Currently (early v1.7 cycle), some of the global maps used by multiple BPF programs are opened/created from cilium-agent in the function below:

But others (such as conntrack, or the global tail call map) are not.

Note that we must make sure that if any map is being created, its attributes must match the attributes defined in the C templates, otherwise when we load a program for an endpoint the first time, it will delete/recreate the map.

Tasks:

• Gather a list of globally shared maps that are not opened/created in the daemon (see pkg/maps/ and bpf/)
• Make sure that the map attributes are guaranteed to be in sync for those map types between the BPF C definitions and the Golang definitions
• Add OpenOrCreate() calls for all maps to initMaps() so we can be sure that the globally shared maps are guaranteed to be in place before the first BPF program load
  • Some maps, such as the tail call maps, are never used from the cilium-agent. These should be created, and pinned to the filesystem, then the fd closed.