kubernetes pull of jenkins image giving Imagepullbackoff - docker

Question

Trying to pull jenkins image using helm install stable/jenkins --values jenkins.values --name jenkins
to into my local cluster,but every time, when i do build pod its gives the error as following.
`
[root#kube-master tmp]# kubectl describe pod newjenkins-84cd855fb6-mr9rm
Name: newjenkins-84cd855fb6-mr9rm
Namespace: default
Priority: 0
Node: worker-node2/192.168.20.56
Start Time: Thu, 14 May 2020 14:58:13 +0500
Labels: app.kubernetes.io/component=jenkins-master
app.kubernetes.io/instance=newjenkins
app.kubernetes.io/managed-by=Tiller
app.kubernetes.io/name=jenkins
helm.sh/chart=jenkins-1.16.0
pod-template-hash=84cd855fb6
Annotations: checksum/config: 70d4b49bc5cd79a1a978e1bbafdb8126f8accc44871772348fd481642e33cffb
Status: Pending
IP:
IPs: <none>
Controlled By: ReplicaSet/newjenkins-84cd855fb6
Init Containers:
copy-default-config:
Container ID:
Image: jenkins/jenkins:lts
Image ID:
Port: <none>
Host Port: <none>
Command:
sh
/var/jenkins_config/apply_config.sh
State: Waiting
Reason: PodInitializing
Ready: False
Restart Count: 0
Limits:
cpu: 2
memory: 4Gi
Requests:
cpu: 50m
memory: 256Mi
Environment:
ADMIN_PASSWORD: <set to the key 'jenkins-admin-password' in secret 'newjenkins'> Optional: false
ADMIN_USER: <set to the key 'jenkins-admin-user' in secret 'newjenkins'> Optional: false
Mounts:
/tmp from tmp (rw)
/usr/share/jenkins/ref/secrets/ from secrets-dir (rw)
/var/jenkins_config from jenkins-config (rw)
/var/jenkins_home from jenkins-home (rw)
/var/jenkins_plugins from plugin-dir (rw)
/var/run/secrets/kubernetes.io/serviceaccount from newjenkins-token-jmfsz (ro)
Containers:
jenkins:
Container ID:
Image: jenkins/jenkins:lts
Image ID:
Ports: 8080/TCP, 50000/TCP
Host Ports: 0/TCP, 0/TCP
Args:
--argumentsRealm.passwd.$(ADMIN_USER)=$(ADMIN_PASSWORD)
--argumentsRealm.roles.$(ADMIN_USER)=admin
--httpPort=8080
State: Waiting
Reason: PodInitializing
Ready: False
Restart Count: 0
Limits:
cpu: 2
memory: 4Gi
Requests:
cpu: 50m
memory: 256Mi
Liveness: http-get http://:http/login delay=90s timeout=5s period=10s #success=1 #failure=5
Readiness: http-get http://:http/login delay=60s timeout=5s period=10s #success=1 #failure=3
Environment:
POD_NAME: newjenkins-84cd855fb6-mr9rm (v1:metadata.name)
JAVA_OPTS:
JENKINS_OPTS:
JENKINS_SLAVE_AGENT_PORT: 50000
ADMIN_PASSWORD: <set to the key 'jenkins-admin-password' in secret 'newjenkins'> Optional: false
ADMIN_USER: <set to the key 'jenkins-admin-user' in secret 'newjenkins'> Optional: false
Mounts:
/tmp from tmp (rw)
/usr/share/jenkins/ref/plugins/ from plugin-dir (rw)
/usr/share/jenkins/ref/secrets/ from secrets-dir (rw)
/var/jenkins_config from jenkins-config (ro)
/var/jenkins_home from jenkins-home (rw)
/var/run/secrets/kubernetes.io/serviceaccount from newjenkins-token-jmfsz (ro)
Conditions:
Type Status
Initialized False
Ready False
ContainersReady False
PodScheduled True
Volumes:
plugins:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit: <unset>
tmp:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit: <unset>
jenkins-config:
Type: ConfigMap (a volume populated by a ConfigMap)
Name: newjenkins
Optional: false
secrets-dir:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit: <unset>
plugin-dir:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit: <unset>
jenkins-home:
Type: PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace)
ClaimName: newjenkins
ReadOnly: false
newjenkins-token-jmfsz:
Type: Secret (a volume populated by a Secret)
SecretName: newjenkins-token-jmfsz
Optional: false
QoS Class: Burstable
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s
node.kubernetes.io/unreachable:NoExecute for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled <unknown> default-scheduler Successfully assigned default/newjenkins-84cd855fb6-mr9rm to worker-node2
Normal Pulling 9m41s kubelet, worker-node2 Pulling image "jenkins/jenkins:lts"
[root#kube-master tmp]# kubectl describe pod newjenkins-84cd855fb6-mr9rm
Name: newjenkins-84cd855fb6-mr9rm
Namespace: default
Priority: 0
Node: worker-node2/192.168.20.56
Start Time: Thu, 14 May 2020 14:58:13 +0500
Labels: app.kubernetes.io/component=jenkins-master
app.kubernetes.io/instance=newjenkins
app.kubernetes.io/managed-by=Tiller
app.kubernetes.io/name=jenkins
helm.sh/chart=jenkins-1.16.0
pod-template-hash=84cd855fb6
Annotations: checksum/config: 70d4b49bc5cd79a1a978e1bbafdb8126f8accc44871772348fd481642e33cffb
Status: Pending
IP:
IPs: <none>
Controlled By: ReplicaSet/newjenkins-84cd855fb6
Init Containers:
copy-default-config:
Container ID:
Image: jenkins/jenkins:lts
Image ID:
Port: <none>
Host Port: <none>
Command:
sh
/var/jenkins_config/apply_config.sh
State: Waiting
Reason: ErrImagePull
Ready: False
Restart Count: 0
Limits:
cpu: 2
memory: 4Gi
Requests:
cpu: 50m
memory: 256Mi
Environment:
ADMIN_PASSWORD: <set to the key 'jenkins-admin-password' in secret 'newjenkins'> Optional: false
ADMIN_USER: <set to the key 'jenkins-admin-user' in secret 'newjenkins'> Optional: false
Mounts:
/tmp from tmp (rw)
/usr/share/jenkins/ref/secrets/ from secrets-dir (rw)
/var/jenkins_config from jenkins-config (rw)
/var/jenkins_home from jenkins-home (rw)
/var/jenkins_plugins from plugin-dir (rw)
/var/run/secrets/kubernetes.io/serviceaccount from newjenkins-token-jmfsz (ro)
Containers:
jenkins:
Container ID:
Image: jenkins/jenkins:lts
Image ID:
Ports: 8080/TCP, 50000/TCP
Host Ports: 0/TCP, 0/TCP
Args:
--argumentsRealm.passwd.$(ADMIN_USER)=$(ADMIN_PASSWORD)
--argumentsRealm.roles.$(ADMIN_USER)=admin
--httpPort=8080
State: Waiting
Reason: PodInitializing
Ready: False
Restart Count: 0
Limits:
cpu: 2
memory: 4Gi
Requests:
cpu: 50m
memory: 256Mi
Liveness: http-get http://:http/login delay=90s timeout=5s period=10s #success=1 #failure=5
Readiness: http-get http://:http/login delay=60s timeout=5s period=10s #success=1 #failure=3
Environment:
POD_NAME: newjenkins-84cd855fb6-mr9rm (v1:metadata.name)
JAVA_OPTS:
JENKINS_OPTS:
JENKINS_SLAVE_AGENT_PORT: 50000
ADMIN_PASSWORD: <set to the key 'jenkins-admin-password' in secret 'newjenkins'> Optional: false
ADMIN_USER: <set to the key 'jenkins-admin-user' in secret 'newjenkins'> Optional: false
Mounts:
/tmp from tmp (rw)
/usr/share/jenkins/ref/plugins/ from plugin-dir (rw)
/usr/share/jenkins/ref/secrets/ from secrets-dir (rw)
/var/jenkins_config from jenkins-config (ro)
/var/jenkins_home from jenkins-home (rw)
/var/run/secrets/kubernetes.io/serviceaccount from newjenkins-token-jmfsz (ro)
Conditions:
Type Status
Initialized False
Ready False
ContainersReady False
PodScheduled True
Volumes:
plugins:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit: <unset>
tmp:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit: <unset>
jenkins-config:
Type: ConfigMap (a volume populated by a ConfigMap)
Name: newjenkins
Optional: false
secrets-dir:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit: <unset>
plugin-dir:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
SizeLimit: <unset>
jenkins-home:
Type: PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace)
ClaimName: newjenkins
ReadOnly: false
newjenkins-token-jmfsz:
Type: Secret (a volume populated by a Secret)
SecretName: newjenkins-token-jmfsz
Optional: false
QoS Class: Burstable
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s
node.kubernetes.io/unreachable:NoExecute for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled <unknown> default-scheduler Successfully assigned default/newjenkins-84cd855fb6-mr9rm to worker-node2
Warning Failed 50s kubelet, worker-node2 Failed to pull image "jenkins/jenkins:lts": rpc error: code = Unknown desc = unauthorized: authentication required
Warning Failed 50s kubelet, worker-node2 Error: ErrImagePull
Normal SandboxChanged 49s kubelet, worker-node2 Pod sandbox changed, it will be killed and re-created.
Normal Pulling 28s (x2 over 10m) kubelet, worker-node2 Pulling image "jenkins/jenkins:lts"
Pull the jenkins image manually using docker pull jenkins with docker hub login and without docker hub account login, every time Give me error ErrImagePull.

Answer 1

The hint is in the Events section:
Failed to pull image "jenkins/jenkins:lts": rpc error: code = Unknown desc = unauthorized: authentication required
The kubelet on worker nodes performs a docker pull prior to executing the pod when it spins up the containers.
Make sure the node is logged in with docker login so the local worker nodes can pull the image manually, if you haven't already.
If you have and it's still happening, you may need a secret in place to access the repository in question. If it's still happening even then, don't use a short name for your image (not jenkins/jenkins:lts, specify the full path, like my-image-registry:5001/jenkins/jenkins:lts) to ensure it's pulling from the right place and not the default registries Docker is configured with. Hope that helps.