Initialization of a PoS blockchain

[adrianbrink]

Step 1

Currently, RequestInitChain passes in the validator set from the tendermint/genesis.json file and ResponseInitChain is an empty struct.

message RequestInitChain {
  repeated Validator validators = 1 [(gogoproto.nullable)=false];
  bytes app_state_bytes = 2;
}

ResponseInitChain should return Validator, a set of validators to start Tendermint consensus with.

message ResponseInitChain {
  repeated Validator validators = 1 [(gogoproto.nullable)=false];
}

Step 2

Furthermore, the field validators in both should not be nullable. InitChain should be a pure function, that takes a validator set and returns a validator set. Of course the RequestInitChain.validators field can be an empty array.

message RequestInitChain {
  repeated Validator validators =1 [(gogoproto.nullable)=false];
  bytes app_state_bytes = 2;
}

message ResponseInitChain {
  repeated Validator validators = 1 [(gogoproto.nullable)=false];
}

This allows the ABCI protocol to easily support Proof of Stake as well as Proof of Authority (or some other not yet known Proof of XXX).

ref #230

@sunnya97 @jaekwon

[adrianbrink]

ABCI: tendermint/abci#233

[ebuchman]

ABCI now supports this. Need to use it in the app

[mossid]

Is there anybody already working on it?

[mossid]

What happens when RequestInitChain.Validators is empty struct?

[ebuchman]

If it's empty, and the app has no information about the validators from another source, then we basically just need to panic. Eventually this should be a case for ResponseException but that hasn't really been setup