github.com/vieux/docker@v0.6.3-0.20161004191708-e097c2a938c7/man/docker-config-json.5.md (about) 1 % CONFIG.JSON(5) Docker User Manuals 2 % Docker Community 3 % JANUARY 2016 4 # NAME 5 HOME/.docker/config.json - Default Docker configuration file 6 7 # INTRODUCTION 8 9 By default, the Docker command line stores its configuration files in a 10 directory called `.docker` within your `$HOME` directory. Docker manages most of 11 the files in the configuration directory and you should not modify them. 12 However, you *can modify* the `config.json` file to control certain aspects of 13 how the `docker` command behaves. 14 15 Currently, you can modify the `docker` command behavior using environment 16 variables or command-line options. You can also use options within 17 `config.json` to modify some of the same behavior. When using these 18 mechanisms, you must keep in mind the order of precedence among them. Command 19 line options override environment variables and environment variables override 20 properties you specify in a `config.json` file. 21 22 The `config.json` file stores a JSON encoding of several properties: 23 24 * The `HttpHeaders` property specifies a set of headers to include in all messages 25 sent from the Docker client to the daemon. Docker does not try to interpret or 26 understand these header; it simply puts them into the messages. Docker does not 27 allow these headers to change any headers it sets for itself. 28 29 * The `psFormat` property specifies the default format for `docker ps` output. 30 When the `--format` flag is not provided with the `docker ps` command, 31 Docker's client uses this property. If this property is not set, the client 32 falls back to the default table format. For a list of supported formatting 33 directives, see **docker-ps(1)**. 34 35 * The `detachKeys` property specifies the default key sequence which 36 detaches the container. When the `--detach-keys` flag is not provide 37 with the `docker attach`, `docker exec`, `docker run` or `docker 38 start`, Docker's client uses this property. If this property is not 39 set, the client falls back to the default sequence `ctrl-p,ctrl-q`. 40 41 42 * The `imagesFormat` property specifies the default format for `docker images` 43 output. When the `--format` flag is not provided with the `docker images` 44 command, Docker's client uses this property. If this property is not set, the 45 client falls back to the default table format. For a list of supported 46 formatting directives, see **docker-images(1)**. 47 48 You can specify a different location for the configuration files via the 49 `DOCKER_CONFIG` environment variable or the `--config` command line option. If 50 both are specified, then the `--config` option overrides the `DOCKER_CONFIG` 51 environment variable: 52 53 docker --config ~/testconfigs/ ps 54 55 This command instructs Docker to use the configuration files in the 56 `~/testconfigs/` directory when running the `ps` command. 57 58 ## Examples 59 60 Following is a sample `config.json` file: 61 62 { 63 "HttpHeaders": { 64 "MyHeader": "MyValue" 65 }, 66 "psFormat": "table {{.ID}}\\t{{.Image}}\\t{{.Command}}\\t{{.Labels}}", 67 "imagesFormat": "table {{.ID}}\\t{{.Repository}}\\t{{.Tag}}\\t{{.CreatedAt}}", 68 "detachKeys": "ctrl-e,e" 69 } 70 71 # HISTORY 72 January 2016, created by Moxiegirl <mary@docker.com>