CloudNativePG assumes the underlying Kubernetes cluster has the required connectivity already set up. Networking on Kubernetes is an important and extended topic; please refer to the Kubernetes documentation for further information.

If you're following the quickstart guide to install CloudNativePG on a local KinD or K3d cluster, you should not encounter any networking issues as neither platform will add any networking restrictions by default.

However, when deploying CloudNativePG on existing infrastructure, networking restrictions might be in place that could impair the communication of the operator with PostgreSQL clusters. Specifically, existing Network Policies might restrict certain types of traffic.

Or, you might be interested in adding network policies in your environment for increased security. As mentioned in the security document, please ensure the operator can reach every cluster pod on ports 8000 and 5432, and that pods can connect to each other.

Cross-namespace network policy for the operator

Following the quickstart guide or using helm chart for deployment will install the operator in a dedicated namespace (cnpg-system by default). We recommend that you create clusters in a different namespace.

The operator must be able to connect to cluster pods. This might be precluded if there is a NetworkPolicy restricting cross-namespace traffic.

For example, the kubernetes guide on network policies contains an example policy denying all ingress traffic by default.

If your local kubernetes setup has this kind of restrictive network policy, you will need to create a NetworkPolicy to explicitly allow connection from the operator namespace and pod to the cluster namespace and pods. You can find an example in the networkpolicy-example.yaml file in this repository. Please note, you'll need to adjust the cluster name and cluster namespace to match your specific setup, and also the operator namespace if it is not the default namespace.

Cross-cluster networking

While bootstrapping from another cluster or when using the externalClusters section, ensure connectivity among all clusters, object stores, and namespaces involved.

Again, we refer you to the Kubernetes documentation for setup information.