etcd/tests/framework
Piotr Tabor d57f8dba62 Deflaking: Make WaitLeader (and WaitMembersForLeader) aggressively (30s) wait for leader being established.
Nearly none of the tests was checking the value... just assuming WaitLeader success.

```
    maintenance_test.go:277: Waiting for leader...
    logger.go:130: 2022-04-03T08:01:09.914+0200	INFO	m0	cluster version differs from storage version.	{"member": "m0", "cluster-version": "3.6.0", "storage-version": "3.5.0"}
    logger.go:130: 2022-04-03T08:01:09.915+0200	WARN	m0	leader failed to send out heartbeat on time; took too long, leader is overloaded likely from slow disk	{"member": "m0", "to": "2acc3d3b521981", "heartbeat-interval": "10ms", "expected-duration": "20ms", "exceeded-duration": "103.756219ms"}
    logger.go:130: 2022-04-03T08:01:09.916+0200	INFO	m0	updated storage version	{"member": "m0", "new-storage-version": "3.6.0"}
    ...
    logger.go:130: 2022-04-03T08:01:09.926+0200	INFO	grpc	[[roundrobin] roundrobinPicker: Build called with info: {map[0xc002630ac0:{{unix:localhost:m0 localhost <nil> 0 <nil>}} 0xc002630af0:{{unix:localhost:m1 localhost <nil> 0 <nil>}} 0xc002630b20:{{unix:localhost:m2 localhost <nil> 0 <nil>}}]}]
    logger.go:130: 2022-04-03T08:01:09.926+0200	WARN	m0	apply request took too long	{"member": "m0", "took": "114.661766ms", "expected-duration": "100ms", "prefix": "", "request": "header:<ID:12658633312866157316 > cluster_version_set:<ver:\"3.6.0\" > ", "response": ""}
    logger.go:130: 2022-04-03T08:01:09.927+0200	INFO	m0	cluster version is updated	{"member": "m0", "cluster-version": "3.6"}
    logger.go:130: 2022-04-03T08:01:09.955+0200	INFO	m2.raft	9f96af25a04e2ec3 [logterm: 2, index: 8, vote: 9903a56eaf96afac] ignored MsgVote from 2acc3d3b521981 [logterm: 2, index: 8] at term 2: lease is not expired (remaining ticks: 10)	{"member": "m2"}
    logger.go:130: 2022-04-03T08:01:09.955+0200	INFO	m0.raft	9903a56eaf96afac [logterm: 2, index: 8, vote: 9903a56eaf96afac] ignored MsgVote from 2acc3d3b521981 [logterm: 2, index: 8] at term 2: lease is not expired (remaining ticks: 5)	{"member": "m0"}
    logger.go:130: 2022-04-03T08:01:09.955+0200	INFO	m0.raft	9903a56eaf96afac [term: 2] received a MsgAppResp message with higher term from 2acc3d3b521981 [term: 3]	{"member": "m0"}
    logger.go:130: 2022-04-03T08:01:09.955+0200	INFO	m0.raft	9903a56eaf96afac became follower at term 3	{"member": "m0"}
    logger.go:130: 2022-04-03T08:01:09.955+0200	INFO	m0.raft	raft.node: 9903a56eaf96afac lost leader 9903a56eaf96afac at term 3	{"member": "m0"}
    maintenance_test.go:279: Leader established.
```

Tmp
2022-04-03 12:23:09 +02:00
..