Contineous Deployment With Jenkins Gcp Kubernetes

What is Kubernetes Engine?
Kubernetes Engine is GCP's hosted version of Kubernetes - a powerful cluster manager and orchestration system for containers. Kubernetes is an open source project that can run on many different environments—from laptops to high-availability multi-node clusters; from virtual machines to bare metal. As mentioned before, Kubernetes apps are built on Containers - these are lightweight applications bundled with all the necessary dependencies and libraries to run them. This underlying structure makes Kubernetes applications highly available, secure, and quick to deploy—an ideal framework for cloud developers.

What is Jenkins?
Jenkins is an open-source automation server that lets you flexibly orchestrate your build, test, and deployment pipelines. Jenkins allows developers to iterate quickly on projects without worrying about overhead issues that can stem from continuous delivery.

What is Continuous Delivery / Continuous Deployment?
When you need to set up a continuous delivery (CD) pipeline, deploying Jenkins on Kubernetes Engine provides important benefits over a standard VM-based deployment.

When your build process uses containers, one virtual host can run jobs on multiple operating systems. Kubernetes Engine provides ephemeral build executors — these are only utilized when builds are actively running, which leaves resources for other cluster tasks such as batch processing jobs. Another benefit of ephemeral build executors is speed — they launch in a matter of seconds.

Kubernetes Engine also comes pre-equipped with Google's global load balancer, which you can use to automate web traffic routing to your instance(s). The load balancer handles SSL termination and utilizes a global IP address that's configured with Google's backbone network—coupled with your web front, this load balancer will always set your users on the fastest possible path to an application instance.


Lets begin creating a CI/CD piple for kubernetes and GCP

Activate Google Cloud Shell
Google Cloud Shell is a virtual machine that is loaded with development tools.
It offers a persistent 5GB home directory and runs on the Google Cloud. 
Google Cloud Shell provides command-line access to your GCP resources.


Launch gcloud shell

You can list the active account name with this command:
gcloud auth list

List project
gcloud config list project

Set your zone 
gcloud config set compute/zone us-central1-f

Clone repository
git clone https://github.com/GoogleCloudPlatform/continuous-deployment-on-kubernetes.git

cd continuous-deployment-on-kubernetes


Provisioning Jenkins
Creating a Kubernetes cluster

gcloud container clusters create jenkins-cd \
--num-nodes 2 \
--machine-type n1-standard-2 \
--scopes "https://www.googleapis.com/auth/projecthosting,cloud-platform" 

Step takes sometime to complete

Before continuing, confirm that your cluster is running by running the following command:

gcloud container clusters list

Now, get the credentials for your cluster:

gcloud container clusters get-credentials jenkins-cd

Kubernetes Engine uses these credentials to access your newly provisioned cluster—confirm that you can connect to it by running the following command:

kubectl cluster-info


Install Helm
Download and install the helm binary:
wget https://storage.googleapis.com/kubernetes-helm/helm-v2.14.1-linux-amd64.tar.gz

Unzip
tar zxfv helm-v2.14.1-linux-amd64.tar.gz
cp linux-amd64/helm .

Give yourself cluster admin role

kubectl create clusterrolebinding cluster-admin-binding --clusterrole=cluster-admin --user=$(gcloud config get-value account)

Grant Tiller, the server side of Helm, the cluster-admin role in your cluster:
  kubectl create serviceaccount tiller --namespace kube-system
  kubectl create clusterrolebinding tiller-admin-binding --clusterrole=cluster-admin --serviceaccount=kube-system:tille

Initialize Helm. This ensures that the server side of Helm (Tiller) is properly installed in your cluster.

  ./helm init --service-account=tiller
  ./helm update
  
  
Configure and Install Jenkins

se the Helm CLI to deploy the chart with your configuration settings:

./helm install -n cd stable/jenkins -f jenkins/values.yaml --version 1.2.2 --wait

kubectl get pods

Run the following command to setup port forwarding to the Jenkins UI from the Cloud Shell:

export POD_NAME=$(kubectl get pod --selector="app.kubernetes.io/component=jenkins-master,app.kubernetes.io/instance=cd" --output jsonpath='{.items[0].metadata.name}')
kubectl port-forward $POD_NAME 8080:8080 >> /dev/null &

Now, check that the Jenkins Service was created properly:

kubectl get svc


Jenkins chart will automatically create an admin password for you. To retrieve it, run:

printf $(kubectl get secret cd-jenkins -o jsonpath="{.data.jenkins-admin-password}" | base64 --decode);echo

To get to the Jenkins user interface, click on the Web Preview button in cloud shell, then click Preview on port 8080.

Apply the cluster-admin role to the Jenkins service account:

kubectl create clusterrolebinding jenkins-deploy \
    --clusterrole=cluster-admin --serviceaccount=default:cd-jenkins