We cannot do this for "subscribe" and "partition" this easily without
breakage so those are omitted.
Any protobuf message passed around via an Any construct will have the
fully qualified package name embedded in the protobuf as a string. Also
RPC method dispatch will include the package of the service during
serialization.
- We will be passing pbservice and pbpeering through an Any as part of
peer stream replication.
- We will be exposing two new gRPC services via pbpeering and
pbpeerstream.
Previously, public referred to gRPC services that are both exposed on
the dedicated gRPC port and have their definitions in the proto-public
directory (so were considered usable by 3rd parties). Whereas private
referred to services on the multiplexed server port that are only usable
by agents and other servers.
Now, we're splitting these definitions, such that external/internal
refers to the port and public/private refers to whether they can be used
by 3rd parties.
This is necessary because the peering replication API needs to be
exposed on the dedicated port, but is not (yet) suitable for use by 3rd
parties.
- Use some protobuf construction helper methods for brevity.
- Rename a local variable to avoid later shadowing.
- Rename the Nonce field to be more like xDS's naming.
- Be more explicit about which PeerID fields are empty.
If someone were to switch a peer-exported service from L4 to L7 there
would be a brief SAN validation hiccup as traffic shifted to the mesh
gateway for termination.
This PR sends the mesh gateway SpiffeID down all the time so the clients
always expect a switch.
For L4/tcp exported services the mesh gateways will not be terminating
TLS. A caller in one peer will be directly establishing TLS connections
to the ultimate exported service in the other peer.
The caller will be doing SAN validation using the replicated SpiffeID
values shipped from the exporting side. There are a class of discovery
chain edits that could be done on the exporting side that would cause
the introduction of a new SpiffeID value. In between the time of the
config entry update on the exporting side and the importing side getting
updated peer stream data requests to the exported service would fail due
to SAN validation errors.
This is unacceptable so instead prohibit the exporting peer from making
changes that would break peering in this way.
Sarah Alsmiller