Add merge-json-log to event router

[mburke5678]

https://bugzilla.redhat.com/show_bug.cgi?id=1758222

[openshift-docs-preview-bot]

The preview will be available shortly at:

• https://logging-event-router-merge-jspn--ocpdocs.netlify.com/

[mburke5678]

Hold PR pending possible code change per @richm

[anpingli]

LGTM

[richm]

nack - so the PR openshift/origin-aggregated-logging#1766 will basically enable merge_json_log implicitly for eventrouter events (assuming the documentation has been followed to deploy the eventrouter) - with that PR, the user does not have to enable MERGE_JSON_LOG=true to use eventrouter

[richm]

Fluentd will automatically parse JSON logs that come from Pods whose names match eventrouter-*, which is the naming convention used in the example configuration.

[richm]

That is, I don't think we should mention MERGE_JSON_LOG here.

[richm]

Instead of this, say something like

You must set `TRANSFORM_EVENTS=true` in order to process and store eventrouter events in Elasticsearch.  In order to do this, you must set cluster logging to the unmanaged state.

Then add a link to the docs where we explain how to set cluster logging to the unmanaged state. Then

oc set env ds/fluentd TRANSFORM_EVENTS=true

[richm]

should I close this PR?

It depends - if we have already documented that you have to set TRANSFORM_EVENTS=true and set cluster logging to unmanaged in order to use eventrouter, then yes, you can close this PR.

[mburke5678]

@richm

should I close this PR?

Sorry, I didn't see your comment on TRANSFORM_EVENTS until after I posted that comment.
I added TRANSFORM_EVENTS in the latest commit

[richm]

/lgtm

[mburke5678]

@anpingli Can I ask you to take another look based on Rich's comments?