kubectl get pods shows CrashLoopBackoff

Question

Im trying to create a pod using my local docker image as follow.

1.First I run this command in terminal

eval $(minikube docker-env)

2.I created a docker image as follow

sudo docker image build -t my-first-image:3.0.0 .

3.I created the pod.yml as shown below and I run this command

kubectl -f create pod.yml.

4.then i tried to run this command

kubectl get pods

but it shows following error


NAME                                  READY   STATUS             RESTARTS   AGE
multiplication-6b6d99554-d62kk        0/1     CrashLoopBackOff   9          22m
multiplication2019-5b4555bcf4-nsgkm   0/1     CrashLoopBackOff   8          17m
my-first-pod                          0/1     CrashLoopBackOff   4          2m51

5.i get the pods logs

kubectl describe pod my-first-pod


Events:
  Type     Reason     Age                    From               Message
  ----     ------     ----                   ----               -------
  Normal   Scheduled  6m22s                  default-scheduler  Successfully assigned default/my-first-pod to minikube
  Normal   Pulled     5m20s (x4 over 6m17s)  kubelet, minikube  Successfully pulled image "docker77nira/myfirstimage:latest"
  Normal   Created    5m20s (x4 over 6m17s)  kubelet, minikube  Created container
  Normal   Started    5m20s (x4 over 6m17s)  kubelet, minikube  Started container
  Normal   Pulling    4m39s (x5 over 6m21s)  kubelet, minikube  pulling image "docker77nira/myfirstimage:latest"
  Warning  BackOff    71s (x26 over 6m12s)   kubelet, minikube  Back-off restarting failed container

Dockerfile

    FROM node:carbon
    WORKDIR /app
    COPY . .
    CMD [ "node", "index.js" ]

pods.yml

    kind: Pod
    apiVersion: v1
    metadata:
     name: my-first-pod
    spec:
     containers:
     - name: my-first-container
       image: my-first-image:3.0.0

index.js

    var http = require('http');
    var server = http.createServer(function(request, response) {
     response.statusCode = 200;
     response.setHeader('Content-Type', 'text/plain');
     response.end('Welcome to the Golden Guide to Kubernetes
    Application Development!');
    });
    server.listen(3000, function() {
     console.log('Server running on port 3000');
    });

score 2 · Answer 1 · answered Mar 28 '19 at 09:14

2

Try checking logs with command kubectl logs -f my-first-pod

answered Mar 28 '19 at 09:14

Akash Sharma

721
3
6

To elaborate, `CrashLoopBackOff` means that your service is crashing every time the container is created, so you need to find out what is going wrong with your service on startup. – kristaps Mar 28 '19 at 09:22

score 1 · Answer 2 · answered Mar 28 '19 at 09:33

kind: Pod
    apiVersion: v1
    metadata:
     name: my-first-pod
    spec:
     containers:
     - name: my-first-container
       image: my-first-image:3.0.0
       command: [ "sleep" ]
       args: [ "infinity" ]

I think your pod is getting terminated after execution of script inside index.js

score 1 · Accepted Answer · edited Apr 02 '19 at 14:02

I succeeded in running your image by performing these steps:

docker build -t foo .

then check if the container is working docker run -it foo

/app/index.js:5
response.end('Welcome to the Golden Guide to Kubernetes
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

SyntaxError: Invalid or unexpected token
    at createScript (vm.js:80:10)
    at Object.runInThisContext (vm.js:139:10)
    at Module._compile (module.js:617:28)
    at Object.Module._extensions..js (module.js:664:10)
    at Module.load (module.js:566:32)
    at tryModuleLoad (module.js:506:12)
    at Function.Module._load (module.js:498:3)
    at Function.Module.runMain (module.js:694:10)
    at startup (bootstrap_node.js:204:16)
    at bootstrap_node.js:625:3

Not sure if this was the outcome you wanted to see, the container itself runs. But in Kubernetes it gets into ErrImagePull

Then after editing your Pod.yaml inspired by @Harsh Manvar it works fine with this. So the problem with exiting after completed command was just part of the problem.

apiVersion: v1
kind: Pod
metadata:
  name: hello-pod
spec:
  restartPolicy: Never
  containers:
  - name: hello
    image: "foo"
    imagePullPolicy: Never
    command: [ "sleep" ]
    args: [ "infinity" ]

This is Minikube so you can reuse the images, but if you would have more nodes this might not work at all. You can find a good explanation about using local docker images with Kubernetes here.

kubectl get pods shows CrashLoopBackoff

3 Answers3