Quickstart

This section describes how to test a PostgreSQL cluster on your laptop/computer using Cloud Native PostgreSQL on a local Kubernetes cluster in Minikube or Kind.

RedHat OpenShift Container Platform users can test the certified operator for Cloud Native PostgreSQL on the Red Hat CodeReady Containers (CRC) for OpenShift.

Warning

The instructions contained in this section are for demonstration, testing, and practice purposes only and must not be used in production.

Like any other Kubernetes application, Cloud Native PostgreSQL is deployed using regular manifests written in YAML.

By following the instructions on this page you should be able to start a PostgreSQL cluster on your local Kubernetes/Openshift installation and experiment with it.

Important

Make sure that you have kubectl installed on your machine in order to connect to the Kubernetes cluster, or oc if using CRC for OpenShift. Please follow the Kubernetes documentation on how to install kubectl or the Openshift one on how to install oc.

Note

If you are running Openshift, use oc every time kubectl is mentioned in this documentation. kubectl commands are compatible with oc ones.

Part 1 - Setup the local Kubernetes/Openshift playground

The first part is about installing Minikube, Kind, or CRC. Please spend some time reading about the systems and decide which one to proceed with. After setting up one of them, please proceed with part 2.

Minikube

Minikube is a tool that makes it easy to run Kubernetes locally. Minikube runs a single-node Kubernetes cluster inside a Virtual Machine (VM) on your laptop for users looking to try out Kubernetes or develop with it day-to-day. Normally, it is used in conjunction with VirtualBox.

You can find more information in the official Kubernetes documentation on how to install Minikube in your local personal environment. When you installed it, run the following command to create a minikube cluster:

minikube start

This will create the Kubernetes cluster, and you will be ready to use it. Verify that it works with the following command:

kubectl get nodes

You will see one node called minikube.

Kind

If you do not want to use a virtual machine hypervisor, then Kind is a tool for running local Kubernetes clusters using Docker container "nodes" (Kind stands for "Kubernetes IN Docker" indeed).

Install kind on your environment following the instructions in the Quickstart, then create a Kubernetes cluster with:

kind create cluster --name pg

CodeReady Containers (CRC)

Download RedHat CRC and move the binary inside a directory in your PATH.

You can then run the following commands:

crc setup
crc start

The crc start output will explain how to proceed. You'll then need to execute the output of the crc oc-env command. After that, you can log in as kubeadmin with the printed oc login command. You can also open the web console running crc console. User and password are the same as for the oc login command.

CRC doesn't come with a StorageClass, so one has to be configured. You can follow the Dynamic volume provisioning wiki page and install rancher/local-path-provisioner.

Part 2 - Install Cloud Native PostgreSQL

Now that you have a Kubernetes or OpenShift installation up and running on your laptop, you can proceed with Cloud Native PostgreSQL installation.

Please refer to the "Installation" section and then proceed with the deployment of a PostgreSQL cluster.

Part 3 - Deploy a PostgreSQL cluster

As with any other deployment in Kubernetes, to deploy a PostgreSQL cluster you need to apply a configuration file that defines your desired Cluster.

The cluster-example.yaml sample file defines a simple Cluster using the default storage class to allocate disk space:

# Example of PostgreSQL cluster
apiVersion: postgresql.k8s.enterprisedb.io/v1
kind: Cluster
metadata:
  name: cluster-example
spec:
  instances: 3

  # Example of rolling update strategy:
  # - unsupervised: automated update of the primary once all
  #                 replicas have been upgraded (default)
  # - supervised: requires manual supervision to perform
  #               the switchover of the primary
  primaryUpdateStrategy: unsupervised

  # Require 1Gi of space
  storage:
    size: 1Gi

There's more

For more detailed information about the available options, please refer to the "API Reference" section.

In order to create the 3-node PostgreSQL cluster, you need to run the following command:

kubectl apply -f cluster-example.yaml

You can check that the pods are being created with the get pods command:

kubectl get pods

By default, the operator will install the latest available minor version of the latest major version of PostgreSQL when the operator was released. You can override this by setting the imageName key in the spec section of the Cluster definition. For example, to install PostgreSQL 12.5:

apiVersion: postgresql.k8s.enterprisedb.io/v1
kind: Cluster
metadata:
   # [...]
spec:
   # [...]
   imageName: quay.io/enterprisedb/postgresql:12.5
   #[...]

Important

The immutable infrastructure paradigm requires that you always point to a specific version of the container image. Never use tags like latest or 13 in a production environment as it might lead to unpredictable scenarios in terms of update policies and version consistency in the cluster. For strict deterministic and repeatable deployments, you can add the digests to the image name, through the <image>:<tag>@sha256:<digestValue> format.