Carbon Axelar Execute Relayer

The purpose of this relayer is to facilitate execution to external chain on Carbon-Axelar bridge. e.g. withdrawals, or any external executions

How it works:

• Watch Switcheo.carbon.bridge.NewPendingActionEvent from Carbon
• Check if fees are profitable for relay (See below)
• If profitable, save Switcheo.carbon.bridge.NewPendingActionEvent record in DB with its nonce
• Call StartRelay on Carbon
• Watch for BridgeRevertedEvent (delete action and stop processing)
• Watch and save Switcheo.carbon.bridge.AxelarCallContractEvent from Carbon where event.nonce matches nonce in DB
• Watch and save ContractCallApproved event from external chain's Axelar Gateway if the payload_hash matches the AxelarCallContractEvent record in the DB
• poll any new event saved,
  • check is_contract_call_approved to see if it's already executed
  • execute to the external blockchain to process the withdrawal or GMP

Note: relayer needs to be whitelisted on carbon

Linux dependencies (only for linux)

# install libssl-dev pkg-config
sudo apt install libssl-dev pkg-config

# install buf
# Substitute BIN for your bin directory.
# Substitute VERSION for the current released version.
BIN="/usr/local/bin" && \
VERSION="1.34.0" && \
curl -sSL \
"https://github.com/bufbuild/buf/releases/download/v${VERSION}/buf-$(uname -s)-$(uname -m)" \
-o "${BIN}/buf" && \
chmod +x "${BIN}/buf"

Setup

Install rust/cargo

follow installation:

• https://www.rust-lang.org/tools/install

then use

rustup install 1.85.1
rustup default 1.85.1

Linux preinstalls

# pre: only if on linux
sudo apt update
sudo apt install build-essential pkg-config libssl-dev -y

Install Postgres

• mac: brew install postgresql@15
• ubuntu: https://www.postgresql.org/download/linux/ubuntu/

Install sqlx

# install sqlx
cargo install sqlx-cli --no-default-features --features native-tls,postgres

Create a .env file and add

# env variable for local development with sqlx (to enable migration etc.)
DATABASE_URL=postgresql://localhost:5432/carbon_axelar_execute_relayer

Setup Database

sqlx database setup

Copy sample config

cp config.sample.toml config.toml

Usage (Binary - Ubuntu)

# download and setup
VERSION=v0.1.1
wget https://github.com/Switcheo/carbon_axelar_execute_relayer/releases/download/$VERSION/carbon_axelar_execute_relayer-x86_64-unknown-linux-gnu.tar.gz
tar -xvzf carbon_axelar_execute_relayer-x86_64-unknown-linux-gnu.tar.gz
chmod +x carbon_axelar_execute_relayer

# run
./carbon_axelar_execute_relayer -vv run

Usage (Dev)

Run without compiling

# run
cargo run -- -vv run

# run with more logs, number of v's:
#        0 => Level::ERROR,
#        1 => Level::WARN,
#        2 => Level::INFO,
#        3 => Level::DEBUG,
#        >3 => Level::TRACE,
cargo run -- -vvvv run

# run with a different config file
cargo run -- --config your_config.toml -vv run

Compile binary

# prepares sqlx for compiling
cargo sqlx prepare -- --bin carbon_axelar_execute_relayer
# compiles to ./target/debug/carbon_axelar_execute_relayer
cargo build
# compiles to ./target/release/carbon_axelar_execute_relayer
cargo build --release

release

# optionally, add release tag to trigger compilation on github
git tag v1.0.0
git push origin v1.0.0

# INFO: Deleting a tag to re-release
git tag -d v1.0.0
git push origin :refs/tags/v1.0.0
git tag v1.0.0
git push origin v1.0.0

Database

# reset database
sqlx database reset
# migrate
sqlx migrate run
# rollback
sqlx migrate revert

# others, use help for more info
sqlx --help
sqlx database --help
sqlx <command> --help

Stuck Transactions

Sometimes transactions get stuck at various points either when a relayer is down or an RPC or WS endpoint is down.

The way to resolve this is to manually call the cli to save the tx since it is missed

# using hex payload
cargo run -- -vv execute-contract-call-approved mantle-testnet 0xcdebbc1eb3895b9d709c0e4f098b8be3ea600fa3c894b0a8c693e012ee501720 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
# using base64 payload, with config file config.develop.toml
cargo run -- --config config.develop.toml -vv execute-contract-call-approved mantle-testnet 0xcdebbc1eb3895b9d709c0e4f098b8be3ea600fa3c894b0a8c693e012ee501720 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA7AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAYAAAAAAAAAAAAAAAAOc69adqgRoWpA/5PqFt/qEMSToOAAAAAAAAAAAAAAAAp2UQC2kn1Lb2oszyaBeY1T4f0QEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQ==

Commands

Resync

# resync from carbon's start block height to end block height to populate missed events so that they can be relayed
cargo run -- -vv sync-from 788086 788099

# resync from carbon's start block height to end block height to populate missed events so that they can be relayed
# specify which block to search for evm events
cargo run -- -vv sync-from 788086 788099

Start Relay

# start a relay on a nonce
cargo run -- -vv start-relay 1

Expire Pending Actions

# expires pending actions by their nonces
cargo run -- -vv expire-pending-actions 1,2,3

Generating protos

Pre-requisite: install buf cli on your computer https://buf.build/docs/cli/installation/

# Note: `cd` into `proto` folder first before running buf
cd proto

# update the proto dependencies in buf.yaml
buf dep update

# generate
buf generate