feat: Update Elasticsearch json parser to use LoggingReceiverMacro

[dyl10s]

Description

Refactored the Elasticsearch json parser to use the LoggingReceiverMacro

I did need to add some yaml tags to fix a parsing panic

Related issue

How has this been tested?

Checklist:

• Unit tests
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• Integration tests
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• Documentation
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• Minor version bump
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[franciscovalentecastro]

Note: This is a general comment that i mentioned also in #1978 (comment). Another way of verifying that the refactor is correct is that the output_fluentbit.yaml should be the same before and after the update to elasticsearch.go.

[franciscovalentecastro]

LGTM!

[franciscovalentecastro]

Sorry for bringing this comments so late in the review process. Added some last suggested changes.

[franciscovalentecastro]

This change should prevent the YAML un-marshalling to validate recursively all fields in ReceiverMixin, thus not causing the panic with missing yaml tags.

Suggested change :

Suggested change

	ReceiverMixin confgenerator.LoggingReceiverFilesMixin `yaml:",inline"`
	ReceiverMixin confgenerator.LoggingReceiverFilesMixin `yaml:",inline" validate:"structonly"`

[franciscovalentecastro]

Sorry for bringing this comments so late in the review process. Now i'm realizing that since MultilineRule ¹ is a non-configurable feature (not exposed to users), these fields don't need and shouldn't have named yaml tags.

Note : I remember the updates in elasticsearch.go were causing some issues with a panic (missing tags) when running tests. I haven't been able to reproduce again, but i believe the other suggested change in elasticsearch.go should fix that.

Suggesting the following change :

Suggested change

	StateName string `yaml:"state_name,omitempty"`
	Regex string `yaml:"regex,omitempty"`
	NextState string `yaml:"next_state,omitempty"`
	StateName string
	Regex string
	NextState string

Footnotes

1. https://github.com/GoogleCloudPlatform/ops-agent/blob/master/confgenerator/logging_receivers.go#L74 ↩

[dyl10s]

Sorry for bringing this comments so late in the review process. Added some last suggested changes.

All good, got that fixed!

[franciscovalentecastro]

Previous commit passed most tests (see a483257). Merging.