This commit adds PeerAdd() and PeerRemove() endpoints, CLI support,
tests. Peer management is a delicate issue because of how the consensus
works underneath and the places that need to track such peers.
When adding a peer the procedure is as follows:
* Try to open a connection to the new peer and abort if not reachable
* Broadcast a PeerManagerAddPeer operation which tells all cluster members
to add the new Peer. The Raft leader will add it to Raft's peerset and
the multiaddress will be saved in the ClusterPeers configuration key.
* If the above fails because some cluster node is not responding,
broadcast a PeerRemove() and try to undo any damage.
* If the broadcast succeeds, send our ClusterPeers to the new Peer along with
the local multiaddress we are using in the connection opened in the
first step (that is the multiaddress through which the other peer can reach us)
* The new peer updates its configuration with the new list and joins
the consensus
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
The former RPC stuff had become a monster, really hard to have an overview
of the RPC api capabilities and with lots of magic.
go-libp2p-rpc allows to have a clearly defined RPC api which
shows which methods every component can use. A component to perform
remote requests, and the convoluted LeaderRPC, BroadcastRPC methods are
no longer necessary.
Things are much simpler now, less goroutines are needed, the central channel
handling bottleneck is gone, RPC requests are very streamlined in form.
In the future, it would be inmediate to have components living on different
libp2p hosts and it is way clearer how to plug into the advanced cluster rpc
api.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>