How do I set up a pod disruption budget in Kubernetes?

This guide will show you how to set up a Pod Disruption Budget (PDB) in Kubernetes using Pulumi. A PDB ensures that a certain number or percentage of pods in a deployment remain available during voluntary disruptions such as node drains or updates.

Below is a complete Pulumi program written in TypeScript to create a Pod Disruption Budget for a set of pods labeled app: myapp. This PDB specifies that at least one pod must be available at all times.

import * as pulumi from "@pulumi/pulumi";
import * as k8s from "@pulumi/kubernetes";

// Define the namespace
const namespace = new k8s.core.v1.Namespace("my-namespace", {
    metadata: { name: "my-namespace" },
});

// Define the Pod Disruption Budget
const pdb = new k8s.policy.v1.PodDisruptionBudget("myapp-pdb", {
    metadata: {
        name: "myapp-pdb",
        namespace: namespace.metadata.name,
    },
    spec: {
        selector: {
            matchLabels: {
                app: "myapp",
            },
        },
        minAvailable: 1, // Ensure at least 1 pod is always available
    },
});

// Export the namespace and PDB names
export const namespaceName = namespace.metadata.name;
export const pdbName = pdb.metadata.name;

Key Points

• Namespace: We create a Kubernetes namespace to isolate resources.
• Pod Disruption Budget: We define a PDB that ensures at least one pod labeled app: myapp remains available during disruptions.
• Selectors: The PDB uses label selectors to target specific pods.

Summary

In this guide, we set up a Pod Disruption Budget in Kubernetes using Pulumi and TypeScript. This ensures that at least one pod remains available during voluntary disruptions, helping to maintain application availability.