How to mount alertmanager storage to PVC?

[hillbun]

alertmanager-main-0
alertmanager-main-1
alertmanager-main-2

I need mount all alertmanager pods storage to PVC, how to do?

they share same data or not?

[metalmatze]

Each replica will have it's own PVC, then state is shared between those replicas with gossiping.
You'll need to add storage to the AlertmanagerSpec.

Something like:

apiVersion: monitoring.coreos.com/v1
kind: Alertmanager
metadata:
  labels:
    alertmanager: main
    app.kubernetes.io/component: alert-router
    app.kubernetes.io/name: alertmanager
    app.kubernetes.io/part-of: kube-prometheus
    app.kubernetes.io/version: 0.21.0
  name: main
  namespace: monitoring
spec:
  image: quay.io/prometheus/alertmanager:v0.21.0
  nodeSelector:
    kubernetes.io/os: linux
  podMetadata:
    labels:
      app.kubernetes.io/component: alert-router
      app.kubernetes.io/name: alertmanager
      app.kubernetes.io/part-of: kube-prometheus
      app.kubernetes.io/version: 0.21.0
  replicas: 3
  resources:
    limits:
      cpu: 100m
      memory: 100Mi
    requests:
      cpu: 4m
      memory: 100Mi
  securityContext:
    fsGroup: 2000
    runAsNonRoot: true
    runAsUser: 1000
  serviceAccountName: alertmanager-main
  version: 0.21.0
+  storage:
+    volumeClaimTemplate:
+      metadata:
+        name: alertmanager
+      spec:
+        accessModes:
+          - ReadWriteOnce
+        volumeMode: Filesystem
+        resources:
+          requests:
+            storage: 8Gi
+        storageClassName: slow