K8s pod ImagePullBackoff - kubernetes

Question

created a very simple nginx pod and run into status ImagePullBackoff
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 32m default-scheduler Successfully assigned reloader/nginx to aks-appnodepool1-22779252-vmss000000
Warning Failed 29m kubelet Failed to pull image "nginx": rpc error: code = Unknown desc = failed to pull and unpack image "docker.io/library/nginx:latest": failed to resolve reference "docker.io/library/nginx:latest": failed to do request: Head "https://registry-1.docker.io/v2/library/nginx/manifests/latest": dial tcp 52.200.78.26:443: i/o timeout
Warning Failed 27m kubelet Failed to pull image "nginx": rpc error: code = Unknown desc = failed to pull and unpack image "docker.io/library/nginx:latest": failed to resolve reference "docker.io/library/nginx:latest": failed to do request: Head "https://registry-1.docker.io/v2/library/nginx/manifests/latest": dial tcp 52.21.28.242:443: i/o timeout
Warning Failed 23m kubelet Failed to pull image "nginx": rpc error: code = Unknown desc = failed to pull and unpack image "docker.io/library/nginx:latest": failed to resolve reference "docker.io/library/nginx:latest": failed to do request: Head "https://registry-1.docker.io/v2/library/nginx/manifests/latest": dial tcp 3.223.210.206:443: i/o timeout
Normal Pulling 22m (x4 over 32m) kubelet Pulling image "nginx"
Warning Failed 20m (x4 over 29m) kubelet Error: ErrImagePull
Warning Failed 20m kubelet Failed to pull image "nginx": rpc error: code = Unknown desc = failed to pull and unpack image "docker.io/library/nginx:latest": failed to resolve reference "docker.io/library/nginx:latest": failed to do request: Head "https://registry-1.docker.io/v2/library/nginx/manifests/latest": dial tcp 3.228.155.36:443: i/o timeout
Warning Failed 20m (x7 over 29m) kubelet Error: ImagePullBackOff
Warning Failed 6m41s kubelet Failed to pull image "nginx": rpc error: code = Unknown desc = failed to pull and unpack image "docker.io/library/nginx:latest": failed to resolve reference "docker.io/library/nginx:latest": failed to do request: Head "https://registry-1.docker.io/v2/library/nginx/manifests/latest": dial tcp 52.5.157.114:443: i/o timeout
Normal BackOff 2m17s (x65 over 29m) kubelet Back-off pulling image "nginx"
Checked network status:
A VM in the same subnet can access "https://registry-1.docker.io/v2/library/nginx/manifests/latest" and telnet 52.5.157.114 443 successful.
docker pull nginx successfully on the VM in the same subnet.
kubectl exec into a running pod in the same cluster can wget https://registry-1.docker.io/v2/library/nginx/manifests/latest successfully.
.
What is the possible problem?

Answer 1

When I wget/curl or anything you want to access
https://registry-1.docker.io/v2/library/nginx/manifests/latest
It says
{"errors":[{"code":"UNAUTHORIZED","message":"authentication required","detail":[{"Type":"repository","Class":"","Name":"library/nginx","Action":"pull"}]}]}
However this is because you need to be logged in to pull this image from this repository.
2 solutions:
The first is simple, in the image field just replace this url by nginx:latest and it should work
The second: create a regcred

Answer 2

in your pod yaml , change image : docker.io/library/nginx:latest to docker.io/nginx:latest

Answer 3

Turned out to be firewall dropped the package.