[release-3.5] Add e2e test to verify etcd is able to automatically fix the issue

[ahrtr]

caused by #19557

Please read https://github.com/etcd-io/etcd/blob/main/CONTRIBUTING.md#contribution-flow.

[ahrtr]

Link to

• [release-3.5] Learner promotion isn't persisted to v3store (bbolt) #19557
• [release-3.5] [Solution 2] Auto sync members in v3store if Islearner is the only field that differs between v2store and v3store #19606

[fuweid]

LGTM

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ahrtr, fuweid

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [ahrtr]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[fuweid]

ping @serathius @siyuanfoundation

We don't need further code change. ETCD server always publishes member's attributes during starting. This update is updated through RAFT. In v3.5 release, member information is from v2 store, which is always valid and correctness. For the UpdateAttributes, it gets member info from v2 store data, updates attributes and then applies it into backend. Since this raft log index is higher than applied in v3 backend, so UpdateAttributes always applies change into v3 backend.

etcd/server/etcdserver/api/membership/cluster.go

Lines 491 to 503 in 3c65dfa

	func (c *RaftCluster) UpdateAttributes(id types.ID, attr Attributes, shouldApplyV3 ShouldApplyV3) {
	c.Lock()
	defer c.Unlock()
	if m, ok := c.members[id]; ok {
	m.Attributes = attr
	if c.v2store != nil {
	mustUpdateMemberAttrInStore(c.lg, c.v2store, m)
	}
	if c.be != nil && shouldApplyV3 {
	unsafeSaveMemberToBackend(c.lg, c.be, m)
	}
	return

Since we already allows ETCD to override existing member information, this publish call will help us do migration. So we don't need code change. Just add e2e test to ensure that.

[siyuanfoundation]

/lgtm

[ahrtr]

@ivanvc we are ready to release 3.5.20