CONFIG.JSON(5) Docker User Manuals CONFIG.JSON(5)
NAME
HOME/.docker/config.json - Default Docker configuration file
INTRODUCTION
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 should not
modify them. However, you can modify the config.json file to control
certain aspects of how the docker command behaves.
Currently, you can modify the docker command behavior using environment
variables or command-line options. You can also use options within con-
fig.json to modify some of the same behavior. When using these mecha-
nisms, you must keep in mind the order of precedence among them. Com-
mand line options override environment variables and environment vari-
ables override properties you specify in a config.json file.
The config.json file stores a JSON encoding of several properties:
• The HttpHeaders property specifies a set of headers to include in all
messages sent from the Docker client to the daemon. 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 head-
ers it sets for itself.
• The psFormat property specifies the default format for docker ps out-
put. When the --format flag is not provided with the docker ps com-
mand, Docker's client uses this property. If this property is not
set, the client falls back to the default table format. For a list of
supported formatting directives, see docker-ps(1).
• The detachKeys property specifies the default key sequence which de-
taches the container. When the --detach-keys flag is not provide with
the docker attach, docker exec, docker run or docker start, Docker's
client uses this property. If this property is not set, the client
falls back to the default sequence ctrl-p,ctrl-q.
• The imagesFormat property specifies the default format for docker
images output. When the --format flag is not provided with the docker
images command, Docker's client uses this property. If this property
is not set, the client falls back to the default table format. For a
list of supported formatting directives, see docker-images(1).
You can specify a different location for the configuration files via
the DOCKER_CONFIG environment variable or the --config command line op-
tion. If both are specified, then the --config option overrides the
DOCKER_CONFIG environment variable:
docker --config ~/testconfigs/ ps
This command instructs Docker to use the configuration files in the
~/testconfigs/ directory when running the ps command.
Examples
Following is a sample config.json file:
{
"HttpHeaders": {
"MyHeader": "MyValue"
},
"psFormat": "table {{.ID}}\\t{{.Image}}\\t{{.Command}}\\t{{.Labels}}",
"imagesFormat": "table {{.ID}}\\t{{.Repository}}\\t{{.Tag}}\\t{{.CreatedAt}}",
"detachKeys": "ctrl-e,e"
}
HISTORY
January 2016, created by Moxiegirl mary@docker.com
⟨mailto:mary@docker.com⟩
Docker Community JANUARY 2016 CONFIG.JSON(5)
Generated by dwww version 1.14 on Sat Jun 13 09:42:54 CEST 2026.