CloudNativePG Recipe 1 - Setting up your local playground in minutes

Dive into the world of running PostgreSQL in Kubernetes with CloudNativePG in this inaugural guide. Follow along as we walk you through the process of setting up a disposable local cluster using kind. Gain insights into creating PostgreSQL clusters, installing CloudNativePG, and leveraging the cnpg plugin for kubectl. Wrap up your journey by tidying up your local cluster. Whether you’re a developer or a DBA, this foundational guide provides a launchpad for your future CloudNativePG explorations with a fully open source stack.

Ciao! Welcome to my inaugural recipe on running Postgres in Kubernetes with CloudNativePG: setting up your local playground.

The objective here is to effortlessly guide you through the process of establishing a disposable local Kubernetes cluster on your laptop using kind. While other solutions like Minikube or k3d exist, kind stands out as my preferred choice. It’s lightweight, supports multiple-node Kubernetes clusters, and is versatile enough to be employed in any environment, including CI/CD pipelines. kind is compatible with Linux, macOS, and Windows, and it holds the distinction of being a CNCF certified conformant installer of Kubernetes.

To get started, install kind on your laptop by following the “Quickstart”. Since you’ll be interacting with a Kubernetes cluster, it’s crucial to have kubectl installed as well. Now, let’s dive right in!

Create Your First Kubernetes Cluster #

Start by confirming your kind installation using the following command:

kind version

On my laptop, as of the time of writing, the output is kind v0.22.0 go1.21.7 darwin/amd64.

Now, proceed to establish your initial local Kubernetes cluster for CloudNativePG with:

kind create cluster --name cnpg

Upon execution, you’ll observe the following output:

Creating cluster "cnpg" ...
 ✓ Ensuring node image (kindest/node:v1.29.2) 🖼
 ✓ Preparing nodes 📦
 ✓ Writing configuration 📜
 ✓ Starting control-plane 🕹️
 ✓ Installing CNI 🔌
 ✓ Installing StorageClass 💾
Set kubectl context to "kind-cnpg"
You can now use your cluster with:

kubectl cluster-info --context kind-cnpg

Unsure about the next steps? 😅 Check out https://kind.sigs.k8s.io/docs/user/quick-start/

There you have it – the cnpg Kubernetes cluster is now operational within containers. To confirm, run:

kind get clusters

Congratulations on successfully creating your local Kubernetes environment!

There’s more … #

By default, kind generates a Kubernetes cluster with a single node. If you’re eager to experiment with multiple nodes, simulating the distribution of PostgreSQL instances, explore the “Nodes” section in the kind documentation for detailed insights and configuration options.

Install CloudNativePG #

Now that our local Kubernetes playground is set up, let’s explore the installation of CloudNativePG.

To deploy the latest stable version, refer to the CloudNativePG documentation for instructions on installing the operator via Kubernetes manifests.

For instance, to install version 1.22.2, the latest available at the time of writing, use the following command:

kubectl apply --server-side -f \
  https://raw.githubusercontent.com/cloudnative-pg/cloudnative-pg/release-1.22/releases/cnpg-1.22.2.yaml

This command creates a Deployment resource named cnpg-controller-manager within the cnpg-system namespace of your Kubernetes cluster. The deployment should complete in a few seconds, and you can monitor its progress with:

kubectl get deployment -n cnpg-system cnpg-controller-manager

There’s more … #

For those who are as adventurous as our maintainers, you can install the latest development snapshot from the CloudNativePG trunk (yes, we embrace trunk-based development at CloudNativePG) using the following command:

curl -sSfL \
  https://raw.githubusercontent.com/cloudnative-pg/artifacts/main/manifests/operator-manifest.yaml \
  | kubectl apply --server-side -f -

Feel free to explore different versions or dive into the latest developments!

Create Your First PostgreSQL Cluster #

With CloudNativePG successfully installed in your local cluster, creating your initial 3-instance PostgreSQL cluster is a breeze.

Let’s utilize the basic cluster-example file provided by CloudNativePG for evaluation purposes. The YAML content is concise, under 10 lines, and adheres to the convention over configuration paradigm embraced by CloudNativePG. This default configuration should seamlessly work for most use cases, and all available options are detailed in the API reference, giving you the flexibility to override any of them.

Here’s a snippet of the YAML file:

apiVersion: postgresql.cnpg.io/v1
kind: Cluster
metadata:
  name: cluster-example
spec:
  instances: 3

  storage:
    size: 1Gi

Deploying this cluster, like any other Kubernetes resource, is a one-liner using the kubectl apply command:

kubectl apply -f \
  https://cloudnative-pg.io/documentation/current/samples/cluster-example.yaml

Monitor the progress with kubectl get pods -w.

Once CloudNativePG creates the first instance (cluster-example-1), it promptly clones the first replica (cluster-example-2) and immediately follows up with the second replica (cluster-example-3). This process typically takes around a minute.

Verify the Cluster resource with:

kubectl get cluster cluster-example

On my laptop, the output is:

NAME              AGE     INSTANCES   READY   STATUS                     PRIMARY
cluster-example   4m18s   3           3       Cluster in healthy state   cluster-example-1

Congratulations! You now have your first PostgreSQL cluster up and running with CloudNativePG.

The cnpg plugin for kubectl #

CloudNativePG eschews the need for a standalone command line interface (CLI) and seamlessly integrates with kubectl through its dedicated plugin known as cnpg. This plugin facilitates a direct interface with CloudNativePG deployments using the concise kubectl cnpg command.

Installation of the plugin offers flexibility through various methods, including package installations outlined in the CloudNativePG documentation.

We strongly endorse the cnpg plugin, with one notable advantage being the inclusion of the cnpg status command.

Once the plugin is installed, execute the following command to experience its capabilities firsthand:

kubectl cnpg status cluster-example

This command typically yields output similar to:

Cluster Summary
Name:                cluster-example
Namespace:           default
System ID:           7342047578820919323
PostgreSQL Image:    ghcr.io/cloudnative-pg/postgresql:16.1
Primary instance:    cluster-example-1
Primary start time:  2024-03-21 08:14:28 +0000 UTC (uptime 14m32s)
Status:              Cluster in healthy state
Instances:           3
Ready instances:     3
Current Write LSN:   0/8000000 (Timeline: 1 - WAL File: 000000010000000000000007)

Certificates Status
Certificate Name             Expiration Date                Days Left Until Expiration
----------------             ---------------                --------------------------
cluster-example-ca           2024-06-01 08:09:01 +0000 UTC  89.99
cluster-example-replication  2024-06-01 08:09:01 +0000 UTC  89.99
cluster-example-server       2024-06-01 08:09:01 +0000 UTC  89.99

Continuous Backup status
Not configured

Physical backups
No running physical backups found

Streaming Replication status
Replication Slots Enabled
Name               Sent LSN   Write LSN  Flush LSN  Replay LSN  Write Lag  Flush Lag  Replay Lag  State      Sync State  Sync Priority  Replication Slot
----               --------   ---------  ---------  ----------  ---------  ---------  ----------  -----      ----------  -------------  ----------------
cluster-example-2  0/8000000  0/8000000  0/8000000  0/8000000   00:00:00   00:00:00   00:00:00    streaming  async       0              active
cluster-example-3  0/8000000  0/8000000  0/8000000  0/8000000   00:00:00   00:00:00   00:00:00    streaming  async       0              active

Unmanaged Replication Slot Status
No unmanaged replication slots found

Managed roles status
No roles managed

Tablespaces status
No managed tablespaces

Instances status
Name               Database Size  Current LSN  Replication role  Status  QoS         Manager Version  Node
----               -------------  -----------  ----------------  ------  ---         ---------------  ----
cluster-example-1  29 MB          0/8000000    Primary           OK      BestEffort  1.22.2           cnpg-control-plane
cluster-example-2  29 MB          0/8000000    Standby (async)   OK      BestEffort  1.22.2           cnpg-control-plane
cluster-example-3  29 MB          0/8000000    Standby (async)   OK      BestEffort  1.22.2           cnpg-control-plane

This tool becomes indispensable as it provides essential insights into your CloudNativePG deployment. Moreover, a myriad of other commands is at your disposal. For a comprehensive list, refer to the documentation or simply type kubectl cnpg help.

Cleanup #

As we conclude, let’s maintain orderliness by responsibly removing the Kubernetes cluster recently created from your local container engine platform. This step adheres to our standard practice, mirrored in our CI/CD pipelines for end-to-end (E2E) testing in CloudNativePG.

Execute the following command to gracefully delete the cnpg cluster in kind:

kind delete cluster --name cnpg

Wishing you smooth sailing!

Conclusions #

I trust the provided information has armed you with the knowledge to venture into running PostgreSQL in Kubernetes with CloudNativePG. This recipe stands as a valuable reference in the blog, serving as a compass for future explorations into specific CloudNativePG topics.

Stay tuned for upcoming recipes! Don’t forget to subscribe to my LinkedIn and X channels for the latest updates.

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