container-snapshot

Container Snapshot Operator

Taking snapshots for Docker containers running in Kubernetes.

This is a rewritten of qiniu-ava/snapshot-operator, and is inspired by wulibin163/kubepush.

How it works

1. The operator starts a worker. To communicate to the docker daemon runs the target container, the worker is configured to run on the same node of the target container.
2. The worker behaves as running docker commit to take a snapshot (as a new docker image) for the target container, and
3. running docker push to push the snapshot image.

How to use it

1. preparation:

   1. create CRD:

       kubectl apply -f ./deploy/crds/atom.supremind.com_containersnapshots_crd.yaml
      

   2. deploy operator:

       kubectl apply -f ./deploy
      

2. use a ContainerSnapshot

   1. create a pod and make sure it is running:

       kubectl apply -f example/pod.yaml
      

   2. create an image push secret

      The easies way to do this is creating one based on existing Docker credentials, more options could be found in the same page.

   3. create a ContainerSnapshot CR:

       kubectl apply -f example/containersnapshot.yaml
      

      you may need to change the imagePushSecrets.name to your secret name, and the image to a repository you have write access to

3. check to see the worker pod starts and ends:

    kubectl get po -w
   

4. validate the generated snapshot image contains target container's read/write layer:

    docker run --rm my-snapshots/example-snapshot:v0.0.1 -- cat /dates
   

Road map

• set worker pod template when start the operator
• set worker pod template in containerSnapshot spec