Error in the Lab 10.1: "error: unable to upgrade connection: container not found ("ngix")"

zhangwe

When I did the step 11, I found the pod "thirdpage-77c4bc9757-bwbpx" not running. And then I finished step 12 and 13. When I tried to do step 14 , I got an error "error: unable to upgrade connection: container not found ("ngix")". Could you please help me to figure out this?

Thanks,

Wei

student@master:~$ kubectl create deployment thirdpage --image=ngix
deployment.apps/thirdpage created
student@master:~$ kubectl get po
NAME READY STATUS RESTARTS AGE
secondapp-5cf87c9f48-cxtj2 1/1 Running 0 20h
thirdpage-77c4bc9757-bwbpx 0/1 ImagePullBackOff 0 14s

student@master:~$ kubectl expose deployment thirdpage --type=NodePort --port=80
service/thirdpage exposed
student@master:~$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 443/TCP 5d4h
secondapp NodePort 10.98.205.187 80:32497/TCP 20h
thirdpage NodePort 10.102.251.101 80:32023/TCP 4s

student@master:~$ kubectl exec -it thirdpage-77c4bc9757-bwbpx -- /bin/bash
error: unable to upgrade connection: container not found ("ngix")

chrispokorni

Hi Wei,

I am not sure there is such an image ngix available in the Docker Hub registry, so it makes sense that there is no such pod in your Kubernetes cluster either.
Try double-checking the spelling of the image name. This is just the result of a simple typo in your command.

Regards,
-Chris

zhangwe

Yes, my image name is not right. Thank you very much for your help.

krunallathiya

The error message "error: unable to upgrade connection: container not found ("ngix")" that you are encountering in Kubernetes typically indicates that there's an issue with the container name specified in your command. It seems like there might be a typo in the container name.

In Kubernetes, when you execute a command like kubectl exec to enter a container, you need to specify the exact name of the container if the pod has multiple containers. The error suggests that Kubernetes cannot find a container named "ngix" in the specified pod. This name seems like it's intended to be "nginx", the name of a popular web server.

Here’s how you can troubleshoot and potentially resolve this issue:

1. Check the Pod's Container Names
   First, verify the name of the container inside the pod. You can list all containers in a pod using the following command:

kubectl get pod thirdpage-77c4bc9757-bwbpx -o jsonpath='{.spec.containers[*].name}'

2. Correct the Container Name
   Use the correct container name in your kubectl exec command. If the container is indeed named "nginx", the command should look something like this:

kubectl exec -it thirdpage-77c4bc9757-bwbpx -c nginx -- /bin/bash

3. Check the Pod Status

Since you mentioned the pod "thirdpage-77c4bc9757-bwbpx" was not running, ensure that the pod is in a running state. You can check the status of the pod with:

kubectl get pod thirdpage-77c4bc9757-bwbpx