Skip to content

Metadata

[!NOTE]
This documentation applies to mariadb-operator version >= v0.0.28

This documentation shows how to configure metadata in the mariadb-operator CRs.

Table of contents

Children object metadata

MariaDB and MaxScale resources allow you to propagate metadata to all the children objects by specifying the inheritMetadata field:

apiVersion: k8s.mariadb.com/v1alpha1
kind: MariaDB
metadata:
  name: mariadb-galera
spec:
  inheritMetadata:
    labels:
      database.myorg.io: mariadb
    annotations:
      database.myorg.io: mariadb

This means that all the reconciled objects will inherit these labels and annotations. For instance, see the Services and Pods:

apiVersion: v1
kind: Service
metadata:
  annotations:
    database.myorg.io: mariadb
  labels:
    database.myorg.io: mariadb
  name: mariadb-galera-primary
  namespace: default

apiVersion: v1
kind: Pod
metadata:
  annotations:
    database.myorg.io: mariadb
  labels:
    database.myorg.io: mariadb
  name: mariadb-galera-0
  namespace: default

Pod metadata

You have the ability to provide dedicated metadata for Pods by specifying the podMetadata field in any CR that reconciles a Pod, for instance: MariaDB, MaxScale, Backup, Restore and SqlJobs:

apiVersion: k8s.mariadb.com/v1alpha1
kind: Backup
metadata:
  name: backup
spec:
  inheritMetadata:
    labels:
      sidecar.istio.io/inject: "true"
    annotations:
      database.myorg.io: mariadb
  podMetadata:
    labels:
      sidecar.istio.io/inject: "false"

It is important to note that the podMetadata field superseeds the inheritMetadata field, therefore the labels and annotations provided in the former will override the ones in the latter.

Service metadata

Provision dedicated metadata for Services in the MariaDB resources can be done via the service, primaryService and secondaryService fields:

apiVersion: k8s.mariadb.com/v1alpha1
kind: MariaDB
metadata:
  name: mariadb-galera
spec:
  service:
    type: LoadBalancer
    metadata:
      annotations:
        metallb.universe.tf/loadBalancerIPs: 172.18.0.150

  primaryService:
    type: LoadBalancer
    metadata:
      annotations:
        metallb.universe.tf/loadBalancerIPs: 172.18.0.160

  secondaryService:
    type: LoadBalancer
    metadata:
      annotations:
        metallb.universe.tf/loadBalancerIPs: 172.18.0.161

In the case of MaxScale, you can also do this via the kubernetesService field.

Refer to the HA documentation to know more about the Service fields and MaxScale.

PVC metadata

Both MariaDB and MaxScale allow you to define a volumeClaimTemplate to be used by the underlying StatefulSet. You may also define metadata for it:

apiVersion: k8s.mariadb.com/v1alpha1
kind: MariaDB
metadata:
  name: mariadb-galera
spec:
  storage:
    size: 1Gi
    volumeClaimTemplate:
      metadata:
        annotations:
          database.myorg.io: mariadb
        labels:
          database.myorg.io: mariadb
      accessModes:
      - ReadWriteOnce
      resources:
        requests:
          storage: 1Gi

Use cases

Being able to provide metadata allows you to integrate with other CNCF landscape projects:

Metallb

If you run on bare metal and you use Metallb for managing the LoadBalancer objects, you can declare its IPs via annotations:

apiVersion: k8s.mariadb.com/v1alpha1
kind: MariaDB
metadata:
  name: mariadb-galera
spec:
  service:
    type: LoadBalancer
    metadata:
      annotations:
        metallb.universe.tf/loadBalancerIPs: 172.18.0.150

Istio

Istio injects the data plane container to all Pods, but you might want to opt-out of this feature in some cases:

apiVersion: k8s.mariadb.com/v1alpha1
kind: Backup
metadata:
  name: backup
spec:
  podMetadata:
    labels:
      sidecar.istio.io/inject: "false"

For instance, you probably don't want to inject the Istio sidecar to Backup Pods, as it will prevent the Jobs from finishing and therefore your backup process will hang.

Reference