Replace ecs version with attribute

[karenzone]

Related to #1169
This PR replaces the hard-coded ECS version number with an attribute that supports versioning.

DO NOT MERGE until all books using the hard-coded ECS attribute have been updated to include //shared/versions/stack/{source_branch}.asciidoc (or handled in product repo versioning)

• Logstash Reference
• Beats (libbeat and winlogbeat)
• Kibana Reference ([DOCS] Updates location of version attribute for Kibana Guide kibana#45051)
  • SIEM
  • ML
  • Logs. Note to self: This reference is weird. Check it out to verify or correct before merge.
• SIEM Guide (stack-docs) (Updates location of version attribute for multiple books stack-docs#497)

[karenzone]

@webmat FYI: More steps toward implementing ECS versioning

[karenzone]

@dedemorton Here are the ECS versioning changes. Both LS and Beats handle versioning in the repo. Toward your vision outlined in #804, I'm considering switching Logstash to use this versioning approach. I'd appreciate your eyes on this PR (elastic/logstash#11125) to make sure I'm not overlooking any constraints.

[karenzone]

run elasticsearch-ci/docs rebuild

[karenzone]

@bmorelli25 If I'm interpreting the CI errors correctly, we might need to add a link to shared versions (include::{asciidoc-dir}/../../shared/versions/stack/{source_branch}.asciidoc[]) in https://raw.githubusercontent.com/elastic/apm-agent-python/master/docs/index.asciidoc

If that's the right fix, I'm happy to make the fix and tag you as a reviewer. Let's discuss.

[bmorelli25]

Ahhh good find. Yup, looks like we probably need to include that file in all of the APM Agents to be safe.

[bmorelli25]

Will that work though? There are no asciidoc files in https://github.com/elastic/docs/tree/master/shared/versions/stack that match the current python version of 5.x. Same for the other APM Agent versions. They're all <5.

This why we currently hardcode :branch: current in https://raw.githubusercontent.com/elastic/apm-agent-python/master/docs/index.asciidoc.

[bmorelli25]

@karenzone Now that you've pointed this out, I'm seeing the same problem in #1187 with Agent to Agent links also failing because they don't include the shared version file.

I noticed you have the ECS docs including 7.x version file. I'm not sure that makes sense for APM. I see there was a lot of discussion around it in elastic/ecs#550.

I almost wonder if it makes sense to add another file to https://github.com/elastic/docs/tree/master/shared/versions/stack called other_versions (or something like that). This file could then "include" the correct current version file that folder? I'm not sure if that makes sense, but I'm trying to figure out how we can have all versions be set from the docs repo.

[karenzone]

run elasticsearch-ci/docs rebuild

[bmorelli25]

@karenzone I just merged the backport. You may want to restart this build. I think it will fail as it was started before that PR was merged.

[karenzone]

run elasticsearch-ci/docs rebuild

[lcawl]

LGTM, congrats!