kubernetes pods卡在容器创建

Question

I have a raspberry pi cluster (one master , 3 nodes)

My basic image is : raspbian stretch lite

I already set up a basic kubernetes setup where a master can see all his nodes (kubectl get nodes) and they're all running. I used a weave network plugin for the network communication

When everything is all setup i tried to run a nginx pod (first with some replica's but now just 1 pod) on my cluster as followed kubectl run my-nginx --image=nginx

But somehow the pod get stuck in the status "Container creating" , when i run docker images i can't see the nginx image being pulled. And normally an nginx image is not that large so it had to be pulled already by now (15 minutes). The kubectl describe pods give the error that the pod sandbox failed to create and kubernetes will rec-create it.

I searched everything about this issue and tried the solutions on stackoverflow (reboot to restart cluster, searched describe pods , new network plugin tried it with flannel) but i can't see what the actual problem is. I did the exact same thing in Virtual box (just ubuntu not ARM ) and everything worked.

First i thougt it was a permission issue because i run everything as a normal user , but in vm i did the same thing and nothing changed. Then i checked kubectl get pods --all-namespaces to verify that the pods for the weaver network and kube-dns are running and also nothing wrong over there .

Is this a firewall issue in Raspberry pi ? Is the weave network plugin not compatible (even the kubernetes website says it is) with arm devices ? I 'am guessing there is an api network problem and thats why i can't get my pod runnning on a node

[EDIT] Log files

kubectl describe podName

>     
>     Name:           my-nginx-9d5677d94-g44l6 Namespace:      default Node: kubenode1/10.1.88.22 Start Time:     Tue, 06 Mar 2018 08:24:13
> +0000 Labels:         pod-template-hash=581233850
>                     run=my-nginx Annotations:    <none> Status:         Pending IP: Controlled By:  ReplicaSet/my-nginx-9d5677d94 Containers: 
> my-nginx:
>         Container ID:
>         Image:          nginx
>         Image ID:
>         Port:           80/TCP
>         State:          Waiting
>           Reason:       ContainerCreating
>         Ready:          False
>         Restart Count:  0
>         Environment:    <none>
>         Mounts:
>           /var/run/secrets/kubernetes.io/serviceaccount from default-token-phdv5 (ro) Conditions:   Type           Status  
> Initialized    True   Ready          False   PodScheduled   True
> Volumes:   default-token-phdv5:
>         Type:        Secret (a volume populated by a Secret)
>         SecretName:  default-token-phdv5
>         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               5m    default-scheduler   Successfully assigned my-nginx-9d5677d94-g44l6 to kubenode1   Normal  
> SuccessfulMountVolume   5m    kubelet, kubenode1  MountVolume.SetUp
> succeeded for volume "default-token-phdv5"   Warning 
> FailedCreatePodSandBox  1m    kubelet, kubenode1  Failed create pod
> sandbox.   Normal   SandboxChanged          1m    kubelet, kubenode1 
> Pod sandbox changed, it will be killed and re-created.

kubectl logs podName

Error from server (BadRequest): container "my-nginx" in pod "my-nginx-9d5677d94-g44l6" is waiting to start: ContainerCreating

journalctl -u kubelet gives this error

Mar 12 13:42:45 kubeMaster kubelet[16379]: W0312 13:42:45.824314   16379 cni.go:171] Unable to update cni config: No networks found in /etc/cni/net.d
Mar 12 13:42:45 kubeMaster kubelet[16379]: E0312 13:42:45.824816   16379 kubelet.go:2104] Container runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized

The problem seems to be with my network plugin. In my /etc/systemd/system/kubelet.service.d/10.kubeadm.conf . the flags for the network plugins are present ? environment= kubelet_network_args --cni-bin-dir=/etc/cni/net.d --network-plugin=cni

Answer 1

Thank you all for responding to my question. I solved my problem now. For anyone who has come to my question in the future the solution was as followed.

I cloned my raspberry pi images because i wanted a basicConfig.img for when i needed to add a new node to my cluster of when one gets down.

Weave network (the plugin i used) got confused because on every node and master the os had the same machine-id. When i deleted the machine id and created a new one (and reboot the nodes) my error got fixed. The commands to do this was

sudo rm /etc/machine-id
sudo rm /var/lib/dbus/machine-id
sudo dbus-uuidgen --ensure=/etc/machine-id

Once again my patience was being tested. Because my kubernetes setup was normal and my raspberry pi os was normal. I founded this with the help of someone in the kubernetes community. This again shows us how important and great our IT community is. To the people of the future who will come to this question. I hope this solution will fix your error and will decrease the amount of time you will be searching after a stupid small thing.

Answer 2

You can see if it's network related by finding the node trying to pull the image:

kubectl describe pod <name> -n <namespace>

SSH to the node, and run docker pull nginx on it. If it's having issues pulling the image manually, then it might be network related.