[Azure Blob Storage] Adding integration for Custom Azure Blob Storage Input

[P1llus]

What does this PR do?

This adds support for using the custom Azure Blob Storage Input that was added to filebeat in 8.5.0.

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.

Related issues

• Closes Custom Azure Blob input package #4331

[elasticmachine]

Pinging @elastic/security-external-integrations (Team:Security-External Integrations)

[P1llus]

Similar to #4692

There is currently a few questions up for discussion here:

1. Will we add system tests, and how we should do it.
2. Which ECS fields should we use, continuing a discussion around if we should include at least fields related to common metadata processors.
3. Needs a new icon.

[elasticmachine]

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• Start Time: 2023-02-07T08:53:37.581+0000

• Duration: 14 min 4 sec

Test stats 🧪

Test	Results
Failed	0
Passed	3
Skipped	0
Total	3

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[P1llus]

Integration has not been fully tested yet, but will be soon (before merging)

[elasticmachine]

🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	100.0% (0/0)	💚
Files	100.0% (0/0)	💚
Classes	100.0% (0/0)	💚
Methods	100.0% (3/3)	💚
Lines	100.0% (0/0)	💚
Conditionals	100.0% (0/0)	💚

[kcreddy]

LGTM 👍🏼
Once we have a way to run system tests, we could change to GA.

[botelastic]

Hi! We just realized that we haven't looked into this PR in a while. We're sorry! We're labeling this issue as Stale to make it hit our filters and make sure we get back to it as soon as possible. In the meantime, it'd be extremely helpful if you could take a look at it as well and confirm its relevance. A simple comment with a nice emoji will be enough :+1. Thank you for your contribution!

[narph]

@P1llus , can we get this in?

[P1llus]

Was waiting for elastic/stream#47 to finalize and be merged, and wanted to wait for the dynamic ECS template functionality that was very recently merged here: elastic/elastic-package#1073 so that we could include this functionality from the initial version of the package.

[P1llus]

All blocking features have now been resolved, will just have to update the PR with the system test and add dynamic ECS template before merging: #5055

[P1llus]

This new input needs to be added to the filebeat spec file for elastic-agent first: https://github.com/elastic/elastic-agent/blob/main/specs/filebeat.spec.yml

[P1llus]

Spec file updated as per: elastic/elastic-agent#2149
Awaiting new snapshot image to be generated.

[ShourieG]

minor doc changes otherwise LGTM

[elasticmachine]

Package azure_blob_storage - 0.1.0 containing this change is available at https://epr.elastic.co/search?package=azure_blob_storage