Application Demo: Gitea

This tutorial explains how to run Gitea on APPUiO Cloud.

If you aren’t familiar with issuing commands on a terminal session, we recommend familiarizing yourself with it before continuing this tutorial.

Requirements

To follow this guide, please make sure that you have the following tools installed:

oc: You can download the OpenShift command directly from APPUiO Cloud, selecting the help menu (marked as a question mark) and selecting the "Command line tools" entry

About the Application

Gitea - Git with a cup of tea

A painless self-hosted Git service.

Gitea is a community managed lightweight code hosting solution written in Go. It’s published under the MIT license.

Step 1: Create a Project

All the following steps are currently only working on the Exoscale APPUiO Zone because of the Application Catalog service availability.

Follow these steps to login to APPUiO Cloud on your terminal:

oc login --server=https://api.${zone}.appuio.cloud:6443

You can find the exact URL of your chosen zone in the APPUiO Cloud Portal.

This command displays a URL on your terminal:

You must obtain an API token by visiting
https://oauth-openshift.apps.${zone}.appuio.cloud/oauth/token/request

Click on the link above and open it in your browser.
Click "Display token" and copy the login command shown as "Log in with this token"

Paste the oc login command on the terminal:

oc login --token=sha256~_xxxxxx_xxxxxxxxxxxxxxxxxxxxxx-xxxxxxxxxx-X \
    --server=https://api.${zone}.appuio.cloud:6443

Create a new project called "[YOUR_USERNAME]-application-demo"
```
oc new-project "[YOUR_USERNAME]-application-demo"
```

Step 2: Deploy the application

To deploy the application we will use standard Kubernetes objects. Save the example YAML Kubernetes resources into a file and apply it with oc apply -f <myfile.yaml>.

First, we need a database:
Database ordering from the VSHN Application Catalog
```
apiVersion: exoscale.appcat.vshn.io/v1
kind: ExoscaleMySQL
metadata:
  name: example-app
spec:
  writeConnectionSecretToRef:
    name: mysql-creds
```
This will create a MySQL DBaaS instance with default settings. See the AppCat docs for more information.

Then we deploy the application:

Application deployment with all other needed resources

apiVersion: apps/v1
kind: Deployment
metadata:
  name: gitea
  labels:
    app.kubernetes.io/name: demo-app
spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: demo-app
  replicas: 1
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app.kubernetes.io/name: demo-app
    spec:
      containers:
        - name: demoapp
          image: quay.io/gpte-devops-automation/gitea:1.19.0
          imagePullPolicy: Always
          ports:
            - name: web
              containerPort: 3000
              protocol: TCP
          resources:
            limits: {}
            requests: {}
          volumeMounts:
            - name: app-data
              mountPath: /data
            - name: db-ca
              mountPath: /srv/db-ca
      volumes:
        - name: app-data
          persistentVolumeClaim:
            claimName: app-data
        - name: db-ca
          secret:
            secretName: mysql-creds
            optional: false
            items:
              - key: ca.crt
                path: ca.crt
---
apiVersion: v1
kind: Service
metadata:
  name: example-app
  labels:
    app.kubernetes.io/name: demo-app
spec:
  type: ClusterIP
  sessionAffinity: None
  ports:
    - name: web
      port: 443
      protocol: TCP
      targetPort: web
  selector:
    app.kubernetes.io/name: demo-app
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: app-data
  labels:
    app.kubernetes.io/name: demo-app
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: "1Gi"
---
apiVersion: route.openshift.io/v1
kind: Route
metadata:
  name: example-app
spec:
  port:
    targetPort: web
  to:
    kind: Service
    name: example-app
    weight: 100
  wildcardPolicy: None
  tls:
    termination: edge
    insecureEdgeTerminationPolicy: Redirect

Now wait until your pod appears with the status "Running":
```
oc get pods --watch
```
Last but not least retrieve the URL of your Gitea instance:
```
oc get route example-app -o jsonpath='{.spec.host}'
```

Configure Gitea

Gitea will display a configuration screen where you need to enter the connection details of your database. You can use this script to display them at the terminal:

#!/usr/bin/env bash

# Database
PGDATABASE=$(oc get secret mysql-creds -ojson | jq -r '.data.MYSQL_DB' | base64 -d)
PGUSER=$(oc get secret mysql-creds -ojson | jq -r '.data.MYSQL_USER' | base64 -d)
PGPASSWORD=$(oc get secret mysql-creds -ojson | jq -r '.data.MYSQL_PASSWORD' | base64 -d)
PGPORT=$(oc get secret mysql-creds -ojson | jq -r '.data.MYSQL_PORT' | base64 -d)
PGHOST=$(oc get secret mysql-creds -ojson | jq -r '.data.MYSQL_HOST' | base64 -d)

echo "Host:          $PGHOST:$PGPORT"
echo "Username:      $PGUSER"
echo "Password:      $PGPASSWORD"
echo "Database name: $PGDATABASE"

Remember to create a default account by expanding the "Administrator Account Settings" section at the bottom of the form!

Click the Install Gitea button. The installation should only take a few seconds.

You can now login to your Gitea instance clicking on the Sign In button on the top right and using the credentials entered during the installation.

This example configuration isn’t meant for a production ready service.

What’s next?

For a production ready service, we recommend the following parts to be implemented and configured:

While the database is already being backed up because it’s a managed service, you should still backup your persistent volume with K8up.
Add some monitoring for your application:
- Monitor HTTP(S) Endpoints Using Blackbox Exporter
- Monitor PVC Disk Usage
Use your own URL with Let’s Encrypt.
Choose appropriate sizing:
- Persistent storage volume size
- Application Catalog DBaaS plan
Maybe you want to use an RWX storage class which allows you to scale your application by running multiple Pods.
Configure proper requests and limits for your Pod.
Use a pinned image version and set the imagePullPolicy to IfNotPresent.
Keep your app up-to-date! Install patches and upgrades as they get available. One way to achieve that, is to use a GitOps style deployment, either push or pull, and leverage the mighty Renovate Bot to keep your image references clean.
Using a Helm Chart for production deployments or Kustomize setup for different stages can be an advantage.

Once you’re done evaluating this example application, cleanup again to not cause any unwanted costs:

oc delete project [YOUR_USERNAME]-application-demo