podinfo-example

Overview

Podinfo is a tiny web application made with Go that showcases best practices of running microservices in Kubernetes. Podinfo is used by CNCF projects like Flux and Flagger for end-to-end testing and workshops.

Specifications:

• Health checks (readiness and liveness).
• Graceful shutdown on interrupt signals.
• File watcher for secrets and configmaps.
• Instrumented with Prometheus and Open Telemetry.
• Structured logging with zap.
• 12-factor app with viper.
• Fault injection (random errors and latency).
• Swagger docs.
• CUE, Helm and Kustomize installers.
• End-to-End testing with Kubernetes Kind and Helm.
• Kustomize testing with GitHub Actions and Open Policy Agent.
• Multi-arch container image with Docker buildx and Github Actions.
• Container image signing with Sigstore cosign.
• CVE scanning with Trivy.

Please visit the Podinfo documentation page for more details.

Requirements

To complete all steps and deploy the Podinfo sample application, you will need:

1. A DOKS cluster configured and running.
2. Latest Kubectl version for Kubernetes interaction.
3. Git client for interacting with the kubernetes-sample-apps repository.

Deploying to Kubernetes

The kustomization manifest provided in this repository will get you started with deploying the Podinfo application Kubernetes resources.

First, you need to clone this repository:

git clone https://github.com/digitalocean/kubernetes-sample-apps.git

Then, change directory to your local copy:

cd kubernetes-sample-apps

Now, create Podinfo sample application Kubernetes resources using the kubectl kustomize option (-k flag):

kubectl apply -k podinfo-example/kustomize

The output looks similar to:

namespace/podinfo created
service/podinfo created
deployment.apps/podinfo created
horizontalpodautoscaler.autoscaling/podinfo created

If everything went well, you should have a new Kubernetes namespace created named podinfo. Inside the new namespace, you can inspect all resources created by the kustomization manifest from the sample apps repository (all Podinfo application pods should be up and running):

kubectl get all -n podinfo

The output looks similar to:

NAME                          READY   STATUS    RESTARTS   AGE
pod/podinfo-df7bb55d4-dhrpx   1/1     Running   0          107s
pod/podinfo-df7bb55d4-jhq7m   1/1     Running   0          91s

NAME              TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)             AGE
service/podinfo   ClusterIP   10.245.152.36   <none>        9898/TCP,9999/TCP   109s

NAME                      READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/podinfo   2/2     2            2           108s

NAME                                DESIRED   CURRENT   READY   AGE
replicaset.apps/podinfo-df7bb55d4   2         2         2       109s

NAME                                          REFERENCE            TARGETS         MINPODS   MAXPODS   REPLICAS   AGE
horizontalpodautoscaler.autoscaling/podinfo   Deployment/podinfo   <unknown>/99%   2         4         2          109s

Finally, port-forward the podinfo service using kubectl:

kubectl port-forward service/podinfo -n podinfo 9898:9898

Open a web browser and point to localhost:9898. You should see the Podinfo application welcome page:

Cleaning Up

To clean up all Kubernetes resources created by the Podinfo sample application, below command must be used:

kubectl delete ns podinfo

Note:

Kubectl kustomize subcommand has a delete option that can be used - kubectl delete -k podinfo-example/kustomize. But, it won't work well in this case because if the namespace is deleted first then the remaining operations will fail.