Chain upgrade

Performs a chain upgrade using the sudo module. This may brick your chain, so use it as an educational sample. (use substrate purge-chain --dev to remove DB and recover).

// Import the API & Provider and some utility functions

const { ApiPromise, WsProvider } = require('@polkadot/api');

// import the test keyring (already has dev keys for Alice, Bob, Charlie, Eve & Ferdie)

const testKeyring = require('@polkadot/keyring/testing');

const fs = require('fs');

async function main () {

// Initialise the provider to connect to the local node

const provider = new WsProvider('ws://127.0.0.1:9944');

// Create the API and wait until ready (optional provider passed through)

const api = await ApiPromise.create({ provider });

// Retrieve the upgrade key from the chain state

const adminId = await api.query.sudo.key();

// Find the actual keypair in the keyring (if this is a changed value, the key

// needs to be added to the keyring before - this assumes we have defaults, i.e.

// Alice as the key - and this already exists on the test keyring)

const keyring = testKeyring.default();

const adminPair = keyring.getPair(adminId.toString());

// Retrieve the runtime to upgrade

const code = fs.readFileSync('./test.wasm').toString('hex');

const proposal = api.tx.system && api.tx.system.setCode

? api.tx.system.setCode(`0x${code}`) // For newer versions of Substrate

: api.tx.consensus.setCode(`0x${code}`); // For previous versions

console.log(`Upgrading from ${adminId}, ${code.length / 2} bytes`);

// Perform the actual chain upgrade via the sudo module

api.tx.sudo

.sudo(proposal)

.signAndSend(adminPair, ({ events = [], status }) => {

console.log('Proposal status:', status.type);

if (status.isInBlock) {

console.error('You have just upgraded your chain');

console.log('Included at block hash', status.asInBlock.toHex());

console.log('Events:');

console.log(JSON.stringify(events.toHuman(), null, 2));

} else if (status.isFinalized) {

console.log('Finalized block hash', status.asFinalized.toHex());

process.exit(0);

}

});

}

main().catch((error) => {

console.error(error);

process.exit(-1);

});