kubernetes giving CrashLoopBackOff error while creating pods - linux

Question

I'm creating a pod of node container, and it is giving CrashLoopBackOff error.
kubectl get pods
kubectl describe pod test-node3
Any help would be appreciated.

Answer 1

You can add command as below so that pod will remain in running state.
apiVersion: v1
kind: Pod
metadata:
name: myapp-pod
labels:
app: myapp
spec:
containers:
- name: myapp-container
image: busybox
command: ['sh', '-c', 'echo Hello Kubernetes! && sleep 3600']
Ref: Doc

Answer 2

Your container does not have a long running process. The main process in the container is exiting with exit code 0 which usually means that the process has terminated successfully. You can see it in the kubectl describe output you have shared.
Reason: Completed
Exit Code: 0

Answer 3

Once Pod is assigned to a node by scheduler, kubelet starts creating containers using container runtime. There are three possible states of containers: Waiting, Running and Terminated.
Terminated: Indicates that the container completed its execution and has stopped running.
A container enters into this when it has successfully completed execution or when it has failed for some reason. Regardless, a reason and exit code is displayed, as well as the container’s start and finish time.
On your screenshot its clear that container inside pod is running to completion with its work done, with exit code 0 as below snippet
State: Terminated
Reason: Completed
Exit Code: 0
You should either add a long running process to your container or define restartPolicy: Never on pod definition.
Tested your image with adding correct restart policy and POD runs correctly to completion with no crash
kubectl run test --image=abhishekk27/kube-pub:new --restart=Never
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
test 0/1 Completed 0 8m12s
yaml genrated :
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
labels:
run: test
name: test
spec:
containers:
- image: abhishekk27/kube-pub:new
name: test
resources: {}
dnsPolicy: ClusterFirst
restartPolicy: Never
Result:
$ kubectl describe pod test
Name: test
Namespace: default
Priority: 0
Node: dlv-k8s-node-1/131.160.200.104
Start Time: Fri, 17 Jan 2020 09:45:00 +0000
Labels: run=test
Annotations: <none>
Status: Succeeded
IP: 10.244.1.12
IPs:
IP: 10.244.1.12
Containers:
test:
Container ID: docker://b335e5fef022dced824f85ba2bfe4c024608c9b5463599eb36591a14d709786d
Image: abhishekk27/kube-pub:new
Image ID: docker-pullable://abhishekk27/kube-pub#sha256:6a696bd733edaa48b9be781960f4ee178d16f1c9aea51e53bd0f54326a3d05b1
Port: <none>
Host Port: <none>
State: Terminated
Reason: Completed
Exit Code: 0
Started: Fri, 17 Jan 2020 09:45:48 +0000
Finished: Fri, 17 Jan 2020 09:45:48 +0000
Ready: False
Restart Count: 0
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-7f4mt (ro)
Conditions:
Type Status
Initialized True
Ready False
ContainersReady False
PodScheduled True
Volumes:
default-token-7f4mt:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-7f4mt
Optional: false
QoS Class: BestEffort
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 6m50s default-scheduler Successfully assigned default/test to dlv-k8s-node-1
Normal Pulling 6m46s kubelet, dlv-k8s-node-1 Pulling image "abhishekk27/kube-pub:new"
Normal Pulled 5m58s kubelet, dlv-k8s-node-1 Successfully pulled image "abhishekk27/kube-pub:new"
Normal Created 5m58s kubelet, dlv-k8s-node-1 Created container test
Normal Started 5m58s kubelet, dlv-k8s-node-1 Started container test