Jenkins build Docker daemon not running on kubernetes cluster - docker

Question

I'm new to Dev Ops and trying to build my code using Jenkins and upload it on the kubernetes cluster which is hosted on the IBM cloud. But when I run the Docker run command in the Jenkins script I keep getting this error. Installed all the latest plugins and
+ docker run hello-world
docker: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?.
Here's the Jenkins script which I don't know is right or wrong. I searched a couple of articles and question. They all were not giving me a positive result.
Tried this Jenkins Docker in Docker on GCP/Kubernetes.
podTemplate(
cloud: "kubernetes",
label:"mypod",
containers:[
containerTemplate(
name:"nodejs",
image:"node",
ttyEnabled:true,
command:'cat',
alwaysPullImage: true,
resourceRequestCpu: '200m',
resourceRequestMemory: '100Mi',
),
containerTemplate(
name:"docker",
image:"",
ttyEnabled:true,
command:'cat',
alwaysPullImage: true,
resourceRequestCpu: '200m',
resourceRequestMemory: '100Mi',
),
containerTemplate(
name:"helm",
image:"alpine/helm",
ttyEnabled:true,
command:'cat',
alwaysPullImage: true,
resourceRequestCpu: '200m',
resourceRequestMemory: '100Mi',
)
],
volumes:[
hostPathVolume(hostPath: '/var/run/docker.sock', mountPath: '/var/run/docker.sock')
]
){
node("mypod"){
def commitId
stage ("Fetch repo"){
checkout scm
commitId = sh(script: 'git rev-parse --short HEAD',returnStdout:true).trim()
}
stage ("Installing packages"){
container("nodejs"){
sh 'npm install'
}
}
stage ("Build"){
container("nodejs"){
sh 'npm run build'
}
}
def repository
stage ("Docker"){
container('docker'){
docker.withRegistry("https://us.icr.io/api","ibm-cloud"){
sh "docker run hello-world"
}
}
}
stage ("Deploy"){
container ("helm"){
sh 'helm version'
}
}
}
}
This is the deployment file of my Jenkins pod
apiVersion: apps/v1
kind: Deployment
metadata:
name: jenkins-uat
labels:
app: jenkins
chart: jenkins-5.0.18
release: jenkins-uat
heritage: Helm
spec:
selector:
matchLabels:
app: jenkins
release: jenkins-uat
template:
metadata:
labels:
app: jenkins
chart: jenkins-5.0.18
release: jenkins-uat
heritage: Helm
spec:
securityContext:
fsGroup: 1001
containers:
- name: jenkins
image: docker.io/bitnami/jenkins:2.235.1-debian-10-r7
imagePullPolicy: "IfNotPresent"
securityContext:
runAsUser: 1001
env:
- name: JENKINS_USERNAME
value: "hlpjenkin"
- name: JENKINS_PASSWORD
valueFrom:
secretKeyRef:
name: jenkins-uat
key: jenkins-password
- name: JENKINS_HOME
value: "/opt/bitnami/jenkins/jenkins_home"
- name: DISABLE_JENKINS_INITIALIZATION
value: "no"
ports:
- name: http
containerPort: 8080
- name: https
containerPort: 8443
livenessProbe:
httpGet:
path: /login
port: http
initialDelaySeconds: 180
periodSeconds: 10
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 6
readinessProbe:
httpGet:
path: /login
port: http
initialDelaySeconds: 30
periodSeconds: 5
timeoutSeconds: 3
successThreshold: 1
failureThreshold: 3
resources:
limits: {}
requests:
cpu: 300m
memory: 512Mi
volumeMounts:
- name: jenkins-data
mountPath: /bitnami/jenkins
volumes:
- name: jenkins-data
persistentVolumeClaim:
claimName: jenkins-uat

Answer 1

So I have installed Jenkins as a container in my k8s cluster :) and managed to reproduce the same error:
docker run --rm hello-world
docker: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?.
See 'docker run --help'.
How to fix it.
In order to fix you definitely need to have access to the Docker on your K8s Node. Very good explanation of how that works was given by jpetazzo.
Technically you do not need "Docker in Docker" (that is the "full Docker setup" in Docker). You just want to be able to run Docker from your CI system, while this CI system itself is in a container. So that that your CI system like Jenkins can start containers.
So when you start your CI container (Jenkins or other), instead of hacking something together with Docker-in-Docker, start it with the access to /var/run/docker.sock on main host.
Below you can see the part of my Yamls that a responsible for that.
That allows my CI container to have access to the Docker socket, and CI container will, therefore, be able to start containers.
Except that instead of starting “child” containers, it will start “sibling” containers, but that is perfectly fine in our context.
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
...
spec:
template:
spec:
containers:
- env:
volumeMounts:
- mountPath: /var/run/docker.sock
name: docker-sock
...
volumes:
- hostPath:
path: /var/run/docker.sock
type: File
name: docker-sock
So in my case, the pipeline I've created produces the following logs:
####pipeline
pipeline {
agent any
stages {
stage('second_stage'){
steps{
sh 'docker run --rm hello-world'
}
}
}
}
####logs
+ docker run --rm hello-world
Hello from Docker!

Answer 2

I had this similar problem and I fixed this by enabling my user to be part of docker group and execute docker. This happens when your user is unable to find docker.
You need follow the post installation steps after installing docker.
Create the docker group
sudo groupadd docker
Add your user to the docker group.
sudo usermod -aG docker $USER
Restart docker service
sudo service docker stop and sudo service docker start
Exit/Logout from current user and Log back in to verify

Answer 3

So I see a couple of problems in your podtemplate.
First of all, for docker container, you didn't specify any image. You should use a docker image in this container. Create your own container with docker installed in it or you can use https://hub.docker.com/r/volaka/ibm-cloud-cli this image. It includes ibmcloud cli, kubectl, helm and docker for kubernetes automation on IBM Cloud.
Second thing is that I think it is related with Jenkins Kubernetes. Once you create a podTemplate in a pipeline, even if you edit the template, sometimes the changes are not seen in the latest pod. I had this kind of error so I deleted and recreated the pipeline with the edited podTemplate. I am saying this because even if you have declared your volume binding in podTemplate, I don't see it in the created pod's yaml. So I recommend you to recreate your pipeline with your final podTemplate.
I have created a detailed walkthrough about how to install, configure and automate Jenkins pipelines on IBM Kubernetes Service. Feel free to check it. https://volaka.gitbook.io/jenkins-on-k8s/