(feat) Make exporter sidecar more generic

[utdrmac]

The operator currently has a metrics exporter sidecar, however, the implementation is tailored to a specific container image, and does not allow for any custom parameters, environment variables, etc. This feature request aims to "generic-ify" the exporter sidecar so that any container image can be used by the end-user.

Spec Changes Proposal

spec:
  metrics:
    enabled: true
    image: "oliver006/redis_exporter:v1.80.0"
    imagePullSecret: gitlab-cr-token
    command: ["some-exporter", "--flag1", "--flag2=foobar"]
    port: 9121
    resources:
      limits:
        cpu: 100m
        memory: 128Mi
    extraSecretsMounts:
      "some-secret": "/path/to/mount"
    extraEnvMounts:
      "some-configmap": "/path/config"

• If spec.image is not specified, then command, and port are ignored, and will use existing values.

  • Any other provided options will be merged into the existing container.

• If spec.image is not the same as default image, then command and port are required.

• If only spec.metrics.enabled=true is specified, the behavior is the same for backwards compatibility.

• I'm willing to implement this feature