docker 容器入门（五）

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写在前面的话

每篇一句

学如逆水行舟，不进则退。心似平原跑马，易放难收。

持久化docker数据

上篇通过docker-compose.yml + swarms 构建了testapp web服务,今天我们来持久化数据，通过redis记录web 已访问过的数量。
由于笔记本电脑换地方连wifi了，虚拟机ip变了（dhcp获取的）
centos7 :192.168.2.104
ubuntu :192.168.2.102

前置环境准备，清理

开启2台虚拟机后，发现swarm集群ubuntu 节点没有连接上，是因为ip变了。testapp还是保持5个节点（容器）都运行在centos7上。

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[root@localhost ~]# docker node ls
ID                            HOSTNAME                STATUS              AVAILABILITY        MANAGER STATUS
gtb0ip6zpu4hazqg4bgp5z19m     ubuntu                  Down                Active              
qmjxu1mlwksrxfwyq1sgcerrw *   localhost.localdomain   Ready               Active              Leader
[root@localhost ~]# docker ps
CONTAINER ID        IMAGE                              COMMAND             CREATED             STATUS              PORTS               NAMES
9163c5a14c46        zakizqzhang/get-started:20171028   "python app.py"     11 minutes ago      Up 11 minutes       80/tcp              testapp_web.1.mn37pcrl4qdapvocnzdkbf5fb
f2d05226f3c4        zakizqzhang/get-started:20171028   "python app.py"     11 minutes ago      Up 11 minutes       80/tcp              testapp_web.4.z0djkare7lccee71repnd895n
c0c549d6c746        zakizqzhang/get-started:20171028   "python app.py"     11 minutes ago      Up 11 minutes       80/tcp              testapp_web.2.0rfc20le7umx8kxycb8tk0xwm
36b81da1dd06        zakizqzhang/get-started:20171028   "python app.py"     11 minutes ago      Up 11 minutes       80/tcp              testapp_web.3.pmgnd8dot1o2vi5minpd3awqh
f96819397bbc        zakizqzhang/get-started:20171028   "python app.py"     11 minutes ago      Up 11 minutes       80/tcp              testapp_web.5.uwgl3onvcav65rjgv7q3rzkdm

清理步骤

删除testapp应用
centos7

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[root@localhost ~]# docker stack rm  testapp 
Removing service testapp_web
Removing network testapp_webnet
[root@localhost ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

删除swarm节点后清理swarm
centos7

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[root@localhost ~]# docker node ls
ID                            HOSTNAME                STATUS              AVAILABILITY        MANAGER STATUS
gtb0ip6zpu4hazqg4bgp5z19m     ubuntu                  Down                Active              
qmjxu1mlwksrxfwyq1sgcerrw *   localhost.localdomain   Ready               Active              Leader
[root@localhost ~]# docker node rm  gtb0ip6zpu4hazqg4bgp5z19m
gtb0ip6zpu4hazqg4bgp5z19m
[root@localhost ~]# docker node rm qmjxu1mlwksrxfwyq1sgcerrw
Error response from daemon: rpc error: code = 9 desc = node qmjxu1mlwksrxfwyq1sgcerrw is a cluster manager and is a member of the raft cluster. It must be demoted to worker before removal
[root@localhost ~]# docker node  ls
ID                            HOSTNAME                STATUS              AVAILABILITY        MANAGER STATUS
qmjxu1mlwksrxfwyq1sgcerrw *   localhost.localdomain   Ready               Active              Leader
[root@localhost ~]# docker swarm  leave  --force
Node left the swarm.
[root@localhost ~]# docker node ls
Error response from daemon: This node is not a swarm manager. Use "docker swarm init" or "docker swarm join" to connect this node to swarm and try again.

ubuntu

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root@ubuntu:~# docker swarm leave 
Node left the swarm.

重新初始化swarm集群

centos 7

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[root@localhost ~]# docker swarm  init
Swarm initialized: current node (jkkb3lg7o5x1oel28wtyeu1b3) is now a manager.
To add a worker to this swarm, run the following command:
    docker swarm join --token SWMTKN-1-3msmax4yocfing9j7cb7ls2ns6d24femvlr6x1lhekc2ee9wn3-a63thuor7e94589s4rh4vt667 192.168.2.104:2377
To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.
[root@localhost ~]# docker node  ls
ID                            HOSTNAME                STATUS              AVAILABILITY        MANAGER STATUS
bl0domocxtrmcvch2mscnulhy     ubuntu                  Ready               Active              
jkkb3lg7o5x1oel28wtyeu1b3 *   localhost.localdomain   Ready               Active              Leader

ubuntu

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root@ubuntu:~# docker swarm join --token SWMTKN-1-3msmax4yocfing9j7cb7ls2ns6d24femvlr6x1lhekc2ee9wn3-a63thuor7e94589s4rh4vt667 192.168.2.104:2377
This node joined a swarm as a worker.

增加visualizer服务

更新docker-compose.yml

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version: "3"
services:
  web:
    # replace username/repo:tag with your name and image details
    image: zakizqzhang/get-started:20171028
    deploy:
      replicas: 5
      restart_policy:
        condition: on-failure
      resources:
        limits:
          cpus: "0.1"
          memory: 50M
    ports:
      - "80:80"
    networks:
      - webnet
  visualizer:
    image: dockersamples/visualizer:stable
    ports:
      - "8080:8080"
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock"
    deploy:
      placement:
        constraints: [node.role == manager]
    networks:
      - webnet
networks:
  webnet:

部署运行

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[root@localhost docker]# docker stack deploy -c docker-compose.yml testappv2
Creating network testappv2_webnet
Creating service testappv2_visualizer
Creating service testappv2_web
[root@localhost docker]# docker ps
CONTAINER ID        IMAGE                              COMMAND             CREATED              STATUS              PORTS               NAMES
80fd4a609479        dockersamples/visualizer:stable    "npm start"         About a minute ago   Up About a minute   8080/tcp            testappv2_visualizer.1.3is8k7vyiapxpezpzyc46y66q
a75752bb6504        zakizqzhang/get-started:20171028   "python app.py"     About a minute ago   Up About a minute   80/tcp              testappv2_web.1.xxykn8aa5n8l2kzdijzlgdw96
2fb39081b542        zakizqzhang/get-started:20171028   "python app.py"     About a minute ago   Up About a minute   80/tcp              testappv2_web.3.lodsgr7aic4aj0dr8i6ofyjkf


可以明确看到cento7上运行了2个web,1个visualizer容器；ubunut上运行了3个web容器

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[root@localhost docker]# docker stack  ps testappv2
ID                  NAME                     IMAGE                              NODE                    DESIRED STATE       CURRENT STATE           ERROR               PORTS
xxykn8aa5n8l        testappv2_web.1          zakizqzhang/get-started:20171028   localhost.localdomain   Running             Running 6 minutes ago                       
3is8k7vyiapx        testappv2_visualizer.1   dockersamples/visualizer:stable    localhost.localdomain   Running             Running 6 minutes ago                       
uk75cr884jr4        testappv2_web.2          zakizqzhang/get-started:20171028   ubuntu                  Running             Running 6 minutes ago                       
lodsgr7aic4a        testappv2_web.3          zakizqzhang/get-started:20171028   localhost.localdomain   Running             Running 6 minutes ago                       
26nxthxl9f77        testappv2_web.4          zakizqzhang/get-started:20171028   ubuntu                  Running             Running 6 minutes ago                       
j1t2qiu5g046        testappv2_web.5          zakizqzhang/get-started:20171028   ubuntu                  Running             Running 6 minutes ago

数据持久化,增加redis服务记录访客数量

更新docker-compose.yml

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[root@localhost docker]# cat docker-compose.yml
version: "3"
services:
  web:
    # replace username/repo:tag with your name and image details
    image: zakizqzhang/get-started:20171028
    deploy:
      replicas: 5
      restart_policy:
        condition: on-failure
      resources:
        limits:
          cpus: "0.1"
          memory: 50M
    ports:
      - "80:80"
    networks:
      - webnet
  visualizer:
    image: dockersamples/visualizer:stable
    ports:
      - "8080:8080"
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock"
    deploy:
      placement:
        constraints: [node.role == manager]
    networks:
      - webnet
  redis:
    image: redis
    ports:
      - "6379:6379"
    volumes:
      - /home/docker/data:/data
    deploy:
      placement:
        constraints: [node.role == manager]
    command: redis-server --appendonly yes
    networks:
      - webnet
networks:
  webnet:

建目录用于存放redis数据,再部署应用

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[root@localhost docker]# mkdir   -p  /home/docker/data
[root@localhost docker]# docker stack deploy -c docker-compose.yml testappv3
Creating network testappv3_webnet
Creating service testappv3_redis
Creating service testappv3_web
Creating service testappv3_visualizer


登录redis容器看看和本地是否一致

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[root@localhost data]# docker ps
CONTAINER ID        IMAGE                              COMMAND                  CREATED             STATUS              PORTS               NAMES
386bbd476d31        dockersamples/visualizer:stable    "npm start"              2 minutes ago       Up 2 minutes        8080/tcp            testappv3_visualizer.1.kfm592mrtksanhyr4nl2jozam
3b8ef34422a9        zakizqzhang/get-started:20171028   "python app.py"          2 minutes ago       Up 2 minutes        80/tcp              testappv3_web.5.v3wdlxmyrb83ula8mzwhi38tz
1ec62591ee51        zakizqzhang/get-started:20171028   "python app.py"          2 minutes ago       Up 2 minutes        80/tcp              testappv3_web.2.kycjsxycbq7rxv14sn4zkkvru
4fab48a2c61d        redis:latest                       "docker-entrypoint..."   3 minutes ago       Up 3 minutes        6379/tcp            testappv3_redis.1.mdx6ce4zef7a2vt9zey3o95te
[root@localhost ~]# docker exec -it  4fab48a2c61d  bash
root@4fab48a2c61d:/data# ls -l
total 4
-rw-r--r-- 1 redis redis 527 Nov  6 14:08 appendonly.aof
root@4fab48a2c61d:/data# du -sh appendonly.aof 
4.0K	appendonly.aof
root@4fab48a2c61d:/data# redis-cli 
127.0.0.1:6379> ping
PONG
127.0.0.1:6379> config get dir
1) "dir"
2) "/data"
127.0.0.1:6379> keys *
1) "counter"
127.0.0.1:6379> get counter
"14"
127.0.0.1:6379>

本地查看验证redis容器/data的数据存放在host /home/docker/data/ 目录。

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[root@localhost ~]# cd /home/docker/data/
[root@localhost data]# pwd
/home/docker/data
[root@localhost data]# ls -l
总用量 4
-rw-r--r-- 1 systemd-bus-proxy ssh_keys 527 11月  6 22:08 appendonly.aof
[root@localhost data]# du -sh appendonly.aof 
4.0K	appendonly.aof

----纸上得来终觉浅绝知此事要躬行----
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