Setup an independent build for x-pack/winlogbeat

[andrewkroh]

Put the infrastructure in place to give x-pack/winlogbeat its own independent build.
This adds some utility code that can be used by other beats to reduce duplication.

cd winlogbeat && mage -l
Targets:
  goTestUnit            is an alias for goUnitTest.
  update                is an alias for update:all.
  check                 formats code, updates generated content, check for common errors, and checks for any modified files.
  clean                 cleans all generated files and build artifacts.
  dumpVariables         writes the template variables and values to stdout.
  fmt                   formats source code (.go and .py) and adds license headers.
  build                 builds the Beat binary.
  buildGoDaemon         builds the go-daemon binary (use crossBuildGoDaemon).
  crossBuild            cross-builds the beat for all target platforms.
  crossBuildGoDaemon    cross-builds the go-daemon binary using Docker.
  golangCrossBuild      build the Beat binary inside of the golang-builder.
  packageTest           tests the generated packages in build/distributions.
  dashboards:export     exports a dashboard from Kibana and writes it into the correct directory.
  dashboards:import     imports dashboards to Kibana using the Beat setup command.
  docs                  generates the documentation for the Beat.
  test                  runs all available tests (unitTest + integTest).
  goUnitTest            executes the Go unit tests.
  pythonUnitTest        executes the python system tests.
  unitTest              executes the unit tests (Go and Python).
  update:all            updates all generated content.
  update:config         updates the Beat's config files.
  update:dashboards     collects all the dashboards and generates index patterns.
  update:fieldDocs      updates the field documentation.
  update:fields         updates all fields files (.go, .yml).
  package               packages the Beat for distribution.

[ruflin]

Skimmed through it and so far looks good to me. But I think me or someone else should go through it again in more detail.

If I understand this correctly quite a few of the changes are actual cleanups of the existing code and not directly related to the x-pack/winlogbeat? I wonder if we should split it up in more PR's? ;-)

[andrewkroh]

I wonder if we should split it up in more PR's? ;-)

This is the split up version of the massive #9842. 😅

[ruflin]

I'm pretty sure I asked there the same question 🤦‍♂️

[ruflin]

LGTM, great job.

Would be great to have a deep dive session for beats contributors on all the mage magic at one time in the future ;-)

[ruflin]

mage:import is great and will simplify things a lot.

[ruflin]

This feels quite a bit hidden in scripts package but not something to address for this PR, more a general comment.

[ruflin]

Nit: Had to search for the definition of this. Would probably be nicer to have a more descriptive name or defined directly in here.