Improve Relayer Initialization Behaviour

[HCastano]

Right now the relayer claims to have succesfully initialized the bridge pallet when it
fires off a transaction to a node. However, if the node rejects the transactions (if for
example the init request was submitted with the wrong owner) the relayer has no way of
knowing that its initialization request failed.

We should do two things:

1. Tweak the wording of the initialization log message to indicate that the bridge might
   not actually be initialized yet (just that the tx was submitted)
2. Wait for a couple of seconds and follow up with the node to see if the transaction was
   succesful
   • We may need to have the runtime emit an initialized event which the relayer can
     listen for

[bkontur]

I am working on bridging Rococo vs Wococo BridgeHubs. I was testing first step init-bridge,
the result in the log was like this:

~/local_bridge_testing$ RUST_LOG=runtime=trace,rpc=trace,runtime::bridge=trace \
>  ~/local_bridge_testing/bin/substrate-relay init-bridge bridge-hub-rococo-to-bridge-hub-wococo \
> --source-host localhost \
> --source-port 48943 \
> --target-host localhost \
> --target-port 8945 \
> --target-signer //Alice
2022-08-22 14:38:59 +00 INFO bridge Connecting to BridgeHubRococo node at ws://localhost:48943
2022-08-22 14:38:59 +00 INFO bridge Connecting to BridgeHubWococo node at ws://localhost:8945
2022-08-22 14:39:07 +00 INFO bridge Prepared initialization data for BridgeHubRococo-headers bridge at BridgeHubWococo: InitializationData { header: Header { parent_hash: 0x14ea0c9aac970855233352a2a09d87814c5b4d2d539e6f17513779617cde74c0, number: 1089, state_root: 0xff1117cd7ed7680316305bfb31997d0ab592ab636108a234e26f27a32ae0616a, extrinsics_root: 0x582209f4a3d3322cc22f8e95ead105fdf30b14bd5915e4002905dbea40f5b6c4, digest: Digest { logs: [DigestItem::PreRuntime([66, 65, 66, 69], [1, 0, 0, 0, 0, 212, 152, 128, 16, 0, 0, 0, 0, 178, 44, 139, 150, 149, 32, 229, 19, 142, 139, 101, 21, 209, 193, 102, 219, 209, 117, 251, 93, 236, 222, 43, 3, 116, 245, 175, 228, 99, 234, 16, 99, 11, 197, 17, 69, 80, 116, 162, 65, 224, 186, 89, 6, 48, 12, 180, 220, 158, 247, 32, 110, 61, 106, 100, 46, 238, 31, 153, 118, 176, 50, 251, 12, 220, 3, 75, 74, 18, 162, 247, 148, 231, 187, 43, 104, 100, 134, 103, 229, 139, 135, 136, 182, 50, 107, 189, 61, 198, 186, 24, 54, 26, 48, 255, 12]), DigestItem::Consensus([66, 69, 69, 70], [3, 24, 225, 61, 100, 40, 28, 191, 132, 12, 4, 215, 255, 145, 151, 186, 219, 104, 89, 167, 134, 252, 125, 51, 152, 77, 192, 234, 131, 229, 93, 234, 207]), DigestItem::Seal([66, 65, 66, 69], [96, 228, 18, 227, 190, 128, 221, 147, 90, 248, 85, 191, 21, 183, 55, 139, 80, 219, 58, 135, 105, 255, 122, 115, 132, 182, 225, 85, 126, 176, 254, 53, 235, 225, 205, 241, 40, 152, 176, 188, 116, 196, 165, 250, 7, 155, 149, 225, 123, 49, 119, 195, 219, 141, 102, 192, 28, 210, 46, 174, 114, 54, 26, 132])] } }, authority_list: [(Public(88dc3417d5058ec4b4503e0c12ea1a0a89be200fe98922423d4334014fa6b0ee (5FA9nQDV...)), 1), (Public(d17c2d7823ebf260fd138f2d7e27d114c0145d968b5ff5006125f2414fadae69 (5GoNkf6W...)), 1)], set_id: 107, operating_mode: BasicOperatingMode::Normal }
2022-08-22 14:39:07 +00 INFO bridge Successfully submitted BridgeHubRococo-headers bridge initialization transaction to BridgeHubWococo: 0xf95d4b514cc9418574439febe5d69354444dec0a1bdbb9db279baa50ece64478

so I was very happy, that it worked, but I was checking bridge pallets state and nothing happens,
so I check block with included extrinsic, and it was system.ExtrinsicError with BadOrigin.

Anyway, it navigated me to learn about Accounts and how to setup correctly owner or sudo on runtime and so on. And now it is working between bridge hubs.

So when, things worked for me, I came back to my problem with BadOrigin, how to fix it better, and I found
https://github.com/paritytech/parity-bridges-common/blob/master/relays/bin-substrate/src/cli/register_parachain.rs#L271-L274,
so for do_initialize I tried to change submit_signed_extrinsic to submit_and_watch_signed_extrinsic and wait for transaction finalization in to the block with wait_until_transaction_is_finalized, it worked, here is the log:

~/local_bridge_testing$ RUST_LOG=runtime=trace,rpc=trace,runtime::bridge=trace  ~/local_bridge_testing/bin/substrate-relay init-bridge bridge-hub-rococo-to-bridge-hub-wococo --source-host localhost --source-port 48943 --target-host localhost --target-port 8945 --target-signer //Bob
2022-08-24 19:48:08 +00 INFO bridge Connecting to BridgeHubRococo node at ws://localhost:48943
2022-08-24 19:48:08 +00 INFO bridge Connecting to BridgeHubWococo node at ws://localhost:8945
2022-08-24 19:48:12 +00 INFO bridge Prepared initialization data for BridgeHubRococo-headers bridge at BridgeHubWococo: InitializationData { header: Header { parent_hash: 0x193548fc1755765e0653803909590d2000d0b8234fb1f38b9ed417cbf8a755b1, number: 140, state_root: 0x4ea939e9987dc49b219bed4c7e1341f6e4ec1b9c2e438c4f46c16cb2151bcf49, extrinsics_root: 0xf9596bf7dcf90d8cdb299e0290bc18f52ca9364860905b77451fb5ac229d1578, digest: Digest { logs: [DigestItem::PreRuntime([66, 65, 66, 69], [3, 1, 0, 0, 0, 103, 21, 129, 16, 0, 0, 0, 0, 162, 17, 51, 225, 50, 220, 9, 99, 72, 72, 152, 254, 94, 183, 140, 229, 27, 82, 160, 51, 240, 67, 43, 47, 229, 203, 106, 60, 27, 85, 79, 100, 160, 166, 234, 128, 92, 135, 121, 21, 59, 184, 36, 69, 160, 188, 184, 247, 71, 21, 237, 208, 45, 181, 148, 173, 109, 235, 214, 120, 189, 12, 216, 10, 237, 176, 155, 143, 151, 17, 61, 220, 90, 107, 123, 81, 161, 253, 156, 133, 35, 245, 221, 222, 191, 135, 74, 182, 132, 89, 241, 223, 137, 159, 247, 15]), DigestItem::Consensus([66, 69, 69, 70], [3, 76, 72, 41, 253, 67, 150, 242, 89, 234, 199, 172, 235, 225, 4, 92, 96, 237, 117, 2, 127, 42, 54, 28, 17, 8, 44, 61, 218, 224, 253, 228, 127]), DigestItem::Seal([66, 65, 66, 69], [6, 124, 203, 205, 136, 122, 237, 132, 180, 70, 153, 148, 6, 226, 235, 66, 143, 156, 243, 181, 223, 45, 49, 255, 157, 1, 27, 212, 11, 50, 161, 114, 191, 38, 170, 38, 215, 69, 173, 14, 220, 159, 180, 197, 105, 152, 3, 200, 253, 150, 49, 201, 117, 115, 229, 133, 245, 79, 78, 205, 113, 180, 150, 142])] } }, authority_list: [(Public(88dc3417d5058ec4b4503e0c12ea1a0a89be200fe98922423d4334014fa6b0ee (5FA9nQDV...)), 1), (Public(d17c2d7823ebf260fd138f2d7e27d114c0145d968b5ff5006125f2414fadae69 (5GoNkf6W...)), 1)], set_id: 12, operating_mode: BasicOperatingMode::Normal }
2022-08-24 19:48:12 +00 WARN jsonrpsee_core::client::async_client::helpers Subscription ID: Str("sbMfqxXFlzFGQWVo") is not an active subscription
2022-08-24 19:48:12 +00 INFO bridge Received intermediate status of BridgeHubWococo transaction: Some(Broadcast(["12D3KooWJuHZCHtpyRoDyrUNwjkd8zowEXDpH9mUrgceBZaGZuh1", "12D3KooWL8Cjg1WniKwXork19T8LJw2xJRBifNMwpC7C18r5fttm", "12D3KooWLHAehvC6SubAiUP9kJvekuE4dm2KASNjDcQJ8w1fTruj"]))
2022-08-24 19:48:30 +00 INFO bridge Received intermediate status of BridgeHubWococo transaction: Some(InBlock(0x1c6fb2d167a7ffaff369e3417bd38ed9c0d86f02b9bc8c12b68092c4610a8b1c))
2022-08-24 19:48:53 +00 INFO bridge BridgeHubWococo transaction has been finalized at block 0x1c6f…8b1c
2022-08-24 19:48:53 +00 INFO bridge Result: Ok(0x1c6fb2d167a7ffaff369e3417bd38ed9c0d86f02b9bc8c12b68092c4610a8b1c)
2022-08-24 19:48:53 +00 INFO bridge Successfully submitted BridgeHubRococo-headers bridge initialization transaction to BridgeHubWococo: 0x1c6fb2d167a7ffaff369e3417bd38ed9c0d86f02b9bc8c12b68092c4610a8b1c

But this is also not enought, because we dont see the result of transaction, just the hash of the finalized block, because the transaction can have system.ExtrinsicError or system.ExtrinsicSuccess.

So the ultimate check could be: after transaction is finalized at some block, just to do a one RPC/WS call to target chain to check the header with transaction and the extrinsic result.

This is exactly something like the 2. point from description and I thing we dont need to trigger another specific Event initilized, maybe that system.ExtrinsicError/ExtrinsicSuccess check is enought.

@HCastano @svyatonik
guys, is this still relevant/worth? What do you suggest for fix?

I would love to take it as a one of "good first issue" also :)

[svyatonik]

@bkontur There are two options: to check for ExtrinsicError/ExtrinsicSuccess and to check for the side effects of the transaction (e.g. for initialization tx it would be the check that the pallet is actually initialized). Imo first is better

[serban300]

@bkontur are you still working on this ? If not, I would be interested in taking a look.

[bkontur]

@serban300 sure, just take it. I guess, it is not a really prio, because we use 'init-bridge' cmd only for local or rialto/millau run, for live Rococo/Wococo or Kusama/Polkadot we trigger init-bridge logic by "root" governance calls and not by relayer

[serban300]

Thanks Branislav ! Ok, I'll take it then.