EXP-83 Create basic scaffolding for bridge core impl (#230)

* feat(bridge): create basic scaffolding (WIP)

* refactor: move bridge-db to db

* chore(bridge): add main fn stubs

* chore(bridge): add bridge binaries to project Cargo.toml

* refactor: move all binaries to bin

This is as per [cargo package
layout](https://doc.rust-lang.org/cargo/guide/project-layout.html)

* fix: correct typo

* refactor: rename rpc-service to rpc-api for consistency

* fix: resolve merge conflict in db crate

* fix: rename bridge crates to use express

* feat(bridge-rpc): create bridge rpc traits

* refactor(bridge-rpc): move bridge-rpc-api inside rpc subdirectory

* refactor(bridge-rpc): move deposit structs into txm and split rpc

* feat(bridge-rpc): bootstrap bridge client in operator mode via stubs

* refactor: remove unnecessary RPCs based on new archi

* fix: remove duplicates after rebase

* feat(bridge-rpc): add basic traits/types

* fix(bridge-exec): move duty to bridge-state to remove cyclic deps

* feat(bridge-txm): create deposit and reimbursement traits

* refactor(bridge-txm): update l2 address type for multiple els

* feat(bridge-exec): lay out types/traits with some basic impl

* revert: move original bins back to root level

Reverts 0efa8579 so as to reduce rebase hell for others.

* fix: udpate struct locations after rebase

* fix(primitives): convert error type for borsh

* refactor(bridge): improve types/traits

This is based on the discussion in PR
[#230](alpenlabs/alpen#230)

* refactor(bridge-rpc): rename `BridgeRpcImpl` to `BridgeRpc`

* refactor(bridge-state): update and use output types for withdrawal

* refactor(bridge-txm): use consistent naming

The `signature_handler` is really a manager and not a handler. The crate
is called `express-bridge-txm`, so the name of the directoy should be
the same.

* refactor(bridge): add `P2PMessage` to duties and remove `DepositRequest`

* chore: reorganize workspace members list

* chore(primitives): remove duplicate deps, add anyhow

* refactor(primitives, state): add TweakedTrKey type for `WithdrawalOutput`

* refactor(primitives): rename `TweakedTrPubkey` to `XOnlyPk`

* refactor(bridge-rpc): update rpc trait

* refactor(bridge-txm): add pubkeys arg to construct deposit tx

* refactor(bridge-exec): remove redundant error display

* refactor(bridge-exec): use AsRef<Path> instead of PathBuf

* refactor(bridge-state): use XOnlyPk for dest_pk

* chore: sort workspace members

* refactor(bridge-client): convert `mode` to positional arg

* refactor(bridge-rpc): rename method

* refactor(bridge-exec): remove challenger exec

* fix(bridge-exec): convert methods to pure funcs and remove relay methods

* refactor(bridge-exec): remove pk path from config

* refactor: implement Deref/DerefMut for BitcoinAmount

* refactor: convert version to an enum

* refactor(bridge-exec): use NetworkChecked addr

* Revert "refactor: implement Deref/DerefMut for BitcoinAmount"

This reverts commit 96aec67910f0f0f1d2f2ce5530e024c741adf2e7.

* chore: cleanup unused imports

* fix: resolve rebase issue

* refactor(bridge-client): replace clap with argh

:(

* chore(bridge-rpc): add TODO to refactor RPCs

* chore(withdrawal-handler): update PR reference

* refactor(bridge-txm): split crate into builder and signer

* refactor(bridge-exec): change signatures based on new types

* docs(bridge-client): add note on using `express-tasks`

* refactor(bridge-rpc): use new types

* refactor(bridge-state): change type definitions for consistency

* refactor(bridge-exec): use proper error messages

* feat(primitives): add bridge primitives

* feat(primitives): add concrete error types

Author: neon-smith-tsmmn

Cargo.lock

@@ -1,5 +1,8 @@
 [workspace]
 members = [
+  "crates/bridge-exec",
+  "crates/bridge-sig-manager",
+  "crates/bridge-tx-builder",
   "crates/btcio",
   "crates/chaintsn",
   "crates/common",
@@ -19,6 +22,7 @@ members = [
   "crates/reth/node",
   "crates/reth/rpc",
   "crates/rpc/api",
+  "crates/rpc/bridge-api",
   "crates/rpc/types",
   "crates/rpc/utils",
   "crates/state",
@@ -32,11 +36,12 @@ members = [
   "proofs/sp1",
 
   # binaries listed separately
-  "sequencer",
+  "bin/bridge-client",
   "reth",
+  "sequencer",
 ]
 
-default-members = ["sequencer", "reth"]
+default-members = ["bin/bridge-client", "reth", "sequencer"]
 
 resolver = "2"
 
@@ -56,6 +61,10 @@ alpen-express-state = { path = "crates/state" }
 alpen-express-status = { path = "crates/status" }
 alpen-test-utils = { path = "crates/test-utils" }
 bitcoin-blockspace = { path = "crates/prover/bitcoin-blockspace" }
+express-bridge-exec = { path = "crates/bridge-exec" }
+express-bridge-rpc-api = { path = "crates/rpc/bridge-api" }
+express-bridge-sig-manager = { path = "crates/bridge-sig-manager" }
+express-bridge-tx-builder = { path = "crates/bridge-tx-builder" }
 express-chaintsn = { path = "crates/chaintsn" }
 express-reth-db = { path = "crates/reth/db" }
 express-reth-exex = { path = "crates/reth/exex" }
@@ -83,6 +92,7 @@ bitcoind = { version = "0.36.0", features = ["26_0"] }
 bitcoind-json-rpc-types = "0.3.0"
 borsh = { version = "1.5.0", features = ["derive"] }
 bytes = { version = "1.6.0" }
+chrono = { version = "0.4.38" }
 digest = "0.10"
 eyre = "0.6"
 format_serde_error = { git = "https://github.com/AlexanderThaller/format_serde_error" }

Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+edition = "2021"
+name = "express-bridge-client"
+version = "0.1.0"
+
+[[bin]]
+name = "express-bridge-client"
+path = "src/main.rs"
+
+[dependencies]
+alpen-express-common = { workspace = true }
+express-bridge-rpc-api = { workspace = true }
+
+anyhow = { workspace = true }
+argh = { workspace = true }
+async-trait = { workspace = true }
+bitcoin = { workspace = true }
+chrono = { workspace = true }
+jsonrpsee = { workspace = true }
+thiserror = { workspace = true }
+tokio = { workspace = true }
+tracing = { workspace = true }
+tracing-subscriber = { workspace = true, features = ["env-filter"] }

bin/bridge-client/Cargo.toml

@@ -0,0 +1,47 @@
+//! Parses command-line arguments for the bridge-client CLI.
+use std::fmt::Display;
+
+use argh::FromArgs;
+
+use crate::errors::InitError;
+
+#[derive(Debug, FromArgs)]
+#[argh(name = "express-bridge-client")]
+#[argh(description = "The bridge client for Express")]
+pub(crate) struct Cli {
+    #[argh(
+        positional,
+        description = "what mode to run the client in, either Operator (alias: op) or Challenger (alias: ch)"
+    )]
+    pub mode: String,
+}
+
+#[derive(Debug, Clone)]
+pub(super) enum OperationMode {
+    /// Run client in Operator mode to handle deposits, withdrawals and challenging.
+    Operator,
+
+    /// Run client in Challenger mode to verify/challenge Operator claims.
+    Challenger,
+}
+
+impl Display for OperationMode {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            OperationMode::Operator => write!(f, "operator"),
+            OperationMode::Challenger => write!(f, "challenger"),
+        }
+    }
+}
+
+impl TryInto<OperationMode> for String {
+    type Error = InitError;
+
+    fn try_into(self) -> Result<OperationMode, Self::Error> {
+        match self.as_ref() {
+            "operator" | "op" => Ok(OperationMode::Operator),
+            "challenger" | "ch" => Ok(OperationMode::Challenger),
+            other => Err(InitError::InvalidMode(other.to_string())),
+        }
+    }
+}

bin/bridge-client/src/args.rs

@@ -0,0 +1,2 @@
+pub(super) const RPC_PORT: usize = 4781; // first 4 digits in the sha256 of "operator"
+pub(super) const RPC_SERVER: &str = "127.0.0.1";

bin/bridge-client/src/constants.rs

@@ -0,0 +1,7 @@
+use thiserror::Error;
+
+#[derive(Debug, Clone, Error)]
+pub enum InitError {
+    #[error("Invalid operation mode, expected: operator(op) or challenger(ch), got: {0}")]
+    InvalidMode(String),
+}

bin/bridge-client/src/errors.rs

@@ -0,0 +1,42 @@
+//! Bridge Operator client.
+//!
+//! Responsible for facilitating bridge-in and bridge-out operations by creating, storing and
+//! publishing appropriate transactions. Can also perform challenger duties.
+
+mod args;
+pub(crate) mod constants;
+mod errors;
+mod modes;
+pub(crate) mod rpc_server;
+
+use alpen_express_common::logging;
+use args::{Cli, OperationMode};
+use modes::{challenger, operator};
+use tracing::info;
+
+#[tokio::main]
+async fn main() {
+    logging::init();
+
+    let cli_args: Cli = argh::from_env();
+
+    let mode: OperationMode = match cli_args.mode.try_into() {
+        Ok(mode) => mode,
+        Err(err) => {
+            panic!("{}", err);
+        }
+    };
+
+    info!("running bridge client in {} mode", mode);
+
+    match mode {
+        OperationMode::Operator => {
+            operator::bootstrap()
+                .await
+                .expect("bootstrap operator node");
+        }
+        OperationMode::Challenger => {
+            challenger::bootstrap().await;
+        }
+    }
+}

bin/bridge-client/src/main.rs

@@ -0,0 +1,5 @@
+//! Defines the main loop for the bridge-client in challenger mode.
+
+pub(crate) async fn bootstrap() {
+    unimplemented!("Challenger mode");
+}

bin/bridge-client/src/modes/challenger/mod.rs

@@ -0,0 +1,4 @@
+//! Defines the main loops for bridge-client modes namely, `operator` and `challenger`.
+
+pub(crate) mod challenger;
+pub(crate) mod operator;

bin/bridge-client/src/modes/mod.rs

@@ -0,0 +1,14 @@
+//! Defines the main loop for the bridge-client in operator mode.
+
+use crate::rpc_server::{self, BridgeRpc};
+
+/// Bootstraps the bridge client in Operator mode by hooking up all the required auxiliary services
+/// including database, rpc server, etc. Threadpool and logging need to be initialized at the call
+/// site (main function) itself.
+pub(crate) async fn bootstrap() -> anyhow::Result<()> {
+    let rpc_impl = BridgeRpc::default();
+
+    rpc_server::start(&rpc_impl).await?;
+
+    Ok(())
+}