Log redact on TiFlash

[JaySon-Huang]

Log redacted: Avoid printing user data (mostly user keys) to info log. Replace the value into ?.
Spec

Logs to be redacted:

• TiFlash process
  • TiKVKeyValue,RowKeyRange,HandleRange [Redact log] Redact key range and value in RSFilter from logging #1282
  • Value in RSFilter [Redact log] Redact key range and value in RSFilter from logging #1282
  • Protobuf struct in logging (not print when the logging.level is INFO)
  • Client-C resolve lock Redact the key value from error log tikv/client-c#59 Log redact for client-c #1306
• ClusterManager
• TiFlashProxy

Related issue in TiDB: pingcap/tidb#18566
Related PR in TiKV: tikv/tikv#8670

• Documents tiflash: Add TiFlash security configuration docs#4412, Add TiFlash security configuration docs-cn#5094

[solotzg]

ClusterManager only handle range of table record like [t tid _r, t tid+1 ), no user key will be printed in log.
Proxy has already contains related modify about redact-log, which could be enable with config [security] redact-info-log.

[JaySon-Huang]

For Protobuf struct in logging

Protobuf provides a class TextFormat::Printer for formatting. We can reuse some code of that class and hide the value of fields with option [need_redact = true] like this PR: pingcap/rust-protobuf#4

https://github.com/protocolbuffers/protobuf/blob/fdc35840b95f56c3aef44a3fc6ae5991f21620a5/src/google/protobuf/text_format.h#L242-L244

https://github.com/protocolbuffers/protobuf/blob/bd9a7104e11740e4bcfbde46c190c2d908ef331a/src/google/protobuf/text_format.cc#L86-L111

Related article on how to use protobuf reflection: https://zhuanlan.zhihu.com/p/313369306

[JaySon-Huang]

TODO: Update document in this URL https://docs.pingcap.com/tidb/stable/log-redaction

[JaySon-Huang]

TODO: Update document in this URL https://docs.pingcap.com/tidb/stable/log-redaction

The PRs to fix those documents:
pingcap/docs-cn#5687
pingcap/docs-cn#5688

[JaySon-Huang]

close as the Protobuf struct in logging is not print to logging because the default level is INFO