add hardhat task for withdrawing ETH fees to L1

.changeset/rare-experts-cheat.md

+---
+'@eth-optimism/contracts': patch
+---
+
+Add a hardhat task to withdraw ETH fees from L2 to L1

packages/contracts/README.md

@@ -160,5 +160,23 @@ If you are using a network which Etherscan supports you can verify your contract
 npx hardhat etherscan-verify --api-key ... --network ...
 ```
 
+### Other hardhat tasks
+
+To whitelist deployers on Mainnet you must have the whitelist Owner wallet connected, then run:
+```bash
+npx hardhat whitelist \
+  --use-ledger true \
+  --contracts-rpc-url https://mainnet.optimism.io \
+  --address ... \ # address to whitelist
+```
+
+To withdraw ETH fees to L1 on Mainnet, run:
+```bash
+npx hardhat withdraw-fees \
+  --use-ledger \  # The ledger to withdraw fees with. Ensure this wallet has ETH on L2 to pay the tx fee.
+  --contracts-rpc-url https://mainnet.optimism.io \
+```
+
+
 ## Security
 Please refer to our [Security Policy](https://github.com/ethereum-optimism/.github/security/policy) for information about how to disclose security issues with this code.

packages/contracts/hardhat.config.ts

@@ -17,6 +17,7 @@ import './tasks/deploy'
 import './tasks/l2-gasprice'
 import './tasks/set-owner'
 import './tasks/whitelist'
+import './tasks/withdraw-fees'
 import 'hardhat-gas-reporter'
 
 // Load environment variables from .env

packages/contracts/tasks/set-owner.ts

@@ -63,10 +63,9 @@ task('set-owner')
     console.log(`Owner is currently ${owner.toString()}`)
     console.log(`Setting owner to ${args.owner}`)
 
-    const tx = await Ownable.connect(signer).transferOwnership(
-      args.owner,
-      { gasPrice: args.transactionGasPrice }
-    )
+    const tx = await Ownable.connect(signer).transferOwnership(args.owner, {
+      gasPrice: args.transactionGasPrice,
+    })
 
     const receipt = await tx.wait()
     console.log(`Success - ${receipt.transactionHash}`)

packages/contracts/tasks/withdraw-fees.ts

+'use strict'
+
+import { ethers } from 'ethers'
+import { task } from 'hardhat/config'
+import * as types from 'hardhat/internal/core/params/argumentTypes'
+import { LedgerSigner } from '@ethersproject/hardware-wallets'
+import { getContractFactory } from '../src/contract-defs'
+import { predeploys } from '../src/predeploys'
+
+// Withdraw fees from the FeeVault to L1
+// npx hardhat withdraw-fees --dry-run
+task('withdraw-fees')
+  .addOptionalParam('dryRun', 'simulate withdrawing fees', false, types.boolean)
+  .addOptionalParam(
+    'useLedger',
+    'use a ledger for signing',
+    false,
+    types.boolean
+  )
+  .addOptionalParam(
+    'ledgerPath',
+    'ledger key derivation path',
+    ethers.utils.defaultPath,
+    types.string
+  )
+  .addOptionalParam(
+    'contractsRpcUrl',
+    'Sequencer HTTP Endpoint',
+    process.env.CONTRACTS_RPC_URL,
+    types.string
+  )
+  .addOptionalParam(
+    'privateKey',
+    'Private Key',
+    process.env.CONTRACTS_DEPLOYER_KEY,
+    types.string
+  )
+  .setAction(async (args, hre: any) => {
+    const provider = new ethers.providers.JsonRpcProvider(args.contractsRpcUrl)
+    let signer: ethers.Signer
+    if (!args.useLedger) {
+      if (!args.contractsDeployerKey) {
+        throw new Error('Must pass --contracts-deployer-key')
+      }
+      signer = new ethers.Wallet(args.contractsDeployerKey).connect(provider)
+    } else {
+      signer = new LedgerSigner(provider, 'default', args.ledgerPath)
+    }
+    if (args.dryRun) {
+      console.log('Performing dry run of fee withdrawal...')
+    }
+
+    const l2FeeVault = getContractFactory('OVM_SequencerFeeVault')
+      .connect(signer)
+      .attach(predeploys.OVM_SequencerFeeVault)
+
+    const signerAddress = await signer.getAddress()
+    const signerBalance = await provider.getBalance(signerAddress)
+    const signerBalanceInETH = ethers.utils.formatEther(signerBalance)
+    console.log(
+      `Using L2 signer ${signerAddress} with a balance of ${signerBalanceInETH} ETH`
+    )
+    const l1FeeWallet = await l2FeeVault.l1FeeWallet()
+    const amount = await provider.getBalance(l2FeeVault.address)
+    const amountInETH = ethers.utils.formatEther(amount)
+    console.log(
+      `${
+        args.dryRun ? '[DRY RUN] ' : ''
+      }Withdrawing ${amountInETH} ETH to the L1 address: ${l1FeeWallet}`
+    )
+    if (args.dryRun) {
+      await l2FeeVault.estimateGas.withdraw()
+      return
+    } else {
+      const withdrawTx = await l2FeeVault.withdraw()
+      console.log(
+        `Withdrawal complete: https://optimistic.etherscan.io/tx/${withdrawTx.hash}`
+      )
+      console.log(
+        `Complete withdrawal in 1 week here: https://optimistic.etherscan.io/address/${predeploys.OVM_SequencerFeeVault}#withdrawaltxs`
+      )
+    }
+  })