --attach value               Attach to STDIN, STDOUT or STDERR (default [])

Option types

Single character command line options can be combined, so rather than typing docker run -i -t --name test busybox sh, you can write docker run -it --name test busybox sh.


Boolean options take the form -d=false. The value you see in the help text is the default value which is set if you do not specify that flag. If you specify a Boolean flag without a value, this will set the flag to true, irrespective of the default value.

For example, running docker run -d will set the value to true, so your container will run in "detached" mode, in the background.

Options which default to true (e.g., docker build --rm=true) can only be set to the non-default value by explicitly setting them to false:

$ docker build --rm=false .


You can specify options like -a=[] multiple times in a single command line, for example in these commands:

$ docker run -a stdin -a stdout -i -t ubuntu /bin/bash

$ docker run -a stdin -a stdout -a stderr ubuntu /bin/ls

Sometimes, multiple options can call for a more complex value string as for -v:

$ docker run -v /host:/container example/mysql


Do not use the -t and -a stderr options together due to limitations in the pty implementation. All stderr in pty mode simply goes to stdout.

Strings and Integers

Options like --name="" expect a string, and they can only be specified once. Options like -c=0 expect an integer, and they can only be specified once.