General Governance Updates

Snowbridge has several governance APIs that can only be executed using a democratic process via Polkadot OpenGov.

These APIs include:

• Updating the Gateway contract on Ethereum

• Updating pricing parameters for fee calculations

These APIs are available on the EthereumSystem pallet on BridgeHub. We have also developed a tool for generating calls to these APIs.

Steps for initiating a governance update

As an example, we will show how to upgrade the Gateway contract on Ethereum.

Generate the preimage

Deploy the new gateway contract, and then generate a preimage for calling EthereumSystem.upgrade

snowbridge-preimage --format binary upgrade PARAMS > preimage.bin
 

Test the update in chopsticks

The snowbridge-preimage tool will also generate a helper script chopsticks-execute-upgrade.js to execute the update in simulated chopsticks environment.

1. Run chopsticks and fork Polkadot, AssetHub, and BridgeHub, using these configs

chopsticks xcm -r polkadot.yml -p polkadot-asset-hub.yml -p polkadot-bridge-hub.yml

2. Once the chopsticks environment has been initialized, connect to BridgeHub in Polkadot-JS, and execute the contents of chopsticks-execute-upgrade.js in the Polkadot-JS Javascript console.

A more complicated testing scenario would involve having to upgrade BridgeHub with new code, and then calling a governance API.

OpenGov

The next step involves submitting the proposal to the Whitelisted Caller track in OpenGov.

This actually involves two referendums:

• A referendum on the Collectives chain where the technical fellowship vote to whitelist the preimage.

• A public referendum on Polkadot where the general public vote to execute the whitelisted preimage.

We use the tool opengov-cli to generate the various calls required to setup these referendums.

opengov-cli submit-referendum --proposal preimage.hex --network polkadot --track whitelisted-caller --after 100 --output-len-limit 100 --output AppsUiLink