The root reason of flakes, was that server was considered as ready to
early.
In particular:
```
../../bin/etcd-2456648: {"level":"info","ts":"2021-01-11T09:56:44.474+0100","caller":"rafthttp/stream.go:274","msg":"established TCP streaming connection with remote peer","stream-writer-type":"stream Message","local-member-id":"ed5f620d34a8e61b","remote-peer-id":"ca50e9357181d758"}
../../bin/etcd-2456648: {"level":"warn","ts":"2021-01-11T09:56:49.040+0100","caller":"etcdserver/server.go:1942","msg":"failed to publish local member to cluster through raft","local-member-id":"ed5f620d34a8e61b","local-member-attributes":"{Name:infra2 ClientURLs:[http://localhost:20030]}","request-path":"/0/members/ed5f620d34a8e61b/attributes","publish-timeout":"7s","error":"etcdserver: request timed out, possibly due to connection lost"}
../../bin/etcd-2456648: {"level":"info","ts":"2021-01-11T09:56:49.049+0100","caller":"etcdserver/server.go:1921","msg":"published local member to cluster through raft","local-member-id":"ed5f620d34a8e61b","local-member-attributes":"{Name:infra2 ClientURLs:[http://localhost:20030]}","request-path":"/0/members/ed5f620d34a8e61b/attributes","cluster-id":"34f27e83b3bc2ff","publish-timeout":"7s"}
```
was taking 5s. If this was happening concurrently with etcdctl, the
etcdctl could timeout.
The fix, requires servers to report 'ready to serve client requests' to consider them up.
Fixed also some whitelisted 'goroutines'.
The commit ensures that spawned etcdctl processes are "closed",
so they perform proper os wait processing.
This might have contributed to file-descriptor/open-files limit being
exceeded.
Before:
```
{"level":"info","ts":1610273495.3791487,"caller":"agent/handler.go:668","msg":"cleaning up page cache"}
{"level":"info","ts":1610273495.3793094,"caller":"agent/handler.go:94","msg":"created etcd log file","path":"/tmp/etcd-functional-2/etcd.log"}
{"level":"info","ts":1610273495.379328,"caller":"agent/handler.go:668","msg":"cleaning up page cache"}
[sudo] password for ptab:
pam_glogin: invalid password
Sorry, try again.
[sudo] password for ptab:
```
Now the caches are dropped if the current users is in sudoers, bot not
in the other cases.
To be honest I don't see the purpose for dropping the caches at all in
the test.
Old etcdserver which have not apply pr of #12165 will check auth token
even if the request is an Authenticate request.
If the client has a invalid auth token, it will not able to update it's
token, since the Authenticate has a invalid auth token.
This fix clear the auth token when encounter an ErrInvalidAuthToken to
talk with old version etcd servers.
Fix#12385 with #12165 and #12264
instead of v3.0.0-000101010000000-00000000000,
that might be misleading as we don't develop etcd v3.0.0 any longer.
This version is a virtual version and is not supposed to be tagged
within the repository. We should tag real versions like: 3.5.0-alpha.0.
Please notice that go.etcd.io/etcd/client/v2 will be versioned as `v2.305.0-pre`.
The reason is that client v2 must have v2 version. I propose a
convention to envode the major version as 100x in minor version to make
the association to the underlying repository clear, staying within v2
version family.
The change was generated using:
```
DRY_RUN=false TARGET_VERSION="v3.5.0-pre" ./scripts/release_mod.sh update_versions
```
Examplar invocations:
Edit go.mod files such that all etcd modules are pointing on given version:
```
% DRY_RUN=false TARGET_VERSION="v3.5.13" ./scripts/release_mod.sh update_versions
```
Tag latest commit with current version number for all the modules and push upstream:
```
% DRY_RUN=true REMOTE_REPO="origin" ./scripts/release_mod.sh push_mod_tags
```
* Turn off checking of format of commit message.
* scripts/fix.sh: Fix fixing whitespaces in *.sh scripts
Aparently there is a difference between:
find ./ -print0 -name *.sh and
find ./ -name *.sh -print0
* etcdserver unit tests: Do not call .Fatalf(...) from not test's goroutine.
Fixes following test failures:
https://travis-ci.com/github/etcd-io/etcd/jobs/425920416
```
% (cd server && go vet ./...)
stderr: # go.etcd.io/etcd/server/v3/etcdserver
stderr: etcdserver/server_test.go:1002:4: call to (*T).Fatalf from a non-test goroutine
stderr: etcdserver/server_test.go:1166:4: call to (*T).Fatalf from a non-test goroutine
FAIL: (code:2):
% (cd server && go vet ./...)
FAIL: 'run go vet ./...' checking failed (!=0 return code)
FAIL: 'govet' failed at Tue Nov 3 04:07:47 UTC 2020
```
