Whats the best approach for multiple mongodb ReplicaSets on a cluster?

[TheDukeDK]

I had intended to install mgob on my k8s cluster and then add backup-config files to a central configMap whenever I added a mongodb replicaSet. We will have several mongodb replicaSets managed by the MongoDB Community Operator running a K8s cluster.

But it seems to require that we have at least one Backup Plan. This makes me wonder what the proper approach is...

One mgob per mongodb replicaSet?

Or can we have one mgob to handle all of our mongodb replicaSets on a cluster?

• One mongob to be installed in it's own namespace.
• Whenever we add a mongodb resource we would update the central configMap with a new entry.

kind: ConfigMap
apiVersion: v1
metadata:
  labels:
    role: mongo-backup
  name: mgob-config
  namespace: db
data:
  ##### Add and entry to this configmap for each mongodb we have #####
  mongodb-a.yml: |
    target:
      host: "mongodb-a-svc.namespace.svc.cluster.local,mongodb-a-0.mongodb-gb-svc.namespace.svc.cluster.local,mongodb-a-1.mongodb-gb-svc.namespace.svc.cluster.local,mongodb-a-2.mongodb-gb-svc.namespace.svc.cluster.local"
      port: 27017
      database: "admin"
    scheduler:
      cron: "*/1 * * * *"
      retention: 5
      timeout: 60
    retry:
      attempts: 3
      backoffFactor: 60
    s3:
      url: "https://api.minio.example.com"
      bucket: mongodb-a
      accessKey: "some-access-key"
      secretKey: "some-secret-key"
      api: "S3v4"
  mongodb-b.yml: |
    target:
      host: "mongodb-b-svc.namespace.svc.cluster.local,mongodb-b-0.mongodb-gb-svc.namespace.svc.cluster.local,mongodb-b-1.mongodb-gb-svc.namespace.svc.cluster.local,mongodb-b-2.mongodb-gb-svc.namespace.svc.cluster.local"
      port: 27017
      database: "admin"
    scheduler:
      cron: "*/1 * * * *"
      retention: 5
      timeout: 60
    retry:
      attempts: 3
      backoffFactor: 60
    s3:
      url: "https://api.minio.example.com"
      bucket: mongodb-b
      accessKey: "some-access-key"
      secretKey: "some-secret-key"
      api: "S3v4"

[TheDukeDK]

FYI: I have decided to go with one mgob statefulset per mmogodb replicaSet. Living in the same namespace as the replicaSet and deployed with custom resources instead of the helm chart.