[Mega Tracking] Align Prysm to Interop Networking Spec

[prestonvanloon]

The new interop networking spec has been merged (ethereum/consensus-specs#1328).

Spec requirements

Interop requirements:

• Support libp2p TCP transport for inbound/outbound IPv4 and IPv6 addresses.
• Expose at least one IPv4 endpoint. Implement Discv5 in Prysm #3211
• All endpoints must be publicly dialable (no advertising local networked addresses or relay)
• Testnet infrastructure configured to enable direct, inbound traffic
• SecIO w/ secp256k1 for identity
• mplex protocol for multiplexing
• (optional) yamux protocol for multiplexing
• Gossipsub alignment
• RPC (req/res) alignment
• Discovery (discv5) alignment

Mainnet requirements:

• Noise handshakes (Moved to Implement Noise Framework Handshakes for Mainnet #3687)

Code changes

Not in any particular order. See networking design doc.

Migration:

• Move/prefix sync and p2p packages with deprecated- as part of the migration. Move sync to deprecated- prefix #3190 Move p2p to deprecated-p2p #3191
• Mark existing p2p pb messages as deprecated Mark deprecated protobuf p2p msgs #3194
• Mark existing topic mappings as deprecated Deprecate node p2p config #3192 Mark deprecated protobuf p2p msgs #3194

p2p package:

• Add new p2p package with boilerplate libp2p configuration New p2p package  #3196
• Add unit tests and explicit config to ensure libp2p configuration parameters meet the network spec requirements Add gossipsub parameter test #3200

p2p encoding:

• Add API for encoding registration
• Register ssz encoder/decoder ssz network encoder (with snappy compression) #3198 Add varint prefixing to ssz network encoder #3210
• Register ssz_snappy encoder/decoder ssz network encoder (with snappy compression) #3198 Add varint prefixing to ssz network encoder #3210
• Add encoding enum flag for selecting the p2p encoding Add Flag for SSZ Encoding #3256
• Prefix ssz encoded data with protobuf.Varint length indicator Add varint prefixing to ssz network encoder #3210

p2p hello/goodbye:

• Add peerstore abstraction for tracking handshake responses
• Add handler for hello sync RPC: Hello handler #3216
• Add handler for goodbye Implement GoodBye RPC Handler #3282

Initial sync:

• Add round robin sync strategy
• Add logic to sync round robin up to finalized epoch
• Add logic to sync to head after finalized epoch

Topic mappings:

• Add new message topic mappings Regular Sync - First Pass #3201

Regular sync RPC:

• /eth2/beacon_chain/req/beacon_blocks/1/{ssz,ssz_snappy} handler Reg sync beacon blocks #3218
• /eth2/beacon_chain/req/recent_beacon_blocks/1/{ssz,ssz_snappy} handler Add Recent Blocks RPC Request Handler #3281
• /eth2/beacon_chain/req/hello/1/{ssz,ssz_snappy} handler sync RPC: Hello handler #3216
• /eth2/beacon_chain/req/goodbye/1/{ssz,ssz_snappy} handler Implement GoodBye RPC Handler #3282
• Add new message types Add new p2p messages for RPC #3199

Regular sync gossip sub:

• /eth2/beacon_block/{ssz,ssz_snappy} handler & validator Regular sync: pubsub subscriber for beacon blocks #3220
• /eth2/beacon_attestation/{ssz,ssz_snappy} handler & validator
• /eth2/voluntary_exit/{ssz,ssz_snappy} handler & validator Regular sync: pubsub subscriber for voluntary exits #3227
• /eth2/proposer_slashing/{ssz,ssz_snappy} handler & validator
• /eth2/attester_slashing/{ssz,ssz_snappy} handler & validator

Broadcaster:

• Broadcast with encoding Add p2p broadcast implementation #3226

Fork choice:

• Add ReceiveBlock path that does not apply fork choice (for initial sync up to finalized epoch)

Discovery:

• Change bootnode to use Discv5 instead of kademlia Change BootNode to use Discv5 instead of Kademlia #3203
• Allow node discovery via Discv5. Implement Discv5 in Prysm #3211
  - [ ] Handle topic search for stored node records.
  - [ ] Standardize interfaces to match libp2p for discovery and peer routing
• ENR for nodes in prysm must conform with the required fields as stated here

Ssz:

• Add support for proto enum fields (int32) Support int32 fields go-ssz#66

[terencechain]

Interested in gossips and rpc alignments

[nisdas]

interested in discovery and RPC alingment