GC Improvement

[s1061123]

Currently GC calls with cni.dev/valid-attachments arguments, to specify current valid attachments based on network config.

https://github.com/containernetworking/cni/blob/c04330ee9e0bb932e1e3eda757813e2f212e746b/libcni/api.go#L113

If there is multiple network config (one or more CNI is configured in container runtime or by multus), then one plugin may receives multiple GC calls for each network config. (e.g. pluginA GC for config1 and pluignA GC for config2). GC takes a bit huge computation cost, so we should optimize it as much as we can.

Hence we could improve GC calls by

• Add new GC API (or we just change current GC API because currently none uses it yet)

 GCNetworkLists(ctx context.Context, net []*NetworkConfigList, args *GCArgs) error

• In new API, we optimize (sort and dedup) for each plugin, invoke GC with valid arguments.

[maiqueb]

/cc