Container checkpointing on Minikube with CRIO

Question

We are trying to take a snapshot of a container with the Kubernetes Container checkpointing feature.

Environment: minikube

runtime-contaner: crio

We tried the following:

1. Start a new profile in minikube setting the ContainerCheckpoint feature flag:

   minikube start --container-runtime=crio --feature-gates=ContainerCheckpoint=true -p criupoc

2. Review configuration to make sure that the feature gate is setup correctly:

   vim ~/.minikube/profiles/criupoc/config.json

3. Created nginx pod and verify that it's running:

   kubectl apply -f https://k8s.io/examples/pods/simple-pod.yaml kubectl get pods

4. Try the checkpointing feature as advised in the documentation (already linked above):

   curl --insecure --cert ~/.minikube/profiles/criupoc/client.crt --key ~/.minikube/profiles/criupoc/client.key -X POST "https://<MINIKUBEIP_PLACEHOLDER>:10250/checkpoint/default/nginx/nginx"

Expected: checkpoint is taken

Actual: checkpointing of default/nginx/nginx failed (rpc error: code = Unimplemented desc = unknown method CheckpointContainer for service runtime.v1.RuntimeService)

Notes:

• I tried this with the docker container-runtime (in minikube) too, with the same results. As per containerd, it seems like it doesn't support CRIU yet.
• This example, suggests to use also the flag --enable-criu-support=true within cri-o but I have no idea how to set it through minikube or in any other ways.

QUESTION: Could you please provide some insight into this? How could I fix this error or alter my procedure to get a snapshot of the nginx container?

Answer 1

As it seems that the feature is newly launched, I was only able to gather documentation using containerd. Linking here the documentation where the steps provided on taking a snapshot of container image with checkpoint in containerd.

Attaching here as well a reference documentation about CRIU that you can connect yourself for further updates.