New Script: Prometheus Alertmanager

[andygrunwald]

✍️ Description

This Pull Request provides a new Script: Prometheus Alertmanager.

This is the Alerting-Part of Prometheus, see https://prometheus.io/docs/alerting/latest/overview/

Prometheus is already part of this repository.

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• Related Discussion: [Script request] Alertmanager #1005

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🛠️ Type of Change

Please check the relevant options:

• Bug fix (non-breaking change that resolves an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change unexpectedly)
• New script (a fully functional and thoroughly tested script or set of scripts)

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✅ Prerequisites

The following steps must be completed for the pull request to be considered:

• Self-review performed (I have reviewed my code to ensure it follows established patterns and conventions.)
• Testing performed (I have thoroughly tested my changes and verified expected functionality.)
• Documentation updated (I have updated any relevant documentation)

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📋 Additional Information (optional)

This is a near copy of the Prometheus scripts.
The setup is 1:1 the same.

I would appreciate a proper testing from your side as well.
This is my first script contribution.

[MickLesk]

Why not integrating in existing Prometheus Script als optional Installation/addon?

[andygrunwald]

@MickLesk This would be an option. I didn't do this for two reasons:

1. The standalone implementation was very straightforward
2. The tooling around this ecosystem (Prometheus, Alertmanager, VictoriaMetrics with vmalert, vmagent or Thanos) is component-based by design with the usecase to "mix and match" like you want - This means there are usecases where you just want to have an Alertmanager without Prometheus (e.g., just to use the Alerting system, but not the metrics system)

Re 1): Is there an example script where I can get some orientation about how to do it?

Re 2): There might be an argument that those use cases would not use the Proxmox scripts, and this might be right. For a home lab to experiment, this may still be valid.

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Should this stay standalone or should this be integrated into the Prometheus script?
My personal preference would be the standalone version, also due to maintenance.

[andygrunwald]

As far as I can see, the license is there, but the "Validate scripts" Github action still fails.

[andygrunwald]

@michelroegl-brunner @MickLesk I rebased the branch against latest main and fixed all CI checks.

The CI check "Validate scripts / Check changed files (pull_request) " is failing, due to

data: {
      message: 'Resource not accessible by integration',
      documentation_url: 'https://docs.github.com/rest/issues/comments#create-an-issue-comment',
      status: '403'
    }

This seem to be unrelated to the change and rather related to the CI check itself.