Grafana-agent-operator: ability to run Integration as a StatefulSet

[james-callahan]

Request

When trying to run eventhandler as a logs integration, we need a volume to store the event cache.
I'm creating this with a PVC and attaching it to the Integration:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: grafana-agent-eventhandler
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
---
apiVersion: monitoring.grafana.com/v1alpha1
kind: Integration
metadata:
  name: eventhandler
  labels:
    grafana-agent: logs
spec:
  config:
    cache_path: /etc/eventhandler/eventhandler.cache
    logs_instance: default/grafana-agent-logs
  name: eventhandler
  type:
    unique: true
  volumeMounts:
    - mountPath: /etc/eventhandler
      name: eventhandler-cache
  volumes:
    - name: eventhandler-cache
      persistentVolumeClaim:
        claimName: grafana-agent-eventhandler

However, the integration runs as a Deployment, and when a new pod comes up (e.g. due to other changes such as a new grafana agent version), then the new pod comes up but is unable to mount the volume as it is already in use.

My first preference would be to be have the integration as a StatefulSet instead.

Second prize would be to at least be able to set the Deployment's strategy.type to Recreate instead of the default of RollingUpdate.

Use case

Stateful integrations.

[github-actions]

This issue has not had any activity in the past 30 days, so the needs-attention label has been added to it.
If the opened issue is a bug, check to see if a newer release fixed your issue. If it is no longer relevant, please feel free to close this issue.
The needs-attention label signals to maintainers that something has fallen through the cracks. No action is needed by you; your issue will be kept open and you do not have to respond to this comment. The label will be removed the next time this job runs if there is new activity.
Thank you for your contributions!

[morsik]

Just went to identical issue.

It's even in official documentation that eventhandler should be run as StatefulSet: https://grafana.com/docs/agent/latest/static/configuration/integrations/integrations-next/eventhandler-config/ but this limitation makes it impossible.

To use the cache feature and maintain state in a Kubernetes environment, a StatefulSet must be used.