Installing Jenkins inside Kubernetes

Step-by-step guide how to install Jenkins in the Kubernetes cluster and run Jenkins agents inside that cluster.

For minikube install ingress controller with following command:

minikube start -n 2

minikube addons enable ingress

Create Kubernetes namespace

kubectl create namespace jenkins

Apply service account configuration

kubecl apply -f config/jenkins/service-account.yaml

Apply Jenkins deployment configuration

kubectl apply -f config/jenkins/jenkins.yaml

Apply Jenkins ingress configuration

kubectl apply -f jenkins-ingress.yaml

Get minikube ip address and add jenkins.example.com to /etc/hosts file

echo "$(minikube ip) jenkins.example.com" >> /etc/hosts

Log into Jenkins and create new user/or update password for 'admin'

Install 'Kubernetes' Jenkins plugin

Tune up Kubernetes plugin

Navigate to 'Manage Jenkins' -> 'Manage Nodes and Clouds' -> 'Configure Clouds'

Press 'Add new cloud' and select 'Kubernetes'

Press 'Kubernetes Cloud details...' button to configure Kubernetes plugin

1. Under 'Kubernetes Namespace' write the namespace that was previously configured. In my case it is 'jenkins'. Press 'Test Connection' button - 'Connected to Kubernetes vX.XX.XX' should appear.

2. Config 'Jenkins URL' field. It should combined from following info: http://<service-name>.<namespace>.svc.cluster.local:8080. To check service name just issue following command: kubectl get svc -n jenkins. In my case it looks as: http://jenkins-service.jenkins.svc.cluster.local:8080

3. Under 'Pod Labels' section press 'Add Pod Label' button and select 'Pod Label'. Fill 'Key' - 'Jenkins' and 'Value' - 'agent'

4. Under 'Pod Templates' press 'Add Pod Template' button and 'Pod Template Details...' button. Fill the following fields with info:

   • 'Name' - 'kube-agent'
   • 'Namespace' - 'jenkins'
   • 'Labels' - 'kubeagent'

5. Under 'Containers' press 'Add Container' button and select 'Container Template'. Fill 'Name' - 'jnlp' and 'Docker image' - 'jenkins/inbound-agent:latest'. Remove values from 'Command to run' and 'Arguments to pass to the command' fields.

Now Jenkins will build jobs that have label 'kubeagent' inside container.

Apply prometheus and grafana configs in the next order

Prometheus:

clusterRole.yaml

config-map.yaml

prometheus-deployment.yaml

prometheus-service.yaml

prometheus-ingress.yaml

Grafana:

grafana-datasource-config.yaml

grafana-deployment.yaml

grafana-service.yaml

grafana-ingress.yaml

Add ingress addresses to /etc/hosts

echo "$(minikube ip) prometheus.example.com" >> /etc/hosts

echo "$(minikube ip) grafana.example.com" >> /etc/hosts

Verify Services

http://jenkins.example.com

http://prometheus.example.com

http://grafana.example.com