2025-10-15 19:16:27 +02:00

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# Overview
In this demo we will learn the basics of ArgoCD
## Install the School App
```bash
# Setup MongoDB DB in K8s
kubectl create ns schoolapp
helm repo add bitnami https://charts.bitnami.com/bitnami
helm install schoolapp-mongodb --namespace schoolapp \
--set auth.enabled=true \
--set auth.rootUser=schoolapp \
--set auth.rootPassword=mongoRootPass \
bitnami/mongodb
# Add project repo to helm
helm repo add schoolapp https://gitlab.com/api/v4/projects/34240616/packages/helm/stable
# Install the Frontend
helm install frontend -n schoolapp schoolapp/schoolapp-frontend
# Install the API
helm install api -n schoolapp schoolapp/schoolapp-api
# Port forward the frontend
kubectl -n schoolapp port-forward service/frontend 8001:8080
# Port forward the api
kubectl -n schoolapp port-forward service/api 5000:5000
```
## Test the School App
From a browser, go to http://127.0.0.1:8001
## ArgoCD Setup
Now let's get ArgoCD ready for our school app.
## Install ArgoCD
### Install the ArgoCD Server
```bash
kubectl create namespace argocd
kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml
```
Wait until all the pods are running
```bash
watch kubectl get po
```
## Access ArgoCD
### Expose the ArgoCD API Server
```bash
kubectl port-forward svc/argocd-server -n argocd 8002:443
```
### Get the admin password
```bash
kubectl -n argocd get secret argocd-initial-admin-secret -o jsonpath="{.data.password}" | base64 -d; echo
```
For this demo, I won't change the password, but you should go ahead and change the password and remove the K8s secret.
### Login using the UI
You can log in to the UI by opening a browser window and going to https://127.0.0.1:8002
```bash
username: admin
password: <THE_PASSWORD_YOU_GOT_ABOVE>
```
## School App Example with ArgoCD and Hardcoded Secrets
Now let's see how to use a GitOps approach with ArgoCD to run our school app.
## Delete the Current School App
```bash
kubectl delete ns schoolapp
```
## Create the School App Application in ArgoCD
```bash
kubectl apply -f argocdSchoolApp.yaml
```
## Test the School App with ArgoCD
```bash
# Port forward the frontend
kubectl port-forward service/frontend 8001:8080 -n schoolapp
# Port forward the api
kubectl port-forward service/api 5000:5000 -n schoolapp
```
Try creating and deleting a course and check the logs of the api pod.
```bash
kubectl logs -n schoolapp -f $(kubectl get pods --template '{{range .items}}{{.metadata.name}}{{end}}' --selector=app=api) -c api
```
## Making a Change in Git
Now let's see how Argo CD can detect drift between the live state and the target state. Let's make a simple change in our Git repo for the called schoolapp-subchart/values.yaml. Change the mongodb.auth.enabled value from true to false.
```yaml
mongodb:
auth:
enabled: false
rootUser: 'schoolapp'
rootPassword: 'mongoRootPass'
```
Then commit and push your changes.