This is a step-by-step guide to deploying a project hosted on GitLab.com to Google Cloud, using Auto Deploy.
We made a minimal [Ruby application](https://gitlab.com/gitlab-examples/minimal-ruby-app) to use as an example for this guide. It contains two files:
*`server.rb` - our application. It will start an HTTP server on port 5000 and render “Hello, world!”
*`Dockerfile` - to build our app into a container image. It will use a ruby base image and run `server.rb`
## Fork sample project on GitLab.com
Let’s start by forking our sample application. Go to [the project page](https://gitlab.com/gitlab-examples/minimal-ruby-app) and press the `Fork` button. Soon you should have a project under your namespace with the necessary files.
If you do not already have a Google Cloud account, create one at https://console.cloud.google.com.
Visit the [`Kubernetes Engine`](https://console.cloud.google.com/kubernetes/list) tab and create a new cluster. You can change the name and leave the rest of the default settings. Once you have your cluster running, you need to connect to the cluster by following the Google interface.
## Connect to Kubernetes cluster
You need to have the Google Cloud SDK installed. e.g.
Now go back to the Google interface, find your cluster, and follow the instructions under `Connect to the cluster` and open the Kubernetes Dashboard. It will look something like `gcloud container clusters get-credentials ruby-autodeploy \ --zone europe-west2-c --project api-project-XXXXXXX` and then `kubectl proxy`.
## Copy credentials to GitLab.com project
Once you have the Kubernetes Dashboard interface running, you should visit `Secrets` under the `Config` section. There you should find the settings we need for GitLab integration: ca.crt and token.
You need to copy-paste the ca.crt and token into your project on GitLab.com in the Kubernetes integration page under project `Settings` > `Integrations` > `Project services` > `Kubernetes`. Don't actually copy the namespace though. Each project should have a unique namespace, and by leaving it blank, GitLab will create one for you.
For API URL, you should use the `Endpoint` IP from your cluster page on Google Cloud Platform.
## Expose the application to the internet
In order to be able to visit your application, you need to install an NGINX ingress controller and point your domain name to its external IP address.
### Set up Ingress controller
You’ll need to make sure you have an ingress controller. If you don’t have one, do:
```sh
brew install kubernetes-helm
helm init
helm install --name ruby-app stable/nginx-ingress
```
This should create several services including `ruby-app-nginx-ingress-controller`. You can list your services by running `kubectl get svc` to confirm that.
### Point DNS at Cluster IP
Find out the external IP address of the `ruby-app-nginx-ingress-controller` by running:
```sh
kubectl get svc ruby-app-nginx-ingress-controller -o jsonpath='{.status.loadBalancer.ingress[0].ip}'
```
Use this IP address to configure your DNS. This part heavily depends on your preferences and domain provider. But in case you are not sure, just create an A record with a wildcard host like `*.<your-domain>` pointing to the external IP address you found above.
Use `nslookup minimal-ruby-app-staging.<yourdomain>` to confirm that domain is assigned to the cluster IP.
Visit the home page of your GitLab.com project and press "Set up Auto Deploy" button.
You will be redirected to the "New file" page where you can apply one of the Auto Deploy templates. Select "Kubernetes" to apply the template, then in the file, replace `domain.example.com` with your domain name and make any other adjustments you need.
