etcdctl version shows 3.5.0-pre on a 3.4/stable snap channel

[Adam Stokes]

ubuntu@ip-172-31-3-242:~$ which etcdctl
/snap/bin/etcdctl
ubuntu@ip-172-31-3-242:~$ snap list
Name Version Rev Tracking Publisher Notes
amazon-ssm-agent 2.3.714.0 1566 latest/stable/… aws✓ classic
core 16-2.44.1 8935 latest/stable canonical✓ core
core18 20200311 1705 latest/stable canonical✓ base
etcd 3.4.0 218 3.4/stable canonical✓ -

ubuntu@ip-172-31-3-242:~$ etcdctl version
etcdctl version: 3.5.0-pre
API version: 3.5

[George Kraft (cynerva)]

The etcd bin also shows version 3.5.0-pre:

$ /snap/etcd/current/bin/etcd --version
etcd Version: 3.5.0-pre
Git SHA: Not provided (use ./build instead of go build)
Go Version: go1.12.9
Go OS/Arch: linux/amd64

[Tim Van Steenburgh (tvansteenburgh)]

This is fixed in 3.4/edge. I added a version check to the test script that gets run by the GH Action (https://github.com/juju-solutions/etcd-snaps/runs/634252063).

Once the arm64 build finishes I suggest we push this new build (version 3.4.5) all the way through stable on the 3.4 track. I think this is fine since the default track in Charmed Kubernetes 1.18 is 3.3.

[Tim Van Steenburgh (tvansteenburgh)]

3.4.5 has been promoted through stable on the 3.4 track.

[Gary.Wang (gary-wzl77)]

Just a sidenote on this fix: these changes broke our current Anb0x Cloud deployment.
Our etcd charm is following 3.4/channel. Prior to this fix, the version `3.5.0-pre` was installed from etcd charm somehow by mistaken, after the new 3.4.5 was promoted to the store, the etcd snap got *upgraded* automatically by snapd from `3.5.0-pre` to `3.4.5`. However the downgrading is not feasbile from etcd:

```
        May 18 08:52:58 ip-172-31-35-44 etcd[23834]: cluster cannot be downgraded (current version: 3.4.5 is lower than determined cluster version: 3.5).
        May 18 08:52:58 ip-172-31-35-44 systemd[1]: snap.etcd.etcd.service: Main process exited, code=exited, status=1/FAILURE
```

as an immediate step, we now have to revert this etcd snap to the previous working verison.