[helm]: implement support for defining image pull secrets

[pkoutsovasilis]

What does this PR do?

This PR that adds support for defining pullImageSecrets support in the chart

Why is it important?

Users mights need to deploy an agent image from a private repository

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in ./changelog/fragments using the changelog tool
• I have added an integration test or an E2E test

Disruptive User Impact

N/A

How to test this PR locally

mage integration:kubernetesMatrix

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[blakerouse]

Looks good.

[swiatekm]

I think it's more idiomatic to attach these to a ServiceAccount instead of the Pod, but in this case it doesn't matter too much.

Also, can you actually set this in one of the examples?

[pkoutsovasilis]

I think it's more idiomatic to attach these to a ServiceAccount instead of the Pod, but in this case it doesn't matter too much.

I don't have a preference of one way (ServiceAccount attachment) over the other (Pod attachment), but since there is this draft PR (planning on working on that soon) that will allow the users to complete override service accounts I chose the latter to deterministically always apply the imagePullSecrets and not allow it to be overidden.

Also, can you actually set this in one of the examples?

I can mention it but having it actually in the example cli commands I don't think so as I don't have a guaranteed elastic-agent image under a private registry and I would like to keep the examples as simple as a straight-forward copy-paste. Would that work or you had something else in mind?

[swiatekm]

I can mention it but having it actually in the example cli commands I don't think so as I don't have a guaranteed elastic-agent image under a private registry and I would like to keep the examples as simple as a straight-forward copy-paste. Would that work or you had something else in mind?

That's fine. I mostly just want a sanity check that the template works as expected, but for a change as simple as this one it's not that important.

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
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