This is what I keep getting:
[root@centos-master ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
nfs-server-h6nw8 1/1 Running 0 1h
nfs-web-07rxz 0/1 CrashLoopBackOff 8 16m
nfs-web-fdr9h 0/1 CrashLoopBackOff 8 16m
Below is output from describe pods
kubectl describe pods
Events:
FirstSeen LastSeen Count From SubobjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
16m 16m 1 {default-scheduler } Normal Scheduled Successfully assigned nfs-web-fdr9h to centos-minion-2
16m 16m 1 {kubelet centos-minion-2} spec.containers{web} Normal Created Created container with docker id 495fcbb06836
16m 16m 1 {kubelet centos-minion-2} spec.containers{web} Normal Started Started container with docker id 495fcbb06836
16m 16m 1 {kubelet centos-minion-2} spec.containers{web} Normal Started Started container with docker id d56f34ae4e8f
16m 16m 1 {kubelet centos-minion-2} spec.containers{web} Normal Created Created container with docker id d56f34ae4e8f
16m 16m 2 {kubelet centos-minion-2} Warning FailedSync Error syncing pod, skipping: failed to "StartContainer" for "web" with CrashLoopBackOff: "Back-off 10s restarting failed container=web pod=nfs-web-fdr9h_default(461c937d-d870-11e6-98de-005056040cc2)"
I have two pods: nfs-web-07rxz, nfs-web-fdr9h, but if I do kubectl logs nfs-web-07rxz or with -p option I don't see any log in both pods.
[root@centos-master ~]# kubectl logs nfs-web-07rxz -p
[root@centos-master ~]# kubectl logs nfs-web-07rxz
This is my replicationController yaml file: replicationController yaml file
apiVersion: v1 kind: ReplicationController metadata: name: nfs-web spec: replicas: 2 selector:
role: web-frontend template:
metadata:
labels:
role: web-frontend
spec:
containers:
- name: web
image: eso-cmbu-docker.artifactory.eng.vmware.com/demo-container:demo-version3.0
ports:
- name: web
containerPort: 80
securityContext:
privileged: true
My Docker image was made from this simple docker file:
FROM ubuntu
RUN apt-get update
RUN apt-get install -y nginx
RUN apt-get install -y nfs-common
I am running my kubernetes cluster on CentOs-1611, kube version:
[root@centos-master ~]# kubectl version
Client Version: version.Info{Major:"1", Minor:"3", GitVersion:"v1.3.0", GitCommit:"86dc49aa137175378ac7fba7751c3d3e7f18e5fc", GitTreeState:"clean", BuildDate:"2016-12-15T16:57:18Z", GoVersion:"go1.6.3", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"3", GitVersion:"v1.3.0", GitCommit:"86dc49aa137175378ac7fba7751c3d3e7f18e5fc", GitTreeState:"clean", BuildDate:"2016-12-15T16:57:18Z", GoVersion:"go1.6.3", Compiler:"gc", Platform:"linux/amd64"}
If I run the docker image by docker run I was able to run the image without any issue, only through kubernetes I got the crash.
Can someone help me out, how can I debug without seeing any log?
As @Sukumar commented, you need to have your Dockerfile have a Command to run or have your ReplicationController specify a command.
The pod is crashing because it starts up then immediately exits, thus Kubernetes restarts and the cycle continues.