Handle restarts for services in fixturenet-optimism stack (#282)

* Check existing L1 contracts deployment

* Rename volume used for generated L2 config

* Check for existing L2 geth data directory

* Cross check existing L2 config against L1 deployment config

* Verify sequencer key in existing L2 geth data directory

* Add instructions to troubleshoot corrupt L2 geth dir

* Separate out instructions to run L2 with external L1

* Update docs

app/data/container-build/cerc-optimism-contracts/hardhat-tasks/verify-contract-deployment.ts

@@ -0,0 +1,30 @@
+import { task } from 'hardhat/config'
+import '@nomiclabs/hardhat-ethers'
+
+task(
+  'verify-contract-deployment',
+  'Verifies the given contract deployment transaction'
+)
+  .addParam('contract', 'Address of the contract deployed')
+  .addParam('transactionHash', 'Hash of the deployment transaction')
+  .setAction(async ({ contract, transactionHash }, { ethers }) => {
+    const provider = new ethers.providers.JsonRpcProvider(
+      `${process.env.L1_RPC}`
+    )
+
+    // Get the deployment tx receipt
+    const receipt = await provider.getTransactionReceipt(transactionHash)
+    if (
+      receipt &&
+      receipt.contractAddress &&
+      receipt.contractAddress === contract
+    ) {
+      console.log(
+        `Deployment for contract ${contract} in transaction ${transactionHash} verified`
+      )
+      process.exit(0)
+    } else {
+      console.log(`Contract ${contract} deployment verification failed`)
+      process.exit(1)
+    }
+  })