Etcd cluster in Docker

Quick start

# start a static etcd cluster with 3 nodes and 2 proxies
docker-compose up -d --scale etcd-node=3 --scale etcd-proxy=2
# check logs
docker-compose logs -f etcd-node
docker-compose logs -f etcd-proxy

Testing

# If using released versions earlier than v3.4, set ETCDCTL_API=3 to use v3 API.
# See https://github.com/etcd-io/etcd/tree/master/etcdctl
$ export ETCDCTL_API=3

# Use `docker network inspect docker-etcd_net_etcd` to find all containers' ip
$ ENDPOINTS=172.18.0.2:2379,172.18.0.3:2379,172.18.0.4:2379

# list cluster member
$ etcdctl --write-out=table --endpoints=$ENDPOINTS member list
+------------------+---------+-------------------------+------------------------+------------------------+
|        ID        | STATUS  |          NAME           |       PEER ADDRS       |      CLIENT ADDRS      |
+------------------+---------+-------------------------+------------------------+------------------------+
| 4861bc7f2df004f2 | started | docker-etcd_etcd-node_2 | http://172.18.0.2:2380 | http://172.18.0.2:2379 |
| d73d9d58643877a0 | started | docker-etcd_etcd-node_1 | http://172.18.0.3:2380 | http://172.18.0.3:2379 |
| e30904b276cdf79d | started | docker-etcd_etcd-node_3 | http://172.18.0.4:2380 | http://172.18.0.4:2379 |
+------------------+---------+-------------------------+------------------------+------------------------+

# check cluster status
$ etcdctl --write-out=table --endpoints=$ENDPOINTS endpoint status
+-----------------+------------------+---------+---------+-----------+-----------+------------+
|    ENDPOINT     |        ID        | VERSION | DB SIZE | IS LEADER | RAFT TERM | RAFT INDEX |
+-----------------+------------------+---------+---------+-----------+-----------+------------+
| 172.18.0.2:2379 | 402ff265b80d4dc1 |  3.3.12 |   20 kB |      true |         2 |          8 |
| 172.18.0.3:2379 | b063ce376278837c |  3.3.12 |   20 kB |     false |         2 |          8 |
| 172.18.0.4:2379 | daa53193d66b358f |  3.3.12 |   20 kB |     false |         2 |          8 |
+-----------------+------------------+---------+---------+-----------+-----------+------------+

Environment

$ cat /etc/redhat-release
CentOS Linux release 7.7.1908 (Core)

$ docker --version
Docker version 1.13.1, build 7f2769b/1.13.1

$ docker-compose --version
docker-compose version 1.24.1, build 4667896b

$ docker images --format "{{.Repository}}:{{.Tag}}"
gcr.io/etcd-development/etcd:v3.3.12

Reference

• https://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/clustering.md
• https://github.com/etcd-io/etcd/blob/master/Documentation/demo.md