Remove global logging functions in libbeat

[urso]

In order to better support structured logging, we want to get rid of the global logger functions. The API of the global logger functions is not in line with the methods defined by (*logp).Logger.

For now we will focus on libbeat first.

Refactoring Notes/Tips:

• replace logp.Debug/Info/Warn/... with f variants like (*Logger).Debugf/Infof/Warnf/... if a format string has been used. Otherwise stick with (*Logger).Debug/Info/...
• Use %+v when logging an error using a format string. Some logger libraries implement fmt.Formatter and will print the wrapped error only if + is given.
• logp.Debug accepts as first argument the selector name. *logp.Logger instances have a name and the selector name must be removed when switching to (*Logger).Debugf
• use (*Logger).Named (prefer (*Logger).Named) to create a logger instance in order to replace logp.MakeDebug. For now in unit tests you can use logp.L() if you need to pass a logger you don't care about
• use logp.NewLogger to reduce the amount of transitive changes. NewLogger will be removed in the future as well, but for now it can help to reduce PR sizes.
• store/pass logger instances locally. Do not store logger instances in private package global variables.
• Use the compiler:
  • use tags=nologpglobal to compile/test a package without logp global logging functions being available
  • Do dependend packages still build?
• Consider error values.
  • If we log a message without context and return an error value to be logged with a similar message, consider to just return the error value
  • If we log a message, but return the original error consider to remove the log message and wrap the error using an appropriate error message.

Tasks

• [x] Add nologpglobal build tag to logp elastic/beats#15700
• [ ] libbeat cleanups:
  • [ ] libbeat/autodiscover
  • [ ] appenders/config
  • [ ] builder
  • [x] providers
    • [x] docker elastic/beats#16003
    • [x] kubernetes elastic/beats#16003
    • [x] jolokia elastic/beats#16003
  • [ ] template
  • [ ] libbeat/cfgfile
  • [ ] libbeat/cloudid elastic/beats#18500
  • [ ] libbeat/cmd/instance
  • [x] libbeat/common/bus elastic/beats#16003
  • [ ] libbeat/common/config.go
  • [x] libbeat/common/docker elastic/beats#16003
  • [ ] libbeat/common/event.go elastic/beats#16149
  • [x] libbeat/common/fmtstr elastic/beats#15943
  • [x] libbeat/common/kubernetes elastic/beats#16003
  • [x] libbeat/common/jsontransform elastic/beats#18550
  • [ ] libbeat/common/safemapstr
  • [ ] libbeat/common/schema
  • [ ] libbeat/common/schema/mapstriface
  • [x] libbeat/common/streambuf elastic/beats#15945
  • [x] libbeat/common/transport/tlscommon (https://github.com/elastic/beats/pull/16761)
  • [ ] libbeat/dashboards
  • [x] libbeat/keystore elastic/beats#15946
  • [ ] libbeat/kibana elastic/beats#18258
  • [ ] libbeat/metric/system
  • [ ] memory elastic/beats#18500
  • [ ] process elastic/beats#18500
  • [x] libbeat/mock https://github.com/elastic/beats/pull/18552
  • [x] libbeat/monitoring/ (https://github.com/elastic/beats/pull/16761)
  • [x] adapter
  • [x] report/elasticsearch
  • [x] libbeat/outputs (https://github.com/elastic/beats/pull/16761)
  • [x] libbeat/outputs/console
  • [x] libbeat/outputs/elasticsearch
  • [x] libbeat/outputs/fileout
  • [x] libbeat/outputs/kafka
  • [x] libbeat/outputs/logstash
  • [x] libbeat/outputs/outil
  • [x] libbeat/outputs/redis
  • [x] libbeat/outputs/transport
  • [x] libbeat/plugin https://github.com/elastic/beats/pull/18552
  • [ ] libbeat/processors/
  • [x] actions elastic/beats#16654
  • [x] add_cloud_metadata elastic/beats#16654
  • [x] add_host_metadata elastic/beats#16654
  • [x] add_docker_metadata elastic/beats#16003
  • [x] add_kubernetes_metadata elastic/beats#16003
  • [x] add_locale#16654
  • [x] add_observer_metadata elastic/beats#16654
  • [ ] script/javascript/module/console
  • [ ] libbeat/publisher/ https://github.com/elastic/beats/pull/16886
  • [x] pipeline
  • [x] pipeline/stress
  • [x] processing
  • [ ] queue/queuetest
  • [x] libbeat/reader https://github.com/elastic/beats/pull/16886
  • [x] multiline
  • [x] readfile
  • [x] readjson
  • [x] libbeat/service elastic/beats#17028
  • [ ] libbeat/template elastic/beats#18258
  • [ ] libbeat/tests/compose

[botelastic[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[jlind23]

Closing for now as all tasks listed were achieved.