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Running PodInfo

Updated Aug 19, 2022 ·

Overview​

Podinfo is a small web application used to test, demo, and learn Kubernetes and GitOps tools like FluxCD.

  • Shows pod details through a web UI
  • Supports health checks and horizontal scaling
  • Good for testing GitOps flows with FluxCD

Pre-requisites​

Project Structure​

If you followed the steps in setting up Flux, your project directory should have the following files:

$ tree
.
├── README.md
└── clusters
    └── dev
        └── flux-system
            ├── gotk-components.yaml
            ├── gotk-sync.yaml
            └── kustomization.yaml

3 directories, 4 files

This repository contains the Flux CD configuration files, but it doesn't necessarily need to contain the application files as well. _To organize the manifests, we will create folders for each lab, along with their respective kustomization.yaml file.

For this lab, create the podinfo directory:

mkdir clusters/dev/podinfo  
```_

## `podinfo-repo.yaml`

To use a different repository which contain the application files, create a new config file which tells Flux to monitor a new Git repository:

```yaml 
# clusters/dev/podinfo/podinfo-repo.yaml 
apiVersion: source.toolkit.fluxcd.io/v1
kind: GitRepository
metadata:
  name: podinfo
  namespace: flux-system
spec:
  interval: 30s       ## how frequent flux will sync
  url: https://github.com/stefanprodan/podinfo.git
  ref:
    branch: master
info

This only tells FluxCD to watch the repo, not what to do with it.

podinfo-customization.yaml​

This tells FluxCD how to apply the files in the repo. You can use any filename, just make sure that it's descriptive.

# clusters/dev/podinfo/podinfo-customization.yaml
apiVersion: kustomize.toolkit.fluxcd.io/v1
kind: Kustomization
metadata:
  name: podinfo
  namespace: flux-system
spec:
  interval: 5m0s
  path: ./kustomize
  prune: true
  sourceRef:
    kind: GitRepository
    name: podinfo
  targetNamespace: default

This file links to the repo and tells FluxCD where and how to apply the resources.

Add the Files in kustomization.yaml​

This ensures that Flux also watches for the podinfo manifests.

# clusters/dev/podinfo/kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- gotk-components.yaml
- gotk-sync.yaml
- podinfo-repo.yaml
- podinfo-customization.yaml

Pushing the Files to Git​

Now commit and push the changes:

git add -A
git commit -m "Add podinfo repo and customization"
git push

If FluxCD made earlier commits, pull them first:

git pull --rebase

Then push your changes again if needed.

FluxCD will pick up the changes and apply them in the next sync cycle.

Checking That It Worked​

You can check if FluxCD synced your customization using:

flux get kustomizations --watch

If it says Ready=True and Suspended=False, the deployment was successful.

NAME            REVISION                SUSPENDED       READY   MESSAGE

flux-system     main@sha1:8357455f      False           True    Applied revision: main@sha1:8357455f
flux-system     main@sha1:8357455f      False   Unknown Reconciliation in progress
flux-system     main@sha1:8357455f      False   Unknown Reconciliation in progress
podinfo         False   False   waiting to be reconciled
podinfo         False   False   waiting to be reconciled
flux-system     main@sha1:8357455f      False   True    Applied revision: main@sha1:0cceaab8
flux-system     main@sha1:0cceaab8      False   True    Applied revision: main@sha1:0cceaab8
podinfo         False   False   Source artifact not found, retrying in 30s
podinfo         False   Unknown Reconciliation in progress
podinfo         False   True    Applied revision: master@sha1:fb3b01be
podinfo master@sha1:fb3b01be    False   True    Applied revision: master@sha1:fb3b01be
podinfo master@sha1:fb3b01be    False   Unknown Reconciliation in progress
podinfo master@sha1:fb3b01be    False   True    Applied revision: master@sha1:fb3b01be

Now verify that the pods and the service are created:

$ kubectl get pods -n default
NAME                       READY   STATUS    RESTARTS   AGE
podinfo-5d9db9b467-9h26p   1/1     Running   0          3h47m
podinfo-5d9db9b467-mldhr   1/1     Running   0          3h47m 

$ kubectl get svc -n default
NAME         TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)
   AGE
kubernetes   ClusterIP   10.96.0.1      <none>        443/TCP
   19h
podinfo      ClusterIP   10.96.103.28   <none>        9898/TCP,9999/TCP   3h52m

To test the app, run:

kubectl port-forward svc/podinfo 9898:9898 --address 0.0.0.0

Then go to http://your-vm-ip:9898 in your browser. You’ll see the Podinfo web interface.

If you're running directly on your machine, you can go to localhost:9898: