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 instructions for your operating system. This may become the default in a future release, at which point this environment-variable is removed. Because Docker is developed using Go, you can also use any environment variables used by the Go runtime. See the for details on these variables. Configuration files By default, the Docker command line stores its configuration files in a directory docker run arguments. Docker manages most of the files in the configuration directory and you should not modify them. However, you can modify the config. Currently, you can modify the docker command behavior using environment variables or command-line options. You can also use options within config. When using docker run arguments mechanisms, docker run arguments must keep in mind the order of precedence among them. Command line options override environment variables and environment variables override properties you specify in a config. Docker does not try to interpret or understand these header; it simply puts them into the messages. Docker does not allow these headers to change any headers it sets for itself. The property psFormat specifies the default format for docker ps output. If this property is not set, the client falls back to the default table format. For a list of supported formatting directives, see the The property imagesFormat specifies the default format for docker images output. If this property is not set, the client falls back to docker run arguments default table format. For a list of supported formatting directives, see the The property pluginsFormat specifies the default format for docker plugin ls output. If this property is not set, the client falls back to the default table format. For a list of supported formatting directives, see the The property servicesFormat specifies the default format for docker service ls output. If this property is not set, the client falls back to the default json format. For a list of supported formatting directives, see the The property serviceInspectFormat specifies the default format for docker service inspect output. If this property is not set, the client falls back to the default json format. For a list of supported formatting directives, see the The property statsFormat specifies the default format for docker stats output. If this property is not set, the client falls back to the default table format. For a list of supported formatting directives, see The property secretFormat specifies the default format for docker docker run arguments ls output. If this property is not set, the client falls back to the default table format. For a list of supported formatting directives, see The property nodesFormat specifies the default format for docker node ls output. If the value of nodesFormat is not set, the client uses the default table format. For a list of supported formatting directives, see the The property configFormat specifies the default format for docker config ls output. If this property is not set, the client falls back to the default table format. For a list of supported formatting directives, see The property credsStore specifies an external binary to serve as the default credential store. If this property is not set, credentials will be stored in the auths property of the config. For more information, see the 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- will be used when storing or retrieving credentials for a specific registry. For more information, see the The property stackOrchestrator specifies the default orchestrator to use when running docker stack management commands. This detach key sequence is customizable using the detachKeys property. Specify a value for the property. 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. Following is a sample config. Examples Display help text To list the help on any command just execute the command, followed by the --help option. 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. 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. Options which default to true e. All stderr in pty mode simply goes to stdout.