For full documentation, visit this Medium post.
Provision a DigitalOcean-managed Kubernetes cluster and deploy a NodeJs application to production using GitLab Auto DevOps with Prometheus monitoring, in less time than it takes to walk to your nearest bakery.
You'll need to :
- Register for an account on DigitalOcean and generate a personal access token
- Register for an account on GitLab
- Install Docker and git on your machine
Be aware that the following commands will set up a DigitalOcean-managed cluster with 2 nodes (1vCPU, 2GB) and some extra resources like a Load Balancer, which will be billed by DigitalOcean. Check the pricing.
Clone this repository (which is based on https://github.com/snormore/doks-examples):
git clone [email protected]:ehemmerlin/gitlab-dok8s
cd gitlab-dok8s
Run a golang Docker container by typing:
docker run -it -v "$PWD":/usr/src/myapp -w /usr/src/myapp golang:1.13 bash
Inside the docker container, launch the setup script : it will install jq, kubectl and doctl inside a docker container then ask for your access key to login to DigitalOcean.
script/setup
Enter your DigitalOcean access token.
Note: you can also set the token by replacing "your_DO_token" with your DigitalOcean access token in the following command, before lauching the setup script.
docker run -it --env=DIGITALOCEAN_ACCESS_TOKEN="your_DO_token" -v "$PWD":/usr/src/myapp -w /usr/src/myapp golang:1.13 bash
Inside the docker container, launch the up script : it will create a DigitalOcean-managed Kubernetes cluster with default name gitlab-demo based on Adding an existing Kubernetes cluster to Gitlab to retrieve the API URL, CA certificate and Service Token used to integrate this Kubernetes cluster with GitLab.
script/up
You can specify a cluster name with:
script/up my-cluster-name
Note: If later you need the API URL, CA certificate or Service Token, run this script again with the same cluster name.
Create a new group within gitlab.com : https://gitlab.com/groups/new
Give the group a name and click on Create group.
In the menu panel on the left hand side of the group page, select Kubernetes and click on Add Kubernetes cluster.
Select Add existing cluster and give the cluster a name, then fill in the fields you got from the previous step (see the Kubernetes part above) : API URL, CA certificate and Service Token.
Enable both RBAC-enabled cluster and GitLab-managed cluster (if asked leave the Project namespace prefix blank) and click on Add Kubernetes cluster.
Once you add the cluster to GitLab, a list of applications to install into the cluster will appear. The first of these is Helm Tiller. Go ahead and click on Install to add it to the cluster.
The second one to install is Ingress. It will provision a DigitalOcean Load Balancer. Once installed copy the value of the Ingress Endpoint that appears then install Prometheus which is the third application we need.
Once these three applications are installed, scroll to the top of the page and locate the Base domain field. Enter the value of the Ingress Endpoint you copied, followed by .nip.io and click on Save changes.
Every project you'll add to this group can now be deployed in your Kubernetes cluster if you enable Auto DevOps on this project. So let's give it a try!
Create a new project within gitlab.com : https://gitlab.com/projects/new
On the New Project page, select the Create from template tab. This will provide you with a list of template projects to use. Select NodeJS Express (which includes CI/CD with Auto DevOps feature) by clicking on Use template. Give the project a name and make sure you select the Project URL of the group you created. Click Create project when you are finished.
Next, in the navigation panel, select Settings > CI/CD. Expand the Auto DevOps section, and check the Default to Auto DevOps pipeline box. Leave the Deployment strategy set to Continuous deployment to production.
A new pipeline is created and a job is starting. In the navigation panel, select CI/CD > Pipelines to see this pipeline.
After the pipeline has finished, in the navigation panel, select Operations > Environments. Next to production on the right hand side, click on the first icon (Open live environment) to open your newly deployed NodeJS Express application, then click on the icon next to the right (Monitoring) to monitor your Kubernetes cluster using Prometheus.
Congratulations! You have just connected GitLab’s Auto DevOps with a DigitalOcean-managed Kubernetes cluster monitored by Prometheus.
In the navigation panel of the group you created, select Operations > Kubernetes and select the name of your cluster. Uninstall Ingress to remove the DigitalOcean Load Balancer which was created. It can take some time at this step, so grab a cup of tea and refresh the page if needed. Then, scroll to the bottom of the page and expand Advanced settings. Under Remove Kubernetes cluster integration click Remove integration. Confirm by clicking Ok.
Optionally delete the group you created (it will also delete the project): in the navigation panel of the group you created, select Settings > General, scroll to the bottom of the page and expand Path, transfer, remove then select Remove group and confirm its name before clicking Confirm.
Inside the Docker container you started at the beginning, launch the down script : it removes the cluster:
script/down
You can specify a cluster name by typing (be careful if you used your own DigitalOcean-managed Kubernetes cluster in the first step because the following command will remove it!):
script/down my-cluster-name
Note: if for some reason you exited the Docker container prematurely, go to the Getting started - Kubernetes section above to run it again. You'll need to enter your DigitalOcean access token again.
All the provisioned ressources have now been deleted.
To log out of the golang Docker container type:
exit
Everything has now been cleaned up.
To control this Kubernetes cluster using kubectl, run the following command in the Docker container (if you exited it, go to the Getting started - Kubernetes section above to run it again):
export KUBECONFIG="tmp/<your-cluster-name>-kubeconfig.yaml"
Note: by default the cluster name is : gitlab-demo
Now you can run all the kubectl commands you want:
kubectl get pods --all-namespaces
kubectl config set-context --current --namespace=gitlab-managed-apps
kubectl logs pod tiller-deploy-xxxx-yyyy # depending on the name of the tiller deploy pod