Make logstash/node_stats metricset work for Stack Monitoring without xpack.enabled flag

[sayden]

Ready to test

[elasticmachine]

Pinging @elastic/stack-monitoring (Stack monitoring)

[elasticmachine]

Pinging @elastic/integrations-services (Team:Services)

[elasticmachine]

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• Build Cause: Pull request #21546 updated

• Start Time: 2020-12-15T16:35:40.600+0000

• Duration: 66 min 38 sec

Test stats 🧪

Test	Results
Failed	0
Passed	2277
Skipped	524
Total	2801

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Test	Results
Failed	0
Passed	2277
Skipped	524
Total	2801

[chrisronline]

I'm seeing this error when running this:

2020-10-23T14:14:48.531-0400 ERROR [publisher_pipeline_output] pipeline/output.go:154 Failed to connect to backoff(elasticsearch(https://localhost:9200)): Connection marked as failed because the onConnect callback failed: error loading template: could not load template. Elasticsearch returned: couldn't load template: 400 Bad Request: {"error":{"root_cause":[{"type":"mapper_parsing_exception","reason":"Invalid [path] value [logstash.node.stats.events.duration_in_millis] for field alias [logstash.stats.events.duration.ms]: an alias must refer to an existing field in the mappings."}],"type":"mapper_parsing_exception","reason":"Invalid [path] value [logstash.node.stats.events.duration_in_millis] for field alias [logstash.stats.events.duration.ms]: an alias must refer to an existing field in the mappings."},"status":400}. Response body: {"error":{"root_cause":[{"type":"mapper_parsing_exception","reason":"Invalid [path] value [logstash.node.stats.events.duration_in_millis] for field alias [logstash.stats.events.duration.ms]: an alias must refer to an existing field in the mappings."}],"type":"mapper_parsing_exception","reason":"Invalid [path] value [logstash.node.stats.events.duration_in_millis] for field alias [logstash.stats.events.duration.ms]: an alias must refer to an existing field in the mappings."},"status":400}.

[chrisronline]

LGTM! UI loads up as expected!

[ycombinator]

I think we will need to call m.CheckPipelineGraphAPIsAvailable() every time now, right, since we plan to always call the Logstash Pipeline Graph APIs in the Fetch() method, no?

[sayden]

I removed it because I didn't see any call to this method anywhere, haha. Anyways I guess it should be included so I added it back into the Fetch call directly.

[ycombinator]

This is looking mostly good. Just left one comment/question.

[ycombinator]

I left a comment/question a few minutes ago. Besides that, everything in this PR LGTM. So I'm approving it for merge now. Feel free to address my comment before merging or after, in the feature branch, as you prefer.