I have a VM with kubernetes installed using kubeadm (NOT minikube). The VM acts a the single node of the cluster, with taints removed to allow it to act as both Master and Worker node (as shown in the kubernetes documentation). I have saved, transfered and loaded a my app:test image into it. I can easily run a container with it using docker run. It shows up when I run sudo docker images.
When I create a deployment/pod that uses this image and specify Image-PullPolicy: IfNotPresent or Never, I still have the ImagePullBackoff error. The describe command shows me it tries to pull the image from dockerhub...
Note that when I try to use a local image that was pulled as the result of creating another pod, the ImagePullPolicies seem to work, no problem. Although the image doesn't appear when i run sudo docker images --all.
How can I use a local image for pods in kubernetes? Is there a way to do it without using a private repository?
TLDR: these steps, which are also described in the crictl github documentation:
1- Once you get the image on the node (in my case, a VM), make sure it is in an archive (.tar). You can do that with the docker save or ctr image export commands.
2- Use sudo ctr -n=k8s.io images import myimage.tar while in the same directory as thearchived image to add it to containerd in the namespace that kubernetes uses to track it's images. It should now appear when you run sudo crictl images.
As suggested, I tried listing images with crictl and my app:test did not appear. However, trying to import my local image through crictl didn't seem to work either. I used crictl pull app:test and it showed the following error message:
FATA[0000] pulling image failed: rpc error: code = Unknown desc = failed to pull and unpack image "docker.io/library/app:test": failed to resolve reference "docker.io/library/app:test": pull access denied, repository does not exist or may require authorization: server message: insufficient_scope: authorization failed.
However, when following these steps, my image is finally recognized as an existing local image in kubernetes. They are actually the same as suggested in the crictl github documentation
How does one explain this? How do images get "registered" in the kubernetes cluster? Why couldn't crictl import the image? I might post another issue to ask that...