前回 の記事で似た操作を複数の方法で呼び出せることを確認しましたが， そもそも通常のコマンド(Commands)と管理用のコマンド(Management Commands) はどう違うのだろうと探していたら，下記の記事を見つけました．
この記事はDockerの公式ブログでDocker 1.13の変化点について記載されている記事です． この中の”CLI restructed”の節で，サブコマンドが増えて補完が効かせづらかったり煩雑になってきたのでまとめると書かれています．
この記事を読んだときは，通常のコマンドをすべて管理用のコマンドに集約するのかと思いましたが， 普段Dockerを使っていてコマンドが利用できなくなるといった警告は見たことがないので結局どちらを使えばよいのだろう？ と考えつつ公式ドキュメントを眺めていると，通常のコマンドを隠す環境変数が用意されていることに気づきました．
Use the Docker command line#Environment variables
環境変数DOCKER_HIDE_LEGACY_COMMANDSを設定すると Usageにて表示されるコマンドを管理用コマンドと一部のコマンドに絞ることができます．
通常時のUsageの表示
$ docker
Usage: docker [OPTIONS] COMMAND
A self-sufficient runtime for containers
Options:
--config string Location of client config files (default "/home/USERNAME/.docker")
-c, --context string Name of the context to use to connect to the daemon (overrides DOCKER_HOST env var and default context set
with "docker context use")
-D, --debug Enable debug mode
-H, --host list Daemon socket(s) to connect to
-l, --log-level string Set the logging level ("debug"|"info"|"warn"|"error"|"fatal") (default "info")
--tls Use TLS; implied by --tlsverify
--tlscacert string Trust certs signed only by this CA (default "/home/USERNAME/.docker/ca.pem")
--tlscert string Path to TLS certificate file (default "/home/USERNAME/.docker/cert.pem")
--tlskey string Path to TLS key file (default "/home/USERNAME/.docker/key.pem")
--tlsverify Use TLS and verify the remote
-v, --version Print version information and quit
Management Commands:
builder Manage builds
config Manage Docker configs
container Manage containers
context Manage contexts
engine Manage the docker engine
image Manage images
network Manage networks
node Manage Swarm nodes
plugin Manage plugins
secret Manage Docker secrets
service Manage services
stack Manage Docker stacks
swarm Manage Swarm
system Manage Docker
trust Manage trust on Docker images
volume Manage volumes
Commands:
attach Attach local standard input, output, and error streams to a running container
build Build an image from a Dockerfile
commit Create a new image from a container's changes
cp Copy files/folders between a container and the local filesystem
create Create a new container
diff Inspect changes to files or directories on a container's filesystem
events Get real time events from the server
exec Run a command in a running container
export Export a container's filesystem as a tar archive
history Show the history of an image
images List images
import Import the contents from a tarball to create a filesystem image
info Display system-wide information
inspect Return low-level information on Docker objects
kill Kill one or more running containers
load Load an image from a tar archive or STDIN
login Log in to a Docker registry
logout Log out from a Docker registry
logs Fetch the logs of a container
pause Pause all processes within one or more containers
port List port mappings or a specific mapping for the container
ps List containers
pull Pull an image or a repository from a registry
push Push an image or a repository to a registry
rename Rename a container
restart Restart one or more containers
rm Remove one or more containers
rmi Remove one or more images
run Run a command in a new container
save Save one or more images to a tar archive (streamed to STDOUT by default)
search Search the Docker Hub for images
start Start one or more stopped containers
stats Display a live stream of container(s) resource usage statistics
stop Stop one or more running containers
tag Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE
top Display the running processes of a container
unpause Unpause all processes within one or more containers
update Update configuration of one or more containers
version Show the Docker version information
wait Block until one or more containers stop, then print their exit codes
Run 'docker COMMAND --help' for more information on a command.
環境変数設定時のUsageの表示
$ DOCKER_HIDE_LEGACY_COMMANDS=1 docker
Usage: docker [OPTIONS] COMMAND
A self-sufficient runtime for containers
Options:
--config string Location of client config files (default "/home/USERNAME/.docker")
-c, --context string Name of the context to use to connect to the daemon (overrides DOCKER_HOST env var and default context set
with "docker context use")
-D, --debug Enable debug mode
-H, --host list Daemon socket(s) to connect to
-l, --log-level string Set the logging level ("debug"|"info"|"warn"|"error"|"fatal") (default "info")
--tls Use TLS; implied by --tlsverify
--tlscacert string Trust certs signed only by this CA (default "/home/USERNAME/.docker/ca.pem")
--tlscert string Path to TLS certificate file (default "/home/USERNAME/.docker/cert.pem")
--tlskey string Path to TLS key file (default "/home/USERNAME/.docker/key.pem")
--tlsverify Use TLS and verify the remote
-v, --version Print version information and quit
Management Commands:
builder Manage builds
config Manage Docker configs
container Manage containers
context Manage contexts
engine Manage the docker engine
image Manage images
network Manage networks
node Manage Swarm nodes
plugin Manage plugins
secret Manage Docker secrets
service Manage services
stack Manage Docker stacks
swarm Manage Swarm
system Manage Docker
trust Manage trust on Docker images
volume Manage volumes
Commands:
build Build an image from a Dockerfile
login Log in to a Docker registry
logout Log out from a Docker registry
run Run a command in a new container
search Search the Docker Hub for images
version Show the Docker version information
Run 'docker COMMAND --help' for more information on a command.
上で見比べてみるとわかりますが，かなりの数の通常コマンドが非表示になっています． ですが，全てのコマンドが管理用のコマンドに集約されるわけではないようで， build, run, searchといった頻繁に使うコマンドは非表示になっていません．
次回以降は各管理用のコマンドについて勉強がてら1つずつ調べていこうと思います．