deploy-using-helm

Create a helm chart for the app

References:

Create the helm char skeleton
```
 helm create tr-webapp
```
Modify description in file tr-webapp/Chart.yaml:
```
 description: A Helm chart for Kubernetes
```

Comment livenessProbe and readinessProbe sections in file tr-webapp/templates/deployment.yaml:

 #          livenessProbe:
 #            httpGet:
 #              path: /
 #              port: http
 #          readinessProbe:
 #            httpGet:
 #              path: /
 #              port: http

Modify a few variables in file tr-webapp/values.yaml:
- repository: rjrpaz/tr-webapp
- tag: “1.0.0”
- name: “tr-webapp-svc”
Modify service section in file tr-webapp/values.yaml:
```
 service:
   type: NodePort
   port: 8080
```
Modify hosts section in file tr-webapp/values.yaml (change host entry):
```
     - host: hello-world.local
```

Check helm chart integrity:

 [roberto@vmlab01 ]$ helm lint ./tr-webapp
 ==> Linting ./tr-webapp
 [INFO] Chart.yaml: icon is recommended

 1 chart(s) linted, 0 chart(s) failed

To test the app, install the service using this new chart:

 [roberto@vmlab01 ]$ helm install tr-webapp ./tr-webapp
 NAME: tr-webapp
 LAST DEPLOYED: Thu Sep  9 15:30:23 2021
 NAMESPACE: default
 STATUS: deployed
 REVISION: 1
 NOTES:
 1. Get the application URL by running these commands:
 export POD_NAME=$(kubectl get pods -l "app.kubernetes.io/name=tr-webapp,app.kubernetes.io/instance=tr-webapp" -o jsonpath="{.items[0].metadata.name}")
 export CONTAINER_PORT=$(kubectl get pod $POD_NAME -o jsonpath="{.spec.containers[0].ports[0].containerPort}")
 echo "Visit http://127.0.0.1:8080 to use your application"
 kubectl port-forward $POD_NAME 8080:$CONTAINER_PORT

… and run the command provided by previous step:

 export POD_NAME=$(kubectl get pods -l "app.kubernetes.io/name=tr-webapp,app.kubernetes.io/instance=tr-webapp" -o jsonpath="{.items[0].metadata.name}")
 export CONTAINER_PORT=$(kubectl get pod $POD_NAME -o jsonpath="{.spec.containers[0].ports[0].containerPort}")
 kubectl port-forward $POD_NAME 8080:$CONTAINER_PORT

Access to the same url http://localhost:8080 and you should see the same sample webpage as before:
```
 [roberto@vmlab01 ~]$ curl http://127.0.0.1:8080
 Hello World
```
Press Ctrl + C to interrupt the port forwarding

Publishing the chart

References:

https://helm.sh/docs/topics/chart_repository/#github-pages-example

We are going to use github pages as repository for the helm chart.

Create a gh-pages branch in the github repository:
Configure Settings –> pages. Enable gh-pages if needed and configure the root folder that will store the documentation. In this case, the root directory of the project will store the documentation and the package.
Change to root directory for the project and run:
```
 helm package helm/tr-webapp
```
this will create a helm package named tr-webapp-0.1.0.tgz.
Create index file for the package repository
```
 helm repo index . --url http://www.robertopaz.com.ar/deploy-using-helm/
```
this should generate a index.yaml file.
Upload the branch:
```
 git push origin gh-pages
```

Now you can use this as a helm repo:

Add the repo:

 [dxcuser@vmlab01 ~]$ helm repo add tr-webapp https://www.robertopaz.com.ar/deploy-using-helm/
 "tr-webapp" has been added to your repositories

Install the package:

 [dxcuser@vmlab01 ~]$ helm install tr-webapp tr-webapp/tr-webapp

 NAME: tr-webapp
 LAST DEPLOYED: Sun Sep 12 16:52:52 2021
 NAMESPACE: default
 STATUS: deployed
 REVISION: 1
 NOTES:
 1. Get the application URL by running these commands:
 export NODE_PORT=$(kubectl get --namespace default -o jsonpath="{.spec.ports[0].nodePort}" services tr-webapp)
 export NODE_IP=$(kubectl get nodes --namespace default -o jsonpath="{.items[0].status.addresses[0].address}")
 echo http://$NODE_IP:$NODE_PORT

List installed packages:

 [dxcuser@vmlab01 ~]$ helm list
 NAME            NAMESPACE       REVISION        UPDATED                                  STATUS          CHART           APP VERSION
 tr-webapp       default         1               2021-09-12 16:52:52.413712448 -0400 EDT  deployed        tr-webapp-0.1.0 0.1.0

Run last commands suggested from the installation and confirm the app is running:

 [dxcuser@vmlab01 ~]$ export NODE_PORT=$(kubectl get --namespace default -o jsonpath="{.spec.ports[0].nodePort}" services tr-webapp)
 [dxcuser@vmlab01 ~]$ export NODE_IP=$(kubectl get nodes --namespace default -o jsonpath="{.items[0].status.addresses[0].address}")
 [dxcuser@vmlab01 ~]$ echo http://$NODE_IP:$NODE_PORT
 http://192.168.49.2:32086

 [dxcuser@vmlab01 ~]$ curl http://192.168.49.2:32086
 Hello World