docker compose Implementation Steps for Deploying etcd Cluster

  • 2021-11-10 11:17:51
  • OfStack

Directory writing docker-compose. yml Run docker-compose Check the build status Test node Simple interaction between Golang and etcd

Write docker-compose. yml


version: "3.0"

networks:
  etcd-net:           #  Network 
    driver: bridge    #  Bridging mode 

volumes:
  etcd1_data:         #  The name of the data volume mounted locally 
    driver: local
  etcd2_data:
    driver: local
  etcd3_data:
    driver: local
###
### etcd  For other environment configurations, see: https://doczhcn.gitbook.io/etcd/index/index-1/configuration
###
services:
  etcd1:
    image: bitnami/etcd:latest  #  Mirror image 
    container_name: etcd1       #  Container name  --name
    restart: always             #  Always restart 
    networks:
      - etcd-net                #  Network used  --network
    ports:                      #  Port mapping  -p
      - "20000:2379"
      - "20001:2380"
    environment:                #  Environment variable  --env
      - ALLOW_NONE_AUTHENTICATION=yes                       #  Allow login without password 
      - ETCD_NAME=etcd1                                     # etcd  The name of 
      - ETCD_INITIAL_ADVERTISE_PEER_URLS=http://etcd1:2380  #  List the partners of this member  URL  So that it can be notified to other members of the cluster 
      - ETCD_LISTEN_PEER_URLS=http://0.0.0.0:2380           #  Used to monitor partner communication URL List 
      - ETCD_LISTEN_CLIENT_URLS=http://0.0.0.0:2379         #  Used to listen for client traffic URL List 
      - ETCD_ADVERTISE_CLIENT_URLS=http://etcd1:2379        #  List the clients for this member URL That notifies other members of the cluster 
      - ETCD_INITIAL_CLUSTER_TOKEN=etcd-cluster             #  Used during startup  etcd  Initialization cluster token of cluster 
      - ETCD_INITIAL_CLUSTER=etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380 #  Initialize cluster configuration for startup 
      - ETCD_INITIAL_CLUSTER_STATE=new                      #  Initialize cluster state 
    volumes:
      - etcd1_data:/bitnami/etcd                            #  Mounted data volume 

  etcd2:
    image: bitnami/etcd:latest
    container_name: etcd2
    restart: always
    networks:
      - etcd-net
    ports:
      - "20002:2379"
      - "20003:2380"
    environment:
      - ALLOW_NONE_AUTHENTICATION=yes
      - ETCD_NAME=etcd2
      - ETCD_INITIAL_ADVERTISE_PEER_URLS=http://etcd2:2380
      - ETCD_LISTEN_PEER_URLS=http://0.0.0.0:2380
      - ETCD_LISTEN_CLIENT_URLS=http://0.0.0.0:2379
      - ETCD_ADVERTISE_CLIENT_URLS=http://etcd2:2379
      - ETCD_INITIAL_CLUSTER_TOKEN=etcd-cluster
      - ETCD_INITIAL_CLUSTER=etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380
      - ETCD_INITIAL_CLUSTER_STATE=new
    volumes:
      - etcd2_data:/bitnami/etcd

  etcd3:
    image: bitnami/etcd:latest
    container_name: etcd3
    restart: always
    networks:
      - etcd-net
    ports:
      - "20004:2379"
      - "20005:2380"
    environment:
      - ALLOW_NONE_AUTHENTICATION=yes
      - ETCD_NAME=etcd3
      - ETCD_INITIAL_ADVERTISE_PEER_URLS=http://etcd3:2380
      - ETCD_LISTEN_PEER_URLS=http://0.0.0.0:2380
      - ETCD_LISTEN_CLIENT_URLS=http://0.0.0.0:2379
      - ETCD_ADVERTISE_CLIENT_URLS=http://etcd3:2379
      - ETCD_INITIAL_CLUSTER_TOKEN=etcd-cluster
      - ETCD_INITIAL_CLUSTER=etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380
      - ETCD_INITIAL_CLUSTER_STATE=new
    volumes:
      - etcd3_data:/bitnami/etcd

Run docker-compose


[root@centos8 etcdtest]# tree
.
 Off-  docker-compose.yml

0 directories, 1 file
[root@centos8 etcdtest]# docker-compose up -d
[+] Running 4/4
 ⠿ Network etcdtest_etcd-net  Created                                                                                                                                 0.1s
 ⠿ Container etcd3            Started                                                                                                                                 0.6s
 ⠿ Container etcd1            Started                                                                                                                                 0.7s
 ⠿ Container etcd2            Started                                                                                                                                 0.7s
[root@centos8 etcdtest]# 

Check the build status

View node startup


[root@centos8 etcdtest]# docker ps
CONTAINER ID   IMAGE                 COMMAND                  CREATED          STATUS          PORTS                                                                                      NAMES
89469f98491f   bitnami/etcd:latest   "/opt/bitnami/script … "   54 seconds ago   Up 53 seconds   0.0.0.0:20004->2379/tcp, :::20004->2379/tcp, 0.0.0.0:20005->2380/tcp, :::20005->2380/tcp   etcd3
5454f5a719a2   bitnami/etcd:latest   "/opt/bitnami/script … "   54 seconds ago   Up 53 seconds   0.0.0.0:20000->2379/tcp, :::20000->2379/tcp, 0.0.0.0:20001->2380/tcp, :::20001->2380/tcp   etcd1
bf989f9512b5   bitnami/etcd:latest   "/opt/bitnami/script … "   54 seconds ago   Up 53 seconds   0.0.0.0:20002->2379/tcp, :::20002->2379/tcp, 0.0.0.0:20003->2380/tcp, :::20003->2380/tcp   etcd2

View mounted data volumes


[root@centos8 etcdtest]# docker volume ls
DRIVER    VOLUME NAME
local     etcdtest_etcd1_data
local     etcdtest_etcd2_data
local     etcdtest_etcd3_data

[root@centos8 etcdtest]# docker inspect etcd1 

"Mounts": [
    {
        "Type": "volume",
        "Name": "etcdtest_etcd1_data",
        "Source": "/var/lib/docker/volumes/etcdtest_etcd1_data/_data",
        "Destination": "/bitnami/etcd",
        "Driver": "local",
        "Mode": "z",
        "RW": true,
        "Propagation": ""
    }
]

Test node

Write 1 key from etcd1


[root@centos8 etcdtest]# docker exec -it etcd1 bash
I have no name!@5454f5a719a2:/opt/bitnami/etcd$ etcdctl put name "i am wxf"
OK

Read 1 value from etcd2


[wxf@centos8 ~]$ docker exec -it etcd2 bash
I have no name!@bf989f9512b5:/opt/bitnami/etcd$ etcdctl get name
name
i am wxf

Successful construction!

Simple interaction between Golang and etcd


package main

import (
 "context"
 "fmt"
 "go.etcd.io/etcd/client/v3"
 "time"
)

func main() {
 cli, err := clientv3.New(clientv3.Config{
  Endpoints:   []string{"http://192.168.135.10:20000", "http://192.168.135.10:20002", "http://192.168.135.10:20004"},
  DialTimeout: 5 * time.Second,
 })
 if err != nil {
  fmt.Printf("connect to etcd failed, err:%v\n", err)
  return
 }
 defer cli.Close()
 fmt.Println("connect to etcd success")
 defer cli.Close()

 go Watch(cli)

 Create(cli)
 Read(cli)
 Delete(cli)
 Update(cli)
 select {}
}

func Watch(cli *clientv3.Client) {
 rch := cli.Watch(context.Background(), "name") // type WatchChan <-chan WatchResponse
 for wresp := range rch {
  for _, ev := range wresp.Events {
   fmt.Printf("Type: %s Key:%s Value:%s\n", ev.Type, ev.Kv.Key, ev.Kv.Value)
  }
 }
 fmt.Println("out")
}

func Create(cli *clientv3.Client) {
 // put
 ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
 _, err := cli.Put(ctx, "name", "wxf")
 cancel()
 if err != nil {
  fmt.Printf("put to etcd failed, err:%v\n", err)
  return
 }
}

func Read(cli *clientv3.Client) {
 //get
 ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
 resp, err := cli.Get(ctx, "name")
 cancel()
 if err != nil {
  fmt.Printf("get from etcd failed, err:%v\n", err)
  return
 }
 for _, ev := range resp.Kvs {
  fmt.Printf("Type: %s Key:%s Value:%s\n", "READ", ev.Key, ev.Value)
 }
}

func Update(cli *clientv3.Client) {
 // put
 ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
 _, err := cli.Put(ctx, "name", "xyy")
 cancel()
 if err != nil {
  fmt.Printf("put to etcd failed, err:%v\n", err)
  return
 }
}

func Delete(cli *clientv3.Client) {
 //del
 ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
 _, err := cli.Delete(ctx, "name")
 cancel()
 if err != nil {
  fmt.Printf("delete from etcd failed, err:%v\n", err)
  return
 }
}

go run main.go

connect to etcd success
Type: PUT Key:name Value:wxf
Type: READ Key:name Value:wxf
Type: DELETE Key:name Value:
Type: PUT Key:name Value:xyy
Type: PUT Key:name Value:test for terminal
Type: PUT Key:name Value:test for terminal aabbccdd

I have no name!@5454f5a719a2:/opt/bitnami/etcd$ etcdctl put name "test for terminal"
OK
I have no name!@5454f5a719a2:/opt/bitnami/etcd$ etcdctl put name "test for terminal aabbccdd"
OK


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