• 创建docker swarm应用
    • 需要使用到的images
    • 使用V3版本的compose文件
    • 部署
    • 检查
    • 总结

    创建docker swarm应用

    下面以docker官网上的创建vote投票示例来说明如何创建一个docker swarm的应用。

    在进行如下步骤时，你需要保证已经部署并正常运行着一个docker swarm集群。

    在这个应用中你将学到

    • 通过创建docker-stack.yml和使用docker stack deploy命令来部署应用
    • 使用visualizer来查看应用的运行时
    • 更新docker-stack.yml和vote镜像重新部署和发布vote 应用
    • 使用Compose Version 3

    vote-app-diagram

    需要使用到的images

    Service 描述 Base image
    vote Presents the voting interface via port 5000. Viewable at :5000 Based on a Python image, dockersamples/examplevotingapp_vote
    result Displays the voting results via port 5001. Viewable at :5001 Based on a Node.js image, dockersamples/examplevotingapp_result
    visulizer A web app that shows a map of the deployment of the various services across the available nodes via port 8080. Viewable at :8080 Based on a Node.js image, dockersamples/visualizer
    redis Collects raw voting data and stores it in a key/value queue Based on a redis image, redis:alpine
    db A PostgreSQL service which provides permanent storage on a host volume Based on a postgres image, postgres:9.4
    worker A background service that transfers votes from the queue to permanent storage Based on a .NET image, dockersamples/examplevotingapp_worker

    用到的镜像有：

    • dockersamples/examplevotingapp_vote:before
    • dockersamples/examplevotingapp_worker
    • dockersamples/examplevotingapp_result:before
    • dockersamples/visualizer:stable
    • postgres:9.4
    • redis:alpine

    我们将这些images同步到我们的私有镜像仓库sz-pg-oam-docker-hub-001.tendcloud.com中。

    镜像名称分别为：

    • sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_vote:before
    • sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_worker
    • sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_result:before
    • sz-pg-oam-docker-hub-001.tendcloud.com/library/visualizer:stable
    • sz-pg-oam-docker-hub-001.tendcloud.com/library/postgres:9.4
    • sz-pg-oam-docker-hub-001.tendcloud.com/library/redis:alpine

    使用V3版本的compose文件

    v3版本的compose与v2版本的区别

    docker-stack.yml配置

    1. version: "3"
    2. services:
    4.   redis:
    5.     image: sz-pg-oam-docker-hub-001.tendcloud.com/library/redis:alpine
    6.     ports:
    7.       - "6379"
    8.     networks:
    9.       - frontend
    10.     deploy:
    11.       replicas: 2
    12.       update_config:
    13.         parallelism: 2
    14.         delay: 10s
    15.       restart_policy:
    16.         condition: on-failure
    17.   db:
    18.     image: sz-pg-oam-docker-hub-001.tendcloud.com/library/postgres:9.4
    19.     volumes:
    20.       - db-data:/var/lib/postgresql/data
    21.     networks:
    22.       - backend
    23.     deploy:
    24.       placement:
    25.         constraints: [node.role == manager]
    26.   vote:
    27.     image: sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_vote:before
    28.     ports:
    29.       - 5000:80
    30.     networks:
    31.       - frontend
    32.     depends_on:
    33.       - redis
    34.     deploy:
    35.       replicas: 2
    36.       update_config:
    37.         parallelism: 2
    38.       restart_policy:
    39.         condition: on-failure
    40.   result:
    41.     image: sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_result:before
    42.     ports:
    43.       - 5001:80
    44.     networks:
    45.       - backend
    46.     depends_on:
    47.       - db
    48.     deploy:
    49.       replicas: 2
    50.       update_config:
    51.         parallelism: 2
    52.         delay: 10s
    53.       restart_policy:
    54.         condition: on-failure
    56.   worker:
    57.     image: sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_worker
    58.     networks:
    59.       - frontend
    60.       - backend
    61.     deploy:
    62.       mode: replicated
    63.       replicas: 1
    64.       labels: [APP=VOTING]
    65.       restart_policy:
    66.         condition: on-failure
    67.         delay: 10s
    68.         max_attempts: 3
    69.         window: 120s
    71.   visualizer:
    72.     image: sz-pg-oam-docker-hub-001.tendcloud.com/library/visualizer:stable
    73.     ports:
    74.       - "8080:8080"
    75.     stop_grace_period: 1m30s
    76.     volumes:
    77.       - "/var/run/docker.sock:/var/run/docker.sock"
    78.     deploy:
    79.       placement:
    80.         constraints: [node.role == manager]
    82. networks:
    83.   frontend:
    84.   backend:
    86. volumes:
    87.   db-data:

    部署

    使用docker stack deploy命令部署vote应用。

    1. $docker stack deploy -c docker-stack.yml vote
    2. Creating network vote_backend
    3. Creating network vote_frontend
    4. Creating network vote_default
    5. Creating service vote_db
    6. Creating service vote_vote
    7. Creating service vote_result
    8. Creating service vote_worker
    9. Creating service vote_visualizer
    10. Creating service vote_redis

    使用docker stack deploy部署的应用中的images必须是已经在镜像仓库中存在的，而不能像之前的docker-compose up一样，可以通过本地构建镜像后启动。

    使用docker stack service vote查看应用状态

    1. $docker stack services vote
    2. ID            NAME             MODE        REPLICAS  IMAGE
    3. 5bte3o8e0ta9  vote_result      replicated  2/2       sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_result:before
    4. h65a6zakqgq3  vote_worker      replicated  1/1       sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_worker:latest
    5. k7xzd0adhh52  vote_db          replicated  1/1       sz-pg-oam-docker-hub-001.tendcloud.com/library/postgres:9.4
    6. pvvi5qqcsnag  vote_vote        replicated  2/2       sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_vote:before
    7. z4q2gnvoxtpj  vote_redis       replicated  2/2       sz-pg-oam-docker-hub-001.tendcloud.com/library/redis:alpine
    8. zgiuxazk4ssc  vote_visualizer  replicated  1/1       sz-pg-oam-docker-hub-001.tendcloud.com/library/visualizer:stable

    使用docker stack ls和docker stack ps vote查看stack的状态

    1. $docker stack ls
    2. NAME  SERVICES
    3. vote  6
    4. $docker stack ps vote
    5. ID            NAME               IMAGE                                                                          NODE                                     DESIRED STATE  CURRENT STATE          ERROR                      PORTS
    6. tcyy62bs26sp  vote_worker.1      sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_worker:latest  sz-pg-oam-docker-test-003.tendcloud.com  Running        Running 4 minutes ago                             
    7. tfa84y1yz00j  vote_redis.1       sz-pg-oam-docker-hub-001.tendcloud.com/library/redis:alpine                    sz-pg-oam-docker-test-002.tendcloud.com  Running        Running 5 minutes ago                             
    8. 4yrp8e2pucnu  vote_visualizer.1  sz-pg-oam-docker-hub-001.tendcloud.com/library/visualizer:stable               sz-pg-oam-docker-test-001.tendcloud.com  Running        Running 5 minutes ago                             
    9. zv4dan0n9zo3  vote_worker.1      sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_worker:latest  sz-pg-oam-docker-test-003.tendcloud.com  Shutdown       Failed 4 minutes ago   "task: non-zero exit (1)"  
    10. mhbf683hiugr  vote_result.1      sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_result:before  sz-pg-oam-docker-test-001.tendcloud.com  Running        Running 5 minutes ago                             
    11. slf6je49r4v1  vote_vote.1        sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_vote:before    sz-pg-oam-docker-test-002.tendcloud.com  Running        Running 5 minutes ago                             
    12. mqypecrgriyq  vote_db.1          sz-pg-oam-docker-hub-001.tendcloud.com/library/postgres:9.4                    sz-pg-oam-docker-test-001.tendcloud.com  Running        Running 4 minutes ago                             
    13. 6n7856nsvavn  vote_redis.2       sz-pg-oam-docker-hub-001.tendcloud.com/library/redis:alpine                    sz-pg-oam-docker-test-003.tendcloud.com  Running        Running 5 minutes ago                             
    14. pcrfnm20jf0r  vote_result.2      sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_result:before  sz-pg-oam-docker-test-002.tendcloud.com  Running        Running 4 minutes ago                             
    15. ydxurw1jnft6  vote_vote.2        sz-pg-oam-docker-hub-001.tendcloud.com/library/examplevotingapp_vote:before    sz-pg-oam-docker-test-003.tendcloud.com  Running        Running 5 minutes ago

    检查

    当vote应用成功部署后，在浏览器中访问visualizer所部属到的主机的8080端口http://sz-pg-oam-docker-hub-001.tendcloud.com:8080可以看到如下画面：

    visualizer.jpg

    Visualizer用于显示服务和主机的状态。

    投票界面

    在浏览器中访问examplevotingapp_vote所部属到的主机的5000端口http://sz-pg-oam-docker-hub-001.tendcloud.com:5000可以看到如下画面：

    vote_web

    给猫投一票。cat

    结果界面

    在浏览器中访问examplevotingapp_result所部属到的主机的5001端口http://sz-pg-oam-docker-hub-001.tendcloud.com:5001可以看到如下画面.

    vote_result

    总结

    至此整个应用已经完整的部署在docker上了，并验证正常运行。

    怎么样，是用docker来部署一个应用是不是很简单？

    其实后期的维护、升级、扩展都很简单，后面会详细的说明。