https://github.com/phenixblue/k8s-pdb-demo

A Demo of Kubernetes Pod Disruption Budgets
https://github.com/phenixblue/k8s-pdb-demo

budget demo disruption example k8s kubernetes pdb

Last synced: 4 months ago
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A Demo of Kubernetes Pod Disruption Budgets

README

# PDB Demo

This is a demo to show the configuration and functionality of a Kubernetes PDB (Pod Disruption Budget).

## Setup

- Open 3 terminals with the appropriate KUBECONFIG context set

- 1 for interactive work

- Create Namespace

```
$ kubectl create ns pdb-test
```

- Deploy workload

```
$ kubectl apply -f pdb-tester-deploy.yaml -n pdb-test
```

- Deploy PDB

```
$ kubectl apply -f pdb-tester-pdb.yaml -n pdb-test
```

- 1 for watching the pods

```
$ watch kubectl get pods -n pdb-test -o wide
```

![kubectl get pods Screen Shot](./images/pdb-deployment-pods.png)

- 1 for watching the PDB

```
$ watch kubectl get pdb -n pdb-test pdb-tester
```

![kubectl get pdb Screen Shot](./images/pdb-info.png)

## Walkthrough

- Show Sample workload with liveness/readiness probe

```
$ kubectl get deploy -n pdb-test pdb-tester -o yaml
```

- Show PDB configuration

```
$ kubectl get pdb -n pdb-test pdb-tester -o yaml
```

- Show Pods running across different nodes

```
$ kubectl get pods -n pdb-test -o wide
```

- Show how a single node drain affects the workload

```
$ kubectl drain --ignore-daemonsets --delete-local-data
```

- Watching secondary windows showing the pod recreation and wait for probes

- Watch PDB metrics update based on currently unavailable pods

- Show concecutive drain operations being blocked by PDB

```
$ kubectl drain --ignore-daemonsets --delete-local-data; sleep 5; k drain --ignore-daemonsets --delete-local-data
```

![kubectl drain Screen Shot](./images/node-drain-blocked.png)