Support JSON-RPC verifier

[johncantrell97]

• Updates the verifier to rely on both BlockSource and UtxoSource traits which the RestClient and RpcClient both implement. Removing the unnecessary manual implementation of getblockbyhash.
• Introduces an enum AnyChainSource that also implements BlockSource and UtxoSource that the verifier can use.
• Add support for bitcoind JSON-RPC api using the RpcClient.

The default behavior of using RestClient is unchanged. This allows a user to switch to the RpcClient by setting USE_BITCOIN_RPC_API to "true" and providing the various BITCOIN_RPC_* vars (host, port, path, user, password).

[TheBlueMatt]

Oh, can we actually replace most of the ChainVerifier code with the GossipVerifier in lightning-block-sync? It was added here and then mostly upstreamed but never removed here in favor of the upstream version.

[johncantrell97]

Oh, can we actually replace most of the ChainVerifier code with the GossipVerifier in lightning-block-sync? It was added here and then mostly upstreamed but never removed here in favor of the upstream version.

Ah whoops, I thought it was strange this wasn't using that. I assumed there was some important difference. Will give it a shot.

[johncantrell97]

It's appears to be impossible to use GossipVerifier here.

The GossipVerifier assumes your PeerManager will use a P2PGossipSync as your RoutingMessageHandler but RGS PeerManager does not. It uses two of them wrapped in a GossipRouter.

Unless there's some simple way to get around this maybe we can push this change to later?

I could see relaxing the PeerManager constraint on GossipVerifier to be APeerManager or even completely generic RMH but I don't see an easy way to get rid of the P2PGossipSync requirement since in order to resolve the UtxoFuture it calls a method implemented directly on P2PGossipSync and not some method on a trait RGS's router can implement.

edit

Actually, I guess we can give the outbound gossiper to GossipVerifier as the gossiper but still need to a way to relax the PeerManager constraints

edit again

I just opened this to fix this (I think): lightningdevkit/rust-lightning#2773

[jkczyz]

Could we use a type parameter instead of introducing an enum?

[johncantrell97]

Yes, but it bleeds into the entire application and felt unnecessary when RGS is a binary and not really a lib. But I can go back and do this if you think it's better once we resolve the GossipVerifier issues.

[TheBlueMatt]

LGTM. Needs a trivial rebase, however.

[TheBlueMatt]

Any desire to rebase this?