How can I restore etcd cluster from snapshot in docker image on CoreOS?

[Balázs Ambrus]

Hi!

I have a Kubernetes cluster (v1.5.6) with 3 nodes etcd cluster (etcd version 3.1.5). 

This etcd nodes are running in three docker containers(on three hosts) on coreos in vmware.

I try to backup etcd with the following solution:

docker run --rm --net=host -v /tmp:/etcd_backup -e ETCDCTL_API=3 quay.io/coreos/etcd:v3.1.5 etcdctl --endpoints=[1.1.1.1:2379,2.2.2.2:2379,3.3.3.3:2379] snapshot save etcd_backup/snapshot.db

The backup has been completed succesfully.

I want to create this kubernetes cluster from zero in another vmware environment, but I need to restore etcd from snapshot for this.

So far, I have not found the right solution that works with etcd docker containers.

I try to restore with the following method, but unfortunately I did not succeed.

First, I created a new etcd node after I run the following command:

docker run --rm --net=host -v /tmp/etcd_bak:/etcd_backup -e ETCDCTL_API=3 registry:5000/quay.io/coreos/etcd:v3.1.5 etcdctl snapshot restore etcd_backup/snapshot.db --name etcd0 --initial-cluster etcd0=http://etcd0:2380,etcd1=http://etcd1:2380,etcd2=http://etcd2:2380 --initial-cluster-token etcd-cluster-1 --initial-advertise-peer-urls http://etcd0:2380

Result:

2018-06-04 09:25:52.314747 I | etcdserver/membership: added member 7ff5c9c6942f82e [http://etcd0:2380] to cluster 5d1b637f4b7740d5

2018-06-04 09:25:52.314940 I | etcdserver/membership: added member 91b417e7701c2eeb [http://etcd2:2380] to cluster 5d1b637f4b7740d5

2018-06-04 09:25:52.315096 I | etcdserver/membership: added member faeb78734ee4a93d [http://etcd1:2380] to cluster 5d1b637f4b7740d5

Unfortunately, nothing happens.

What is the good solution to restore this etcd backup?

How do I create an empty etcd cluster/node and how should I restore the snapshot?

Thank you.