feat: Add tests and add feature to update daemonset to have selector

[rivToadd]

Description:

add feature to update daemonset to have selector field

Link to tracking Issue(s):

• Resolves: VPA does not work when using DaemonSet mode #2605

Testing:
wrote unit tests for said feature

ran test on local kind cluster:

yaml spec used to deploy:

apiVersion: opentelemetry.io/v1alpha1
kind: OpenTelemetryCollector
metadata:
  name: logs
  labels:
    app: logs
spec:
  mode: daemonset
  hostNetwork: true
  config: |
    receivers:
      jaeger:
        protocols:
          grpc:
    processors:

    exporters:
      debug:
        verbosity: detailed

    service:
      pipelines:
        traces:
          receivers: [jaeger]
          processors: []
          exporters: [debug]
  priorityClassName: system-cluster-critical
  resources:
    limits:
      memory: 128Mi
    requests:
      cpu: 10m
      memory: 128Mi
  tolerations:
  - operator: Exists
  volumeMounts:
  - mountPath: /var/log
    name: varlog
    readOnly: true
  volumes:
  - hostPath:
      path: /var/log
    name: varlog

---

apiVersion: autoscaling.k8s.io/v1
kind: VerticalPodAutoscaler
metadata:
  name: logs-collector
spec:
  resourcePolicy:
    containerPolicies:
    - containerName: '*'
      controlledResources:
      - cpu
      - memory
  targetRef:
    apiVersion: opentelemetry.io/v1alpha1
    kind: OpenTelemetryCollector
    name: logs
  updatePolicy:
    updateMode: Auto

Logs that I saw on VPA

I0226 22:37:30.086614       1 matcher.go:68] Let's choose from 1 configs for pod default/logs-collector-%
I0226 22:37:30.086717       1 recommendation_provider.go:91] updating requirements for pod logs-collector-%.
I0226 22:37:30.086839       1 server.go:112] Sending patches: [{add /spec/containers/0/resources/requests/memory 262144k} {add /spec/containers/0/resources/requests/cpu 25m} {add /spec/containers/0/resources/limits/memory 262144k} {add /metadata/annotations/vpaUpdates Pod resources updated by logs-collector: container 0: memory request, cpu request, memory limit} {add /metadata/annotations/vpaObservedContainers otc-container}]

resulting in new resource limits on collector pod

   Limits:
      memory:  262144k
    Requests:
      cpu:     25m
      memory:  262144k

Documentation:

[swiatekm]

LGTM overall. Have you tested if the VPA works correctly after this change?

[rivToadd]

@swiatekm-sumo I've updated the PR description to document the local testing that I did.