Implement CRI Debug API

[Random-Liu]

We added the verbose option in CRI to make it possible for container runtime to provide more information for debug. kubernetes/kubernetes#53965

We should implement it in cri-containerd.

Functions we need to change:

• ContainerStatus
• PodSandboxStatus
• ImageStatus
• Status

We need to:

1. Take a look at what information is included in today's docker inspect and docker info, and properly design what debug information we should include in cri-containerd.
2. Add those information in corresponding functions.
3. Change crictl to consume the extra information.

[mikebrow]

Background issue:
kubernetes/kubernetes#53757

[weiwei04]

If there's no one doing this, I can take a try :)

[mikebrow]

I've started it, but not far along.

[Random-Liu]

@weiwei04 There will be various issues filed by @mikebrow or me for this in both cri-containerd and cri-tools repositories.

Feel free to pick one if you are interested. :)

[Random-Liu]

Things might be useful for container info:

• container config.
• pid.
• more

[abhi]

Starting on this

[mikebrow]

hey ok been busy :-)

[mikebrow]

"value should be in json format" grr

[mikebrow]

ok added:

Container Status:

• container config.
• pid.
• removing state.
• container runtime spec.
• snapshotter info.

[mikebrow]

See kubernetes-sigs/cri-tools#206

[Random-Liu]

Add sandbox id in container status. We should add it into CRI eventually, but it's code freeze now.

[mikebrow]

A little back link to the pod.. ok I like it. Done (added sandbox id) see updated #452

[mikebrow]

Added:
Container Status:

• sandboxID

Pod Status:

• pid
• state
• runtimeSpec
• snapshotter info

[mikebrow]

Added:

Image Status:

• chainID
• imagespec(image structure from OCI)

[mikebrow]

** ok now that we've got a decent amount of debug info in the verbose mode, we need to go back and add (or consider adding) some group structs for the verbose information. This is because the order for the data in the map is random and might not make as much sense out of order as it would in some defined sequence at least for a group of items.

Eg. "snapshotInfo": { "snapshotKey": ... "snapshotter":... }

[mikebrow]

Pod and Image verbose info are ready for final review.

[mikebrow]

Image verbose is ready for final review...

[Random-Liu]

@mikebrow All done. I think we can close this one.

Can you add a simple document for crictl? For #96

We just need a reference somewhere in our repo.
It should point out that:

1. We should use crictl for debugging cri-containerd.
2. A simple example, e.g. crictl inspect.
3. Link to crictl document.