[feature request] CRI pause/unpause container interface

[zhuangqh]

Why you need it?

Under serverless situation, we may pre-allocate a batch of container which were ready to serve, waiting online. In order to reduce the cost of system resource, we stop these containers, and start them when they are required to serve.

I propose using pause container to balance the resource cost and application start-up time.

How it could be?

extend the CRI v1alpha2 interface, allow to pause/unpause a container through CRI.

service RuntimeService {
...
    // PauseContainer pauses the container.
    rpc PauseContainer(PauseContainerRequest) returns (PauseContainerResponse) {}
    // UnpauseContainer unpauses the container.
    rpc UnpauseContainer(UnpauseContainerRequest) returns (UnpauseContainerResponse) {}
...
}

message PauseContainerRequest {
    // ID of the container to pause.
    string container_id = 1;
}

message PauseContainerResponse {}

message UnpauseContainerRequest {
    // ID of the container to unpause.
    string container_id = 1;
}

message UnpauseContainerResponse {}

Other related information

CRI client interface (generated by protoc)

type RuntimeServiceClient interface {
...
	// PauseContainer pauses a container
	PauseContainer(ctx context.Context, in *PauseContainerRequest, opts ...grpc.CallOption) (*PauseContainerResponse, error)
	// UnpauseContainer unpauses a container to running
	UnpauseContainer(ctx context.Context, in *UnpauseContainerRequest, opts ...grpc.CallOption) (*UnpauseContainerResponse, error)
...
}

[zhuangqh]

TODO

• CRI interface implement
• CRI test cover

[zhuangqh]

test: alibaba-archive/cri-tools#11