Use docker-compose build etcd cluster environment

Use docker-compose build etcd cluster environment

etcd is a clustered environment, micro-service architecture for managing the following configuration management functions.
A distributed, reliable key-value store for the most critical data of a distributed system.

This article is a fundamental step how to build a docker etcd cluster environment.
We use docker-compose the following etcd to build a clustered environment:

Cluster consists of three node: etcd1, etcd2, etcd3

1. Download the consul docker image

$ docker pull quay.io/coreos/etcd

2. Edit docker-compose.yaml file

$ cat docker-compose.yaml
version: '2'
networks:
byfn:

services:
etcd1:
image: quay.io/coreos/etcd
container_name: etcd1
command: etcd -name etcd1 -advertise-client-urls http://0.0.0.0:2379 -listen-client-urls http://0.0.0.0:2379 -listen-peer-urls http://0.0.0.0:2380 -initial-cluster-token etcd-cluster -initial-cluster "etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380" -initial-cluster-state new
ports:
- 2379
- 2380
networks:
- byfn

etcd2:
image: quay.io/coreos/etcd
container_name: etcd2
command: etcd -name etcd2 -advertise-client-urls http://0.0.0.0:2379 -listen-client-urls http://0.0.0.0:2379 -listen-peer-urls http://0.0.0.0:2380 -initial-cluster-token etcd-cluster -initial-cluster "etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380" -initial-cluster-state new
ports:
- 2379
- 2380
networks:
- byfn

etcd3:
image: quay.io/coreos/etcd
container_name: etcd3
command: etcd -name etcd3 -advertise-client-urls http://0.0.0.0:2379 -listen-client-urls http://0.0.0.0:2379 -listen-peer-urls http://0.0.0.0:2380 -initial-cluster-token etcd-cluster -initial-cluster "etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380" -initial-cluster-state new
ports:
- 2379
- 2380
networks:
- byfn

1. Start Service

$ docker-compose up

1. Verify the status of a cluster

Verify v2 / members node data returned from the same three values.

$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
33785a959d95 quay.io/coreos/etcd "etcd -name etcd1 ..." 2 hours ago Up 2 hours 0.0.0.0:32791->2379/tcp, 0.0.0.0:32790->2380/tcp etcd1
106ba12b1c25 quay.io/coreos/etcd "etcd -name etcd2 ..." 2 hours ago Up 2 hours 0.0.0.0:32789->2379/tcp, 0.0.0.0:32788->2380/tcp etcd2
76cd127439a3 quay.io/coreos/etcd "etcd -name etcd3 ..." 2 hours ago Up 2 hours 0.0.0.0:32787->2379/tcp, 0.0.0.0:32786->2380/tcp etcd3

$ curl -L http://127.0.0.1:32787/v2/members
{"members":[{"id":"ade526d28b1f92f7","name":"etcd1","peerURLs":["http://etcd1:2380"],"clientURLs":["http://0.0.0.0:2379"]},{"id":"bd388e7810915853","name":"etcd3","peerURLs":["http://etcd3:2380"],"clientURLs":["http://0.0.0.0:2379"]},{"id":"d282ac2ce600c1ce","name":"etcd2","peerURLs":["http://etcd2:2380"],"clientURLs":["http://0.0.0.0:2379"]}]}

$ curl -L http://127.0.0.1:32789/v2/members
{"members":[{"id":"ade526d28b1f92f7","name":"etcd1","peerURLs":["http://etcd1:2380"],"clientURLs":["http://0.0.0.0:2379"]},{"id":"bd388e7810915853","name":"etcd3","peerURLs":["http://etcd3:2380"],"clientURLs":["http://0.0.0.0:2379"]},{"id":"d282ac2ce600c1ce","name":"etcd2","peerURLs":["http://etcd2:2380"],"clientURLs":["http://0.0.0.0:2379"]}]}

$ curl -L http://127.0.0.1:32791/v2/members
{"members":[{"id":"ade526d28b1f92f7","name":"etcd1","peerURLs":["http://etcd1:2380"],"clientURLs":["http://0.0.0.0:2379"]},{"id":"bd388e7810915853","name":"etcd3","peerURLs":["http://etcd3:2380"],"clientURLs":["http://0.0.0.0:2379"]},{"id":"d282ac2ce600c1ce","name":"etcd2","peerURLs":["http://etcd2:2380"],"clientURLs":["http://0.0.0.0:2379"]}]}

You can also use the command-line tools etcdctl:

$ docker exec -t etcd1 etcdctl member list
ade526d28b1f92f7: name=etcd1 peerURLs=http://etcd1:2380 clientURLs=http://0.0.0.0:2379 isLeader=false
bd388e7810915853: name=etcd3 peerURLs=http://etcd3:2380 clientURLs=http://0.0.0.0:2379 isLeader=false
d282ac2ce600c1ce: name=etcd2 peerURLs=http://etcd2:2380 clientURLs=http://0.0.0.0:2379 isLeader=true

$ docker exec -t etcd3 etcdctl -C http://etcd1:2379,http://etcd2:2379,http://etcd3:2379 member list
ade526d28b1f92f7: name=etcd1 peerURLs=http://etcd1:2380 clientURLs=http://0.0.0.0:2379 isLeader=false
bd388e7810915853: name=etcd3 peerURLs=http://etcd3:2380 clientURLs=http://0.0.0.0:2379 isLeader=false
d282ac2ce600c1ce: name=etcd2 peerURLs=http://etcd2:2380 clientURLs=http://0.0.0.0:2379 isLeader=true

4. Use of Cluster

# 我们往一个node上上传数据，在其他node上就能下载到

curl -L http://127.0.0.1:32789/v2/keys/foo -XPUT -d value="Hello foo"
curl -L http://127.0.0.1:32789/v2/keys/foo1/foo1 -XPUT -d value="Hello foo1"
curl -L http://127.0.0.1:32789/v2/keys/foo2/foo2 -XPUT -d value="Hello foo2"
curl -L http://127.0.0.1:32789/v2/keys/foo2/foo21/foo21 -XPUT -d value="Hello foo21"

curl -L http://127.0.0.1:32787/v2/keys/foo
curl -L http://127.0.0.1:32787/v2/keys/foo2
curl -L http://127.0.0.1:32787/v2/keys/foo2?recursive=true