Implement template rendering action

[lburgazzoli]

Description

This PR introduces a new rendering engine that is based on the go text/template package.

The template is rendered to the actual objects taking a subset of the ReconciliationRequest struct: Instance and DSCI so as an example, the ServiceMeshMember template that is part of the model registry component would looks like:

apiVersion: maistra.io/v1
kind: ServiceMeshMember
metadata:
  name: default
  namespace: {{.Instance.Spec.RegistriesNamespace}}
spec:
  controlPlaneRef:
    namespace: {{ .DSCI.Spec.ServiceMesh.ControlPlane.Namespace }}
    name: {{ .DSCI.Spec.ServiceMesh.ControlPlane.Name }}

https://issues.redhat.com/browse/RHOAIENG-15534

How Has This Been Tested?

1. Enable the model registry component in DSC
2. Check for the presence of a ServiceMeshMember instance in the model registries namespace named default and that it contains the expected values
3. Check metrics related to the render action, it should include something like:

# HELP action_renderer_manifests_total Number of rendered resources
# TYPE action_renderer_manifests_total counter
action_renderer_manifests_total{controller="modelregistry",engine="kustomize"} 17
action_renderer_manifests_total{controller="modelregistry",engine="template"} 1

Screenshot or short clip

Merge criteria

• You have read the contributors guide.
• Commit messages are meaningful - have a clear and concise summary and detailed explanation of what was changed and why.
• Pull Request contains a description of the solution, a link to the JIRA issue, and to any dependent or related Pull Request.
• Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has manually tested the changes and verified that the changes work

[codecov]

Codecov Report

Attention: Patch coverage is 73.56322% with 23 lines in your changes missing coverage. Please review.

Please upload report for BASE (feature-operator-refactor@1209501). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
...actions/render/template/action_render_templates.go	73.25%	17 Missing and 6 partials ⚠️

Additional details and impacted files

@@                     Coverage Diff                      @@
##             feature-operator-refactor    #1364   +/-   ##
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  Coverage                             ?   26.68%           
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  Files                                ?       55           
  Lines                                ?     4455           
  Branches                             ?        0           
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  Hits                                 ?     1189           
  Misses                               ?     3125           
  Partials                             ?      141           

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[grdryn]

/lgtm

[zdtsw]

the pat only accept file name not the folder name, not for this PR, but we will need extend it a bit later if we have multiple templates

[lburgazzoli]

if you have multiple templates, the you can pass multiple paths, I didn't want to make it over complicated at this stage given we have only a few templates.

But yeah, it would probably be useful. I'll have a look for a follow up PR

[zdtsw]

LGTM

[lburgazzoli]

/retest

[lburgazzoli]

@zdtsw renamed Instance -> Component as it sounds better

[lburgazzoli]

@zdtsw renamed Instance -> Component as it sounds better

[lburgazzoli]

/retest

[lburgazzoli]

/retest

[grdryn]

/lgtm

[openshift-ci]

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This pull-request has been approved by: grdryn, zdtsw

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