a5e57583b5
- apps/apps/podinfo.yaml: ArgoCD Application for podinfo - manifests/apps/podinfo/: namespace, deployment (6.6.2), service - docs/01-argocd-bootstrap.md: Exercise 01 participant guide - docs/02-deploy-podinfo.md: Exercise 02 participant guide
158 lines
3.7 KiB
Markdown
158 lines
3.7 KiB
Markdown
# Exercise 02 — Deploy podinfo via GitOps
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**Time**: ~30 min
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**Goal**: Deploy a real application to the cluster purely through Git — no `kubectl apply`.
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---
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## What you'll learn
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- How adding an ArgoCD `Application` manifest to Git is the only deploy action needed
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- How to read ArgoCD sync status and application health
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- The GitOps feedback loop: commit → push → ArgoCD detects change → cluster updated
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---
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## Prerequisites
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Exercise 01 complete: ArgoCD is running and the root app is Synced.
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---
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## Background: what is podinfo?
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`podinfo` is a tiny Go web app by Stefan Prodan (ArgoCD's author) — often used in
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Kubernetes demos. It shows its own version number, has `/healthz` and `/readyz`
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endpoints, and looks good in a browser. No external dependencies, no secrets needed.
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---
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## Steps
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### 1. Understand what already exists
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The repo already contains the podinfo manifests. Take a look:
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```bash
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ls manifests/apps/podinfo/
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# namespace.yaml deployment.yaml service.yaml
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```
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Open `manifests/apps/podinfo/deployment.yaml` and find the image tag:
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```yaml
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image: ghcr.io/stefanprodan/podinfo:6.6.2
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```
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This is version **6.6.2**. Remember it — you'll upgrade it later.
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---
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### 2. Create the ArgoCD Application
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This is the only thing you need to "deploy" the app — tell ArgoCD to watch the manifests:
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```bash
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cat apps/apps/podinfo.yaml
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```
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You'll see it points ArgoCD at `manifests/apps/podinfo/` in this repo. The app
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already exists in the repo, so ArgoCD's root app will pick it up automatically.
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Check ArgoCD now — you should already see a **podinfo** application appearing.
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> **The GitOps point**: You didn't run any `kubectl apply` for podinfo. You committed
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> `apps/apps/podinfo.yaml` to Git, and ArgoCD synced it. That's the entire workflow.
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---
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### 3. Watch it sync
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```bash
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kubectl get application podinfo -n argocd -w
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```
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Wait until you see `Synced` and `Healthy`. Then:
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```bash
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kubectl get pods -n podinfo
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# NAME READY STATUS RESTARTS AGE
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# podinfo-xxxxxxxxx-xxxxx 1/1 Running 0 30s
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```
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---
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### 4. Verify the app is working
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Port-forward to test locally (inside the VM):
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```bash
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kubectl port-forward svc/podinfo -n podinfo 9898:80
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```
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In another terminal (or using curl inside the VM):
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```bash
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curl http://localhost:9898
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# {"hostname":"podinfo-xxx","version":"6.6.2", ...}
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```
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You can see `"version":"6.6.2"` — that matches the image tag in `deployment.yaml`.
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---
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### 5. Make a GitOps change
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Let's change the UI color to prove the loop works.
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Edit `manifests/apps/podinfo/deployment.yaml` and change:
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```yaml
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value: "#6C48C5"
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```
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to any hex color you like, e.g.:
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```yaml
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value: "#2ecc71"
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```
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Commit and push:
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```bash
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git add manifests/apps/podinfo/deployment.yaml
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git commit -m "chore: change podinfo UI color"
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git push
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```
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Within ~3 minutes (ArgoCD's default poll interval) you'll see the pod restart and
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the new color appear. You can also click **Refresh** in the ArgoCD UI to trigger
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an immediate sync.
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---
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## Expected outcome
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```
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NAME SYNC STATUS HEALTH STATUS
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podinfo Synced Healthy
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```
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```bash
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curl http://localhost:9898 | jq .version
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# "6.6.2"
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```
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---
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## Troubleshooting
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| Symptom | Fix |
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| Application stuck in "Progressing" | `kubectl describe pod -n podinfo` — usually image pull |
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| `ImagePullBackOff` | Image was pre-pulled; run `kubectl get events -n podinfo` |
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| ArgoCD shows OutOfSync after push | Click **Refresh** or wait 3 min for next poll |
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---
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## What's next
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podinfo is running but only accessible via port-forward. In Exercise 03 you'll
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expose it on your LAN using MetalLB (a real load balancer) and Ingress-Nginx,
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so you can reach it from your laptop's browser without any port-forward.
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