# WIP: The Relay Chain Guide Guide on manually setting up Rococo Relay chain for development purposes. ### Prerequisites You should be comfortable with the following tutorial: - https://docs.substrate.io/tutorials/build-a-blockchain/add-trusted-nodes ## Setup Clone, checkout, build Polkadot: ``` git clone https://github.com/paritytech/polkadot cd polkadot git checkout release-v0.9.37 cargo b -r ``` ## Generate Keys Use Substrate's key command to generate a random secret phrase and Sr25519 keys (for BABE): > You will need to clone and compile [Substrate](https://github.com/paritytech/substrate) for this: ``` ./target/release/substrate key generate --scheme Sr25519 --password-interactive ``` Type a password. Output will be similar to: ``` Secret phrase: pig giraffe ceiling enter weird liar orange decline behind total despair fly Secret seed: 0x0087016ebbdcf03d1b7b2ad9a958e14a43f2351cd42f2f0a973771b90fb0112f Public key (hex): 0x1a4cc824f6585859851f818e71ac63cf6fdc81018189809814677b2a4699cf45 Account ID: 0x1a4cc824f6585859851f818e71ac63cf6fdc81018189809814677b2a4699cf45 Public key (SS58): 5CfBuoHDvZ4fd8jkLQicNL8tgjnK8pVG9AiuJrsNrRAx6CNW SS58 Address: 5CfBuoHDvZ4fd8jkLQicNL8tgjnK8pVG9AiuJrsNrRAx6C ``` Use the secret phrase to derive Ed25519 keys (for GRANDPA): ``` ./target/release/substrate key inspect --password-interactive --scheme Ed25519 "pig giraffe ceiling enter weird liar orange decline behind total despair fly" ``` Type the password used to generate the keys. Output will be similar to: ``` Secret phrase `pig giraffe ceiling enter weird liar orange decline behind total despair fly` is account: Secret seed: 0x0087016ebbdcf03d1b7b2ad9a958e14a43f2351cd42f2f0a973771b90fb0112f Public key (hex): 0x2577ba03f47cdbea161851d737e41200e471cd7a31a5c88242a527837efc1e7b Public key (SS58): 5CuqCGfwqhjGzSqz5mnq36tMe651mU9Ji8xQ4JRuUTvPcjVN Account ID: 0x2577ba03f47cdbea161851d737e41200e471cd7a31a5c88242a527837efc1e7b SS58 Address: 5CuqCGfwqhjGzSqz5mnq36tMe651mU9Ji8xQ4JRuUTvPcjV ``` Generate a second set of keys. ## Generate the chain specs If we generate the below chain spec we will get a bunch of dev keys. ``` ./target/release/polkadot build-spec --disable-default-bootnode --chain rococo-local > rococoLocalCustomSpec.json ``` We could ignore and insert our own custom keys. OR - https://substrate.stackexchange.com/questions/8180/how-to-create-a-polkadot-chain-spec-for-development-purposes We can edit the `chain_spec.rs` file, specifically this: ```rust #[cfg(feature = "rococo-native")] fn rococo_local_testnet_genesis(wasm_binary: &[u8]) -> rococo_runtime::GenesisConfig { rococo_testnet_genesis( wasm_binary, vec![get_authority_keys_from_seed("Alice"), get_authority_keys_from_seed("Bob")], get_account_id_from_seed::<sr25519::Public>("Alice"), None, ) } ``` - https://github.com/paritytech/polkadot/blob/a6cfdb16e9a69259ee824fa0aa60c36e4c63f3fa/node/service/src/chain_spec.rs#L1886-L1894 We can change to this: ```rust #[cfg(feature = "rococo-native")] fn rococo_local_testnet_genesis(wasm_binary: &[u8]) -> rococo_runtime::GenesisConfig { rococo_testnet_genesis( wasm_binary, vec![], get_account_id_from_seed::<sr25519::Public>("Alice"), None, ) } ``` Also, change this: ```rust let endowed_accounts: Vec<AccountId> = endowed_accounts.unwrap_or_else(testnet_accounts); ``` To this: ``` let endowed_accounts: Vec<AccountId> = vec![]; ``` - https://github.com/paritytech/polkadot/blob/a6cfdb16e9a69259ee824fa0aa60c36e4c63f3fa/node/service/src/chain_spec.rs#L1557 We can now create our rococo-local "empty" accounts chain spec: ``` ./target/release/polkadot build-spec --disable-default-bootnode --chain rococo-local > rococoLocalCustomSpec.json ``` ## Insert our keys ## Start the Relay chain ``` ./target/release/polkadot \ --alice \ --validator \ --base-path /tmp/relay/alice \ --chain /tmp/raw-local-chainspec.json \ --port 30333 \ --ws-port 9944 ```