How to deploy to a (local) Kubernetes cluster using Jenkins - jenkins

Question

This question is somewhat related to one of my previous questions as in it gives a clearer idea on what I am trying to achieve.. This question is about an issue I ran into when trying to achieve the task in that previous question...
I am trying to test if my kubectl works from within the Jenkins container. When I start up my Jenkins container I use the following command:
docker run \
-v /home/student/Desktop/jenkins_home:/var/jenkins_home \
-v $(which kubectl):/usr/local/bin/kubectl \ #bind docker host binary to docker container binary
-v ~/.kube:/home/jenkins/.kube \ #docker host kube config file stored in /.kube directory. Binding this to $HOME/.kube in the docker container
-v /var/run/docker.sock:/var/run/docker.sock \
-v $(which docker):/usr/bin/docker -v ~/.kube:/home/root/.kube \
--group-add 998
-p 8080:8080 -p 50000:50000
-d --name jenkins jenkins/jenkins:lts
The container starts up and I can login/create jobs/run pipeline scripts all no issue.
I created a pipeline script just to check if I can access my cluster like this:
pipeline {
agent any
stages {
stage('Kubernetes test') {
steps {
sh "kubectl cluster-info"
}
}
}
}
When running this job, it fails with the following error:
+ kubectl cluster-info // this is the step
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
error: the server doesn't have a resource type "services"
Thanks!

Answer 1

I'm not getting why there is:
-v $(which kubectl):/usr/local/bin/kubectl -v ~/.kube:/home/jenkins/.kube
/usr/local/bin/kubectl is a kubectl binary and ~/.kube:/home/jenkins/.kube should be the location where the kubectl binary looks for the cluster context file i.e. kubeconfig. First, you should make sure that the kubeconfig is mounted to the container at /home/jenkins/.kube and is accessible to kubectl binary. After appropriate volume mounts, you can verify by creating a session in the jenkins container with docker container exec -it jenkins /bin/bash and test with kubectl get svc. Make sure you have KUBECONFIG env var set in the session with:
export KUBECONFIG=/home/jenkins/.kube/kubeconfig
Before you run the verification test and
withEnv(["KUBECONFIG=$HOME/.kube/kubeconfig"]) {
// Your stuff here
}
In your pipeline code. If it works with the session, it should work in the pipeline as well.
I would personally recommend to create a custom Docker image for Jenkins which will contain kubectl binary and other utilities necessary (such as aws-iam-authenticator for AWS EKS IAM-based authentication) for working with Kubernetes cluster. This creates isolation between your host system binaries and your Jenkins binaries.
Below is the Dockerfile I'm using which contains, helm, kubectl and aws-iam-authenticator.
# This Dockerfile contains Helm, Docker client-only, aws-iam-authenticator, kubectl with Jenkins LTS.
FROM jenkins/jenkins:lts
USER root
ENV VERSION v2.9.1
ENV FILENAME helm-${VERSION}-linux-amd64.tar.gz
ENV HELM_URL https://storage.googleapis.com/kubernetes-helm/${FILENAME}
ENV KUBE_LATEST_VERSION="v1.11.0"
# Install the latest Docker CE binaries
RUN apt-get update && \
apt-get -y install apt-transport-https \
ca-certificates \
curl \
gnupg2 \
software-properties-common && \
curl -fsSL https://download.docker.com/linux/$(. /etc/os-release; echo "$ID")/gpg > /tmp/dkey; apt-key add /tmp/dkey && \
add-apt-repository \
"deb [arch=amd64] https://download.docker.com/linux/$(. /etc/os-release; echo "$ID") \
$(lsb_release -cs) \
stable" && \
apt-get update && \
apt-get -y install docker-ce \
&& curl -o /tmp/$FILENAME ${HELM_URL} \
&& tar -zxvf /tmp/${FILENAME} -C /tmp \
&& mv /tmp/linux-amd64/helm /bin/helm \
&& rm -rf /tmp/linux-amd64/helm \
&& curl -L https://storage.googleapis.com/kubernetes-release/release/${KUBE_LATEST_VERSION}/bin/linux/amd64/kubectl -o /usr/local/bin/kubectl \
&& chmod +x /usr/local/bin/kubectl \
&& curl -L https://amazon-eks.s3-us-west-2.amazonaws.com/1.11.5/2018-12-06/bin/linux/amd64/aws-iam-authenticator -o /usr/local/bin/aws-iam-authenticator \
&& chmod +x /usr/local/bin/aws-iam-authenticator

Answer 2

Kubernetes fails inside jenkins pipeline this was my solution for jenkins installed locally on a windows machine.