Dockerが気になっていたので学ぶことにする。インストール前にオンラインチュートリアルでお勉強
http://www.docker.com/tryit/
ヘルプの表示
dockerコマンドを引数なしで入力するとコマンドの一覧が表示される
Welcome to the interactive Docker tutorial you@tutorial:~$ docker Usage: Docker [OPTIONS] COMMAND [arg...] -H="127.0.0.1:4243": Host:port to bind/connect to A self-sufficient runtime for linux containers. Commands: attach Attach to a running container build Build a container from a Dockerfile commit Create a new image from a container's changes diff Inspect changes on a container's filesystem export Stream the contents of a container as a tar archive history Show the history of an image images List images import Create a new filesystem image from the contents of a tarball info Display system-wide information insert Insert a file in an image inspect Return low-level information on a container kill Kill a running container login Register or Login to the Docker registry server logs Fetch the logs of a container port Lookup the public-facing port which is NAT-ed to PRIVATE_PORT ps List containers pull Pull an image or a repository from the Docker registry server push Push an image or a repository to the Docker registry server restart Restart a running container rm Remove a container rmi Remove an image run Run a command in a new container search Search for an image in the Docker index start Start a stopped container stop Stop a running container tag Tag an image into a repository version Show the Docker version information wait Block until a container stops, then print its exit code
バージョンの確認
versionコマンドを実行。クライアントとサーバー、 DockerはGo言語で記述されているのでGo言語のバージョンが表示される。
you@tutorial:~$ docker version Docker Emulator version 0.1.3 Emulating: Client version: 0.5.3 Server version: 0.5.3 Go version: go1.1
イメージの検索
Dockerのインデックスから既存のイメージを探すにはsearchコマンドを使用する。練習なのでtutorialを探す。learn/tutorialがヒット。これはlearnというユーザーがtutorialというイメージを公開しているという意味になる。
you@tutorial:~$ docker search tutorial
Found 1 results matching your query ("tutorial")
NAME DESCRIPTION
learn/tutorial An image for the interactive tutorial
イメージの取得
Dockerのレジストリサーバーからイメージを取得したい場合はpullコマンドを使う。
you@tutorial:~$ docker pull learn/tutorial Pulling repository learn/tutorial from https://index.docker.io/v1 Pulling image 8dbd9e392a964056420e5d58ca5cc376ef18e2de93b5cc90e868a1bbc8318c1c (precise) from ubuntu Pulling image b750fe79269d2ec9a3c593ef05b4332b1d1a02a62b4accb2c21d589ff2f5f2dc (12.10) from ubuntu Pulling image 27cf784147099545 () from tutorial
コマンドの実行
runコマンドを使うことで対象のイメージに対してshellコマンドを実行できる。
you@tutorial:~$ docker run learn/tutorial echo hello world hello world
モジュールのインストール
同じ要領でモジュールをインストールする。-yオプションを付けて非インタラクティブモードで実行することに注意。
you@tutorial:~$ docker run learn/tutorial apt-get install -y ping Reading package lists... Building dependency tree... The following NEW packages will be installed: iputils-ping 0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. Need to get 56.1 kB of archives. After this operation, 143 kB of additional disk space will be used. Get:1 http://archive.ubuntu.com/ubuntu/ precise/main iputils-ping amd64 3:20101006-1ubuntu1 [56.1 kB] debconf: delaying package configuration, since apt-utils is not installed Fetched 56.1 kB in 1s (50.3 kB/s) Selecting previously unselected package iputils-ping. (Reading database ... 7545 files and directories currently installed.) Unpacking iputils-ping (from .../iputils-ping_3%3a20101006-1ubuntu1_amd64.deb) ... Setting up iputils-ping (3:20101006-1ubuntu1) ...
変更の保存
imageの内容を変更したので保存する。変更した記録はpsで確認できる。IDを指定してcommitする。
you@tutorial:~$ docker ps -l ID IMAGE COMMAND CREATED STATUS PORTS 6982a9948422 ubuntu:12.04 apt-get install ping 1 minute ago Exit 0 you@tutorial:~$ docker commit learn/ping 6982a9948422 effb66b31edb
pingコマンドの実行
pingコマンドを保存したので使えるようになっているかを確認。ctrl-cが効かないので一瞬焦るが10回で停止してくれる。
you@tutorial:~$ docker run learn/ping ping www.google.com PING www.google.com (74.125.239.129) 56(84) bytes of data. 64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=1 ttl=55 time=2.23 ms 64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=2 ttl=55 time=2.30 ms 64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=3 ttl=55 time=2.27 ms 64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=4 ttl=55 time=2.30 ms 64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=5 ttl=55 time=2.25 ms 64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=6 ttl=55 time=2.29 ms 64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=7 ttl=55 time=2.23 ms 64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=8 ttl=55 time=2.30 ms 64 bytes from nuq05s02-in-f20.1e100.net (74.125.239.148): icmp_req=9 ttl=55 time=2.35 ms -> This would normally just keep going. However, this emulator does not support Ctrl-C, so we quit here.
調査
実行中のコンテナはdocker psコマンドで確認できる。次にdocker inspectを使ってこのコンテナについての詳しい情報を得る。
you@tutorial:~$ docker ps
ID IMAGE COMMAND CREATED STATUS PORTS
efefdc74a1d5 learn/ping:latest ping www.google.com 37 seconds ago Up 36 seconds
you@tutorial:~$ docker inspect efefdc74a1d5
[2013/07/30 01:52:26 GET /v1.3/containers/efef/json
{
"ID": "efefdc74a1d5900d7d7a74740e5261c09f5f42b6dae58ded6a1fde1cde7f4ac5",
"Created": "2013-07-30T00:54:12.417119736Z",
"Path": "ping",
"Args": [
"www.google.com"
],
"Config": {
"Hostname": "efefdc74a1d5",
"User": "",
"Memory": 0,
"MemorySwap": 0,
"CpuShares": 0,
"AttachStdin": false,
"AttachStdout": true,
"AttachStderr": true,
"PortSpecs": null,
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": null,
"Cmd": [
"ping",
"www.google.com"
],
"Dns": null,
"Image": "learn/ping",
"Volumes": null,
"VolumesFrom": "",
"Entrypoint": null
},
"State": {
"Running": true,
"Pid": 22249,
"ExitCode": 0,
"StartedAt": "2013-07-30T00:54:12.424817715Z",
"Ghost": false
},
"Image": "a1dbb48ce764c6651f5af98b46ed052a5f751233d731b645a6c57f91a4cb7158",
"NetworkSettings": {
"IPAddress": "172.16.42.6",
"IPPrefixLen": 24,
"Gateway": "172.16.42.1",
"Bridge": "docker0",
"PortMapping": {
"Tcp": {},
"Udp": {}
}
},
"SysInitPath": "/usr/bin/docker",
"ResolvConfPath": "/etc/resolv.conf",
"Volumes": {},
"VolumesRW": {}
レジストリサーバーにpush
imageが出来上がったらサーバーにpushする。
you@tutorial:~$ docker images
ubuntu latest 8dbd9e392a96 4 months ago 131.5 MB (virtual 131.5 MB)
learn/tutorial latest 8dbd9e392a96 2 months ago 131.5 MB (virtual 131.5 MB)
learn/ping latest effb66b31edb 10 minutes ago 11.57 MB (virtual 143.1 MB)
you@tutorial:~$ docker push learn/ping
The push refers to a repository [learn/ping] (len: 1)
Processing checksums
Sending image list
Pushing repository learn/ping (1 tags)
Pushing 8dbd9e392a964056420e5d58ca5cc376ef18e2de93b5cc90e868a1bbc8318c1c
Image 8dbd9e392a964056420e5d58ca5cc376ef18e2de93b5cc90e868a1bbc8318c1c already pushed, skipping
Pushing tags for rev [8dbd9e392a964056420e5d58ca5cc376ef18e2de93b5cc90e868a1bbc8318c1c] on {https://registry-1.docker.io/v1/repositories/learn/ping/tags/l
atest}
Pushing a1dbb48ce764c6651f5af98b46ed052a5f751233d731b645a6c57f91a4cb7158
Pushing 11.5 MB/11.5 MB (100%)
Pushing tags for rev [a1dbb48ce764c6651f5af98b46ed052a5f751233d731b645a6c57f91a4cb7158] on {https://registry-1.docker.io/v1/repositories/learn/ping/tags/l
atest}全て完了するとAAで祝福してくれる。
