Percona Operator for PostgreSQL single-namespace and multi-namespace deployment¶

There are two design patterns that you can choose from when deploying Percona Operator for PostgreSQL and PostgreSQL clusters in Kubernetes:

Namespace-scope - one Operator per Kubernetes namespace,
Cluster-wide - one Operator can manage clusters in multiple namespaces.

This how-to explains how to configure Percona Operator for PostgreSQL for each scenario.

Namespace-scope¶

By default, Percona Operator for PostgreSQL functions in a specific Kubernetes namespace. You can create default pgo one or some other Namespace during installation (like it is shown in the installation instructions). This approach allows several Operators to co-exist in one Kubernetes-based environment, being separated in different namespaces:

Normally this is a recommended approach, as isolation minimizes impact in case of various failure scenarios. This is the default configuration of our Operator.

Let’s say you have a Namespace in your Kubernetes cluster called percona-db-1.

Edit the following lines in your deploy/operator.yaml:

apiVersion: v1
kind: ConfigMap
metadata:
name: pgo-deployer-cm
data:
  values.yaml: |-
  ...
    namespace: "percona-db-1"
    pgo_operator_namespace: "percona-db-1"

...
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: pgo-deployer-crb
subjects:
...

  - kind: ServiceAccount
    namespace: percona-db-1

Deploy the Operator:

$ kubectl apply -f deploy/operator.yaml -n percona-db-1

Once Operator is up and running, deploy the database cluster itself:
```
$ kubectl apply -f deploy/cr.yaml -n percona-db-1
```

You can deploy multiple clusters in this namespace.

Add more namespaces¶

What if there is a need to deploy clusters in another namespace? The solution for namespace-scope deployment is to have more than one Operator in the corresponding namespace. We will use the percona-db-2 namespace as an example.

Edit or copy operator.yaml:

apiVersion: v1
kind: ConfigMap
metadata:
  name: pgo-deployer-cm
data:
  values.yaml: |-
...
     namespace: "percona-db-2"
     pgo_operator_namespace: "percona-db-2"

...
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: pgo-deployer-crb
subjects:
...
   - kind: ServiceAccount
    namespace: percona-db-2

Deploy the Operator:

$ kubectl apply -f deploy/operator.yaml -n percona-db-2

Once Operator is up and running deploy the database cluster itself:
```
$ kubectl apply -f deploy/cr.yaml -n percona-db-2
```
Note

Cluster names may be the same in different namespaces.

Install the Operator cluster-wide¶

Sometimes it is more convenient to have one Operator watching for Percona Distribution for PostgreSQL custom resources in several namespaces.

We recommend running Percona Operator for PostgreSQL in a traditional way, limited to a specific namespace. But it is possible to run it in so-called cluster-wide mode, one Operator watching several namespaces, if needed:

Note

Please take into account that if several Operators are configured to watch the same namespace, it is entirely unpredictable which one will get ownership of the Custom Resource in it, so this situation should be avoided.

The following simple example shows how to install Operator cluster-wide on Kubernetes. It does the following:

deploys Operator into a separate percona-operator Namespace,
allows Operator to control databases in two Namespaces: percona-db-1 and percona-db-2.

Edit the following lines in your deploy/operator.yaml:

apiVersion: v1
kind: ConfigMap
metadata:
  name: pgo-deployer-cm
data:
  values.yaml: |-
  ...
    namespace: "percona-db-1,percona-db-2"
    pgo_operator_namespace: "percona-operator"

...
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: pgo-deployer-crb
subjects:
...
  - kind: ServiceAccount
    namespace: percona-operator

Note

Before deploying the Operator, please ensure that all Namespaces exist.

Deploy the Operator:

$ kubectl apply -f deploy/operator.yaml -n percona-operator

You can now deploy databases into the namespaces listed in the namespace: variable.

$ kubectl apply -f deploy/cr.yaml -n percona-db-1
$ kubectl apply -f deploy/cr.yaml -n percona-db-2

Add more namespaces¶

Let’s say we want the Operator to manage databases in one more Namespace: percona-db-3.

Edit the operator.yaml and add one more Namespace into the corresponding field:

apiVersion: v1
kind: ConfigMap
metadata:
  name: pgo-deployer-cm
data:
  values.yaml: |-
  ...
    namespace: "percona-db-1,percona-db-2,percona-db-3"

Delete the Operator deployment and deploy job:
```
$ kubectl -n percona-operator delete -f deploy/operator.yaml
$ kubectl -n percona-operator delete deploy postgres-operator
```
Note

Deletion of the Operator does not affect your existing clusters’ availability, but limits your ability to manage them. For example, you will not be able to scale the clusters or take backups.

Deploy the Operator again with the new Namespace added:

$ kubectl apply -f deploy/operator.yaml -n percona-operator

You can now deploy databases into the new Namespace:
```
$ kubectl apply -f deploy/cr.yaml -n percona-db-3
```

Last update: 2022-09-21