Docker 學習筆記 `docker-compose.yml`

8 min readOct 28, 2019

version: "3"
services:
  web:  # service 的名稱
    image: username/repo:tag
    deploy:
      replicas: 5  # 從這個image開5個instance
      resources:   # 每一個最多只能用10%的CPU / 50MB的ram
        limits:
          cpus: "0.1"
          memory: 50M
      restart_policy: 
        condition: on-failure ＃只要有一個掛點就重開container
    ports:
      - "4000:80"  # 機器上的4000 port對應到 container內的 80 port
    networks:
      - webnet #指定 web service上所有的containers經由 負載平衡的 webnet 網路共享他們的 80 port
networks:
  webnet: ＃定義webnet網路為預設設定

swarm初始化：docker swarm init

$ docker swarm init
Swarm initialized: current node (bhl4roewyiczl6jsc0n3ha5jl) is now a manager.....

部屬Service docker stack deploy -c docker-compose.yml <app名稱>

$ docker stack deploy -c docker-compose.yml getstartedlab
Creating network getstartedlab_webnet
Creating service getstartedlab_web

檢視Service清單：docker service ls

$ docker service ls
ID                  NAME                MODE                REPLICAS            IMAGE                                  PORTS
j6qm5xjrtx42        getstartedlab_web   replicated          5/5                 jessie75919/docker-get-started:part2   *:4000->80/tcp

name ＝ <app名稱>_<service名稱> => getstartedlab_web

檢視 Service內的執行的container :

docker service ps<app名稱>_<service名稱>

$ docker service ps getstartedlab_web
ID                  NAME                  IMAGE                                  NODE                    DESIRED STATE       CURRENT STATE                ERROR               PORTS
ob9thyo6xpb5        getstartedlab_web.1   jessie75919/docker-get-started:part2   linuxkit-025000000001   Running             Running about a minute ago
81c69xhoahgt        getstartedlab_web.2   jessie75919/docker-get-started:part2   linuxkit-025000000001   Running             Running about a minute ago
qvlc8lvshzjg        getstartedlab_web.3   jessie75919/docker-get-started:part2   linuxkit-025000000001   Running             Running about a minute ago
28s0g73rb6st        getstartedlab_web.4   jessie75919/docker-get-started:part2   linuxkit-025000000001   Running             Running about a minute ago
lp68wxvdyq9o        getstartedlab_web.5   jessie75919/docker-get-started:part2   linuxkit-025000000001   Running             Running about a minute ago

單一個container在一個service被稱為 task ，每一個task都有一個獨立的ID

到 localhost:4000查看是否成功的運行起來。

關閉 app stack: docker stack rm <app名稱>

$ docker stack rm getstartedlab
Removing service getstartedlab_web
Removing network getstartedlab_webnet

關閉 swarm: docker swarm leave --force

$ docker swarm leave --force
Node left the swarm.

# Swarm

Enable Swarm mode => 把目前這台主機設定為 swarm manager

docker swarm init

設定為workers => docker swarm join

新開兩台virtualbox 上的虛擬機

docker-machine create --driver virtualbox myvm1 # swarm manager
docker-machine create --driver virtualbox myvm2 # worker

檢視一下目前虛擬機的狀態：

$ docker-machine ls
NAME    ACTIVE   DRIVER       STATE     URL                         SWARM   DOCKER     ERRORS
myvm1   -        virtualbox   Running   tcp://192.168.99.101:2376           v18.09.1
myvm2   -        virtualbox   Running   tcp://192.168.99.102:2376           v18.09.1

指定第一台vm為 swarm manager

$ docker-machine ssh myvm1 "docker swarm init --advertise-addr <myvm1 ip>"

$ docker-machine ssh myvm1 "docker swarm init --advertise-addr 192.168.99.101:2377"
Swarm initialized: current node (jopdxt6599vcmyouali4y1w6h) is now a manager.

指定第二台vm為 worker

docker-machine ssh myvm2 "docker swarm join --token <token >192.168.99.101:2377"

查看目前所有的vm1管理的所有node:

docker-machine ssh myvm1 "docker node ls"

$ docker-machine ssh myvm1 "docker node ls"
ID                            HOSTNAME            STATUS              AVAILABILITY        MANAGER STATUS      ENGINE VERSION
jopdxt6599vcmyouali4y1w6h *   myvm1               Ready               Active              Leader              18.09.1
tzf6jtdpu7z16v9ousjeddx3k     myvm2               Ready               Active                                  18.09.1

任一 worker node 離開 swarm docker swarm leave