Evaluate Swarm in a sandbox を参考に Docker Swarm を試してみます。
Swarm クラスタを構築するための docker machine を作成する
docker-machine の現状確認
$ docker-machine ls
NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS
default - virtualbox Stopped Unknown
今は不要なので削除しちゃう（残したままでも問題ない）
$ docker-machine rm default
About to remove default
Are you sure? (y/n): y
Successfully removed default
マネージャー用サーバー (manager) 作成
$ docker-machine create -d virtualbox manager
Running pre-create checks...
(manager) Default Boot2Docker ISO is out-of-date, downloading the latest release...
(manager) Latest release for github.com/boot2docker/boot2docker is v1.10.3
(manager) Downloading /home/ytera/.docker/machine/cache/boot2docker.iso from https://github.com/boot2docker/boot2docker/releases/download/v1.10.3/boot2docker.iso...
(manager) 0%....10%....20%....30%....40%....50%....60%....70%....80%....90%....100%
Creating machine...
(manager) Copying /home/ytera/.docker/machine/cache/boot2docker.iso to /home/ytera/.docker/machine/machines/manager/boot2docker.iso...
(manager) Creating VirtualBox VM...
(manager) Creating SSH key...
(manager) Starting the VM...
(manager) Check network to re-create if needed...
(manager) Waiting for an IP...
Waiting for machine to be running, this may take a few minutes...
Detecting operating system of created instance...
Waiting for SSH to be available...
Detecting the provisioner...
Provisioning with boot2docker...
Copying certs to the local machine directory...
Copying certs to the remote machine...
Setting Docker configuration on the remote daemon...
Checking connection to Docker...
Docker is up and running!
To see how to connect your Docker Client to the Docker Engine running on this virtual machine, run: docker-machine env manager
エージェント用サーバーを2台 (agent1, agent2) 作成する
$ docker-machine create -d virtualbox agent1
Running pre-create checks...
Creating machine...
(agent1) Copying /home/ytera/.docker/machine/cache/boot2docker.iso to /home/ytera/.docker/machine/machines/agent1/boot2docker.iso...
(agent1) Creating VirtualBox VM...
(agent1) Creating SSH key...
(agent1) Starting the VM...
(agent1) Check network to re-create if needed...
(agent1) Waiting for an IP...
Waiting for machine to be running, this may take a few minutes...
Detecting operating system of created instance...
Waiting for SSH to be available...
Detecting the provisioner...
Provisioning with boot2docker...
Copying certs to the local machine directory...
Copying certs to the remote machine...
Setting Docker configuration on the remote daemon...
Checking connection to Docker...
Docker is up and running!
To see how to connect your Docker Client to the Docker Engine running on this virtual machine, run: docker-machine env agent1
$ docker-machine create -d virtualbox agent2
Running pre-create checks...
Creating machine...
(agent2) Copying /home/ytera/.docker/machine/cache/boot2docker.iso to /home/ytera/.docker/machine/machines/agent2/boot2docker.iso...
(agent2) Creating VirtualBox VM...
(agent2) Creating SSH key...
(agent2) Starting the VM...
(agent2) Check network to re-create if needed...
(agent2) Waiting for an IP...
Waiting for machine to be running, this may take a few minutes...
Detecting operating system of created instance...
Waiting for SSH to be available...
Detecting the provisioner...
Provisioning with boot2docker...
Copying certs to the local machine directory...
Copying certs to the remote machine...
Setting Docker configuration on the remote daemon...
Checking connection to Docker...
Docker is up and running!
To see how to connect your Docker Client to the Docker Engine running on this virtual machine, run: docker-machine env agent2
作成した docker machine の確認
$ docker-machine ls
NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS
agent1 - virtualbox Running tcp://192.168.99.101:2376 v1.10.3
agent2 - virtualbox Running tcp://192.168.99.102:2376 v1.10.3
manager - virtualbox Running tcp://192.168.99.100:2376 v1.10.3
Swarm ディスカバリトークンの作成
docker コマンドで manager サーバーの操作をするように環境変数を設定する
$ eval $(docker-machine env manager)
$ printenv | grep DOCKER
DOCKER\_HOST=tcp://192.168.99.100:2376
DOCKER\_MACHINE\_NAME=manager
DOCKER\_TLS\_VERIFY=1
DOCKER\_CERT\_PATH=/home/ytera/.docker/machine/machines/manager
Swarm クラスタ用のユニークID（ディスカバリトークン）を生成する
$ docker run --rm swarm create
Unable to find image 'swarm:latest' locally
latest: Pulling from library/swarm
25da0aa87182: Pull complete
45707a9f4c2b: Pull complete
7f0c09406c8f: Pull complete
a3ed95caeb02: Pull complete
Digest: sha256:5f2b4066b2f7e97a326a8bfcfa623be26ce45c26ffa18ea63f01de045d2238f3
Status: Downloaded newer image for swarm:latest
2aba3c5381a6783e37980a8ef90fa41a
2aba3c5381a6783e37980a8ef90fa41a がディスカバリトークンになります。どこか安全な場所にメモっておきます。 docker コマンドに --rm を指定して実行したので create コマンド実行後すぐに実行したイメージが削除されています。
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
Swarm マネージャとノードを作成する
docker-machine の状態確認
$ docker-machine ls
NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS
agent1 - virtualbox Running tcp://192.168.99.101:2376 v1.10.3
agent2 - virtualbox Running tcp://192.168.99.102:2376 v1.10.3
manager * virtualbox Running tcp://192.168.99.100:2376 v1.10.3
次のようにして manager を起動します。manager マシンの 3376 ポートを container の 3376 ポートにマッピングしています。/var/lib/boot2docker を container の /certs にマウントしています。先ほど生成したディスカバリトークンを token:// で指定しています。
$ docker run -d -p 3376:3376 -t -v /var/lib/boot2docker:/certs:ro \
swarm manage -H 0.0.0.0:3376 --tlsverify \
--tlscacert=/certs/ca.pem --tlscert=/certs/server.pem \
--tlskey=/certs/server-key.pem \
token://2aba3c5381a6783e37980a8ef90fa41a
17ba16d89bda270965e534474fd06d5698bcde0aa14397403fb2e970612cd763
/var/lib/boot2docker とは docker-machine で作成した boot2docker サーバーの /var/lib/boot2docker です。次のように manager マシンに ssh でログインすると確認できます。
$ docker-machine ssh manager
## .
## ## ## ==
## ## ## ## ## ===
/"""""""""""""""""\___/ ===
~~~ {~~ ~~~~ ~~~ ~~~~ ~~~ ~ / ===- ~~~
\______ o __/
\ \ __/
\____\_______/
_ _ ____ _ _
| |__ ___ ___ | |_|___ \ __| | ___ ___| | _____ _ __
| '_ \ / _ \ / _ \| __| __) / _` |/ _ \ / __| |/ / _ \ '__|
| |_) | (_) | (_) | |_ / __/ (_| | (_) | (__| < __/ |
|_.__/ \___/ \___/ \__|_____\__,_|\___/ \___|_|\_\___|_|
Boot2Docker version 1.10.3, build master : 625117e - Thu Mar 10 22:09:02 UTC 2016
Docker version 1.10.3, build 20f81dd
docker@manager:~$ sudo ls /var/lib/boot2docker/
ca.pem etc profile server.pem tls
docker.log log server-key.pem ssh userdata.tar
docker@manager:~$
manager コンテナが起動していることを確認してみます。
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
17ba16d89bda swarm "/swarm manage -H 0.0" About a minute ago Up About a minute 2375/tcp, 0.0.0.0:3376->3376/tcp lonely_ritchie
続いて agent1 の操作に移ります docker コマンドの接続先を agent1 に切り替えます
$ eval $(docker-machine env agent1)
swarm コンテナを先ほどのディスカバリトークンを使って join させます
$ docker run -d swarm join --addr=$(docker-machine ip agent1):2376 \
token://2aba3c5381a6783e37980a8ef90fa41a
Unable to find image 'swarm:latest' locally
latest: Pulling from library/swarm
25da0aa87182: Pull complete
45707a9f4c2b: Pull complete
7f0c09406c8f: Pull complete
a3ed95caeb02: Pull complete
Digest: sha256:5f2b4066b2f7e97a326a8bfcfa623be26ce45c26ffa18ea63f01de045d2238f3
Status: Downloaded newer image for swarm:latest
171d5b1abb2c3840b831591a2c4fb231e68703bb2b3a05237cae84e6682e433f
さらに agent2
$ eval $(docker-machine env agent2)
$ docker run -d swarm join --addr=$(docker-machine ip agent2):2376 \
token://2aba3c5381a6783e37980a8ef90fa41a
Unable to find image 'swarm:latest' locally
latest: Pulling from library/swarm
25da0aa87182: Pull complete
45707a9f4c2b: Pull complete
7f0c09406c8f: Pull complete
a3ed95caeb02: Pull complete
Digest: sha256:5f2b4066b2f7e97a326a8bfcfa623be26ce45c26ffa18ea63f01de045d2238f3
Status: Downloaded newer image for swarm:latest
3f5c29f68c65334607622a89cafde0268d229ec365646326cd15ef60b5b06f42
agent は manager に対してオレはこの IP と Port で待ってるからよろしくって参加している感じだけどマルチキャストでも使ってるのかな？後で調べよう。 → Docker Hub as a hosted discovery service を使ってました
Swarm マネージャの管理
$ DOCKER_HOST=$(docker-machine ip manager):3376
$ docker info
Containers: 2
Running: 2
Paused: 0
Stopped: 0
Images: 2
Server Version: swarm/1.1.3
Role: primary
Strategy: spread
Filters: health, port, dependency, affinity, constraint
Nodes: 2
agent1: 192.168.99.101:2376
└ Status: Healthy
└ Containers: 1
└ Reserved CPUs: 0 / 1
└ Reserved Memory: 0 B / 1.021 GiB
└ Labels: executiondriver=native-0.2, kernelversion=4.1.19-boot2docker, operatingsystem=Boot2Docker 1.10.3 (TCL 6.4.1); master : 625117e - Thu Mar 10 22:09:02 UTC 2016, provider=virtualbox, storagedriver=aufs
└ Error: (none)
└ UpdatedAt: 2016-03-15T15:05:38Z
agent2: 192.168.99.102:2376
└ Status: Healthy
└ Containers: 1
└ Reserved CPUs: 0 / 1
└ Reserved Memory: 0 B / 1.021 GiB
└ Labels: executiondriver=native-0.2, kernelversion=4.1.19-boot2docker, operatingsystem=Boot2Docker 1.10.3 (TCL 6.4.1); master : 625117e - Thu Mar 10 22:09:02 UTC 2016, provider=virtualbox, storagedriver=aufs
└ Error: (none)
└ UpdatedAt: 2016-03-15T15:05:59Z
Plugins:
Volume:
Network:
Kernel Version: 4.1.19-boot2docker
Operating System: linux
Architecture: amd64
CPUs: 2
Total Memory: 2.043 GiB
Name: 17ba16d89bda
agent1, agent2 の Swarm クラスタが構成されているっぽいですね。
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
試しに hello-world コンテナを実行してみます
$ docker run hello-world
Hello from Docker.
This message shows that your installation appears to be working correctly.
To generate this message, Docker took the following steps:
1. The Docker client contacted the Docker daemon.
2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
3. The Docker daemon created a new container from that image which runs the
executable that produces the output you are currently reading.
4. The Docker daemon streamed that output to the Docker client, which sent it
to your terminal.
To try something more ambitious, you can run an Ubuntu container with:
$ docker run -it ubuntu bash
Share images, automate workflows, and more with a free Docker Hub account:
https://hub.docker.com
For more examples and ideas, visit:
https://docs.docker.com/userguide/
agent1 上で実行されたようです。
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0c20dcb512c7 hello-world "/hello" 8 seconds ago Exited (0) 7 seconds ago agent1/naughty_jennings
3f5c29f68c65 swarm "/swarm join --addr=1" 9 minutes ago Up 9 minutes 2375/tcp agent2/thirsty_yonath
171d5b1abb2c swarm "/swarm join --addr=1" 11 minutes ago Up 11 minutes 2375/tcp agent1/amazing_ride
まだまだ Swarm のことはわからないが Evaluate Swarm in a sandbox ページの内容はこれで終わり。 Docker Swarm を順に試していこう。