council-integration.md

How to use the Validator Set pallet with Collective pallet as origin

Setup

1. Import and declare the Collective pallet in your runtime. Make sure to import the required traits.

parameter_types! {
	pub const CouncilMotionDuration: BlockNumber = 3 * MINUTES;
	pub const CouncilMaxProposals: u32 = 100;
	pub const CouncilMaxMembers: u32 = 100;
}

impl pallet_collective::Config for Runtime {
	type Origin = Origin;
	type Proposal = Call;
	type Event = Event;
	type MotionDuration = CouncilMotionDuration;
	type MaxProposals = CouncilMaxProposals;
	type MaxMembers = CouncilMaxMembers;
	type DefaultVote = pallet_collective::PrimeDefaultVote;
	type WeightInfo = pallet_collective::weights::SubstrateWeight<Runtime>;
}

2. Setup a custom origin using the Collective pallet. In the example below, we have a custom origin that ensures either root or at least half of the collective's approval.

type EnsureRootOrHalfCouncil = EnsureOneOf<
	AccountId,
	EnsureRoot<AccountId>,
	pallet_collective::EnsureProportionAtLeast<1, 2, AccountId>
>;

3. Configure the custom origin for the Validator Set pallet.

impl validator_set::Config for Runtime {
	type Event = Event;
	type MinAuthorities = MinAuthorities; // see readme for type declaration
	type AddRemoveOrigin = EnsureRootOrHalfCouncil;
}

4. Add genesis config for the Collective pallet to initialize some members in the collective when the chain starts. In the example below, the initial authorities are also the collective members. (The Collective pallet's default instance is named as council here.)

council: CouncilConfig {
    members: initial_authorities.iter().map(|x| x.0.clone()).collect::<Vec<_>>(),
    phantom: Default::default(),
},

For rest of the setup steps, see readme.md.

Run

Before running - Alice and Bob are set as initial authorities and also as council members.

• Start the chain in the local_testnet mode with the non-validator (--charlie) first (so it take the default port and connects with the Polkadot JS web app).
• Start --alice and --bob nodes too.
• Alice and Bob will produce blocks and Charlie will only import them as it is not a validator yet.
• From Charlie's node connected web app instance, make an RPC call author - rotate_keys. This will print session keys for Charlie node.
• Use this printed string in the step 4 and make an extrinsic call from Charlie account - Session - set_keys. Put 0x in the proof input.
• Now start the council flow. From Alice propose a motion to add Charlie as a validator using the validator-set pallet.
• From Bob account, vote and approve this proposal.
• Wait for the voting period to end. Close the motion using Alice account.
• The motion will execute and Charlie will be added as validator. (see screenshot below)