slack-19.0: fix structured logging

[timvaillancourt]

Description

This PR fixes structure logging in v19 (introduced in #449) that is not being enabled due to a bug, although we set --structured-logging on daemons

Before:

tim@Tims-MacBook-Pro vitess % git checkout slack-19.0    
Already on 'slack-19.0'
Your branch is up to date with 'origin/slack-19.0'.
tim@Tims-MacBook-Pro vitess % make NOVTADMINBUILD=1 build
Sat Oct 12 03:33:56 CEST 2024: Building source tree
tim@Tims-MacBook-Pro vitess % ./bin/vttablet --tablet-path test-123456789 --structured-logging 2>&1 | head -3
W1012 19:22:23.163333   37461 log.go:39] Failed to read in config : Config File "vtconfig" Not Found in "[/Users/tim/github/slackhq/vitess]". This is optional, and can be ignored if you are not using config files. For a detailed explanation, see https://github.com/vitessio/vitess/blob/main/doc/viper/viper.md#config-files.
W1012 19:22:23.190138   37461 http.go:57] Beginning in v20, pprof-http will default to `false`; to continue enabling pprof endpoints, please manually set this flag before upgrading.
Error: mycnf read failed: open /vt/vt_0123456789/my.cnf: no such file or directory

After w/this PR:

tim@Tims-MacBook-Pro vitess % make NOVTADMINBUILD=1 build                     
Sat Oct 12 19:20:14 CEST 2024: Building source tree
tim@Tims-MacBook-Pro vitess % ./bin/vttablet --tablet-path test-123456789 --structured-logging 2>&1 | head -3                       
W1012 19:21:23.195690   37283 log.go:39] Failed to read in config : Config File "vtconfig" Not Found in "[/Users/tim/github/slackhq/vitess]". This is optional, and can be ignored if you are not using config files. For a detailed explanation, see https://github.com/vitessio/vitess/blob/main/doc/viper/viper.md#config-files.
{"level":"info","ts":"2024-10-12T19:21:23+02:00","caller":"servenv/servenv_unix.go:66","msg":"Version: 19.0.5 (Git revision 6ba49614d7e25fbbe4fd649113a01fe7b5b13810 branch 'fix-structured-logging_slack-19.0') built on Sat Oct 12 19:20:14 CEST 2024 by tim@Tims-MacBook-Pro.local using go1.22.8 darwin/amd64"}
{"level":"warn","ts":"2024-10-12T19:21:23+02:00","caller":"servenv/http.go:57","msg":"Beginning in v20, pprof-http will default to `false`; to continue enabling pprof endpoints, please manually set this flag before upgrading."}

Related Issue(s)

• slack-19.0: add structured logging #449

Checklist

• "Backport to:" labels have been added if this change should be back-ported
• Tests were added or are not required
• Did the new or modified tests pass consistently locally and on the CI
• Documentation was added or is not required

Deployment Notes

[timvaillancourt]

Confirmed this on tablets ✅:

tvaillancourt@tablet-iad-staging-vtfun-00-80-5m9z:/var/log/vttablet$ tail vttablet.log|tail -1 |jq .
{
  "level": "warn",
  "ts": "2024-10-16T08:24:27-07:00",
  "caller": "discovery/healthcheck.go:557",
  "msg": "not marking healthy primary us_east_1e-0170333722 as Up for loadtest/80- because its PrimaryTermStartTime is smaller than the highest known timestamp from previous PRIMARYs us_east_1b-0170353516: 1728945320 < 1728945636 "
}