Kind: Can't preload images on a cluster with the :latest tag

[aojea]

What happened:

Trying to preload images in a cluster with the :latest tag doesn't work, kubelet never use the local image and always try to fetch it from the registry,.

What you expected to happen:

Being able to preload images with the :latest tag in my clusters

How to reproduce it (as minimally and precisely as possible):

Build an image locally with the latest tag
Load the image into the cluster with kind load docker-image
Create a pod with that image
If you don;t have the image into the registry the kubelet will fail to download it and is easier to debug.

Anything else we need to know?:

Seems that's containerd expected behaviour

containerd will not cache images with the latest tag so make sure you do not use ..

Environment:

• kind version: (use kind version):
• Kubernetes version: (use kubectl version):
• Docker version: (use docker info):
• OS (e.g. from /etc/os-release):

[tao12345666333]

ref: https://kind.sigs.k8s.io/docs/user/quick-start/#loading-an-image-into-your-cluster

Note: The Kubernetes default pull policy is IfNotPresent unless the image tag is :latest in which case the default policy is Always. IfNotPresent causes the Kubelet to skip pulling an image if it already exists.

[tao12345666333]

also see: https://github.com/kubernetes-sigs/kind/issues/328

[aojea]

I think that kind load docker-image should fail for images with latest tag

[tao12345666333]

We provide the kind tool, which also has the load image function. For images containing :latest , this behavior is controlled by Kubernetes.

If we let load image return an error when it encounters :latest tag, I don't think it is reasonable. You can add a suggestion or a hint, maybe a better user experience.

[aojea]

I think you are absolutely right
Closing

[BenTheElder]

[just noting my agreement on the outcome 😅]

warning about :latest behavior might be a good idea 👍 I can dig out some code I wrote to solve this sort of thing with another tool (note: :latest is a magical default, and parsing these correctly has some edge cases... 🙃)