$ docker compose pull
[+] Running 3/3
 ⠿ etcd-3 Pulled                                                       3.9s
 ⠿ etcd-1 Pulled                                                       3.9s
 ⠿ etcd-2 Pulled                                                       3.9s

$ docker compose up -d
[+] Running 7/7
 ⠿ Network etcd-cluster_default     Created                            0.1s
 ⠿ Volume "etcd-cluster_etcd3"      Created                            0.0s
 ⠿ Volume "etcd-cluster_etcd1"      Created                            0.0s
 ⠿ Volume "etcd-cluster_etcd2"      Created                            0.0s
 ⠿ Container etcd-cluster-etcd-2-1  Started                            0.9s
 ⠿ Container etcd-cluster-etcd-3-1  Started                            1.1s
 ⠿ Container etcd-cluster-etcd-1-1  Started                            1.1s

$ docker exec -it etcd-cluster-etcd-1-1 etcdctl endpoint health
127.0.0.1:2379 is healthy: successfully committed proposal: took = 2.560575ms

$ docker exec -it etcd-cluster-etcd-2-1 etcdctl endpoint health
127.0.0.1:2379 is healthy: successfully committed proposal: took = 2.622971ms

$ docker exec -it etcd-cluster-etcd-3-1 etcdctl endpoint health
127.0.0.1:2379 is healthy: successfully committed proposal: took = 2.561252ms

# put secret from any one of the etcd container
$ docker exec -it etcd-cluster-etcd-1-1 etcdctl put secret password
OK

$ docker exec -it etcd-cluster-etcd-1-1 etcdctl get secret
secret
password

$ docker exec -it etcd-cluster-etcd-2-1 etcdctl get secret
secret
password

$ docker exec -it etcd-cluster-etcd-3-1 etcdctl get secret
secret
password