feat(mon): Add withdrawal monitor to chain-mon

.changeset/wet-files-knock.md

@@ -0,0 +1,5 @@
+---
+'@eth-optimism/chain-mon': patch
+---
+
+Added withdrawal monitoring to identify proven withdrawals not included in the L2ToL1MessagePasser's sentMessages mapping

packages/chain-mon/.env.example

@@ -7,3 +7,14 @@ DRIPPIE_MON__RPC=
 
 # Address of the Drippie contract
 DRIPPIE_MON__DRIPPIE_ADDRESS=
+
+###############################################################################
+#                                  ↓  wd-mon  ↓                               #
+###############################################################################
+
+# RPCs pointing to a base chain and ptimism chain
+TWO_STEP_MONITOR__L1_RPC_PROVIDER=
+TWO_STEP_MONITOR__L2_RPC_PROVIDER=
+
+# The block number to start monitoring from
+TWO_STEP_MONITOR__START_BLOCK_NUMBER=

packages/chain-mon/package.json

@@ -10,6 +10,7 @@
   ],
   "scripts": {
     "start:drippie-mon": "ts-node ./src/drippie-mon/service.ts",
+    "start:wd-mon": "ts-node ./src/wd-mon/service.ts",
     "test:coverage": "echo 'No tests defined.'",
     "build": "tsc -p ./tsconfig.json",
     "clean": "rimraf  dist/ ./tsconfig.tsbuildinfo",
@@ -35,7 +36,10 @@
     "@eth-optimism/contracts-periphery": "1.0.7",
     "@eth-optimism/core-utils": "0.12.0",
     "@eth-optimism/sdk": "1.10.1",
-    "ethers": "^5.7.0"
+    "ethers": "^5.7.0",
+    "@types/dateformat": "^5.0.0",
+    "chai-as-promised": "^7.1.1",
+    "dateformat": "^4.5.1"
   },
   "devDependencies": {
     "@ethersproject/abstract-provider": "^5.7.0",

packages/chain-mon/src/index.ts

@@ -1 +1,2 @@
 export * from './drippie-mon/service'
+export * from './wd-mon/service'

packages/chain-mon/src/wd-mon/service.ts

@@ -0,0 +1,232 @@
+import {
+  BaseServiceV2,
+  StandardOptions,
+  ExpressRouter,
+  Gauge,
+  validators,
+  waitForProvider,
+} from '@eth-optimism/common-ts'
+import { CrossChainMessenger } from '@eth-optimism/sdk'
+import { getChainId, sleep } from '@eth-optimism/core-utils'
+import { Provider } from '@ethersproject/abstract-provider'
+import { Event } from 'ethers'
+import dateformat from 'dateformat'
+
+import { version } from '../../package.json'
+
+type Options = {
+  l1RpcProvider: Provider
+  l2RpcProvider: Provider
+  startBlockNumber: number
+  sleepTimeMs: number
+}
+
+type Metrics = {
+  withdrawalsValidated: Gauge
+  isDetectingForgeries: Gauge
+  nodeConnectionFailures: Gauge
+}
+
+type State = {
+  messenger: CrossChainMessenger
+  highestUncheckedBlockNumber: number
+  finalizationWindow: number
+  forgeryDetected: boolean
+}
+
+export class WithdrawalMonitor extends BaseServiceV2<Options, Metrics, State> {
+  constructor(options?: Partial<Options & StandardOptions>) {
+    super({
+      version,
+      name: 'two-step-monitor',
+      loop: true,
+      options: {
+        loopIntervalMs: 1000,
+        ...options,
+      },
+      optionsSpec: {
+        l1RpcProvider: {
+          validator: validators.provider,
+          desc: 'Provider for interacting with L1',
+        },
+        l2RpcProvider: {
+          validator: validators.provider,
+          desc: 'Provider for interacting with L2',
+        },
+        startBlockNumber: {
+          validator: validators.num,
+          default: -1,
+          desc: 'L1 block number to start checking from',
+          public: true,
+        },
+        sleepTimeMs: {
+          validator: validators.num,
+          default: 15000,
+          desc: 'Time in ms to sleep when waiting for a node',
+          public: true,
+        },
+      },
+      metricsSpec: {
+        withdrawalsValidated: {
+          type: Gauge,
+          desc: 'Latest L1 Block (checked and known)',
+          labels: ['type'],
+        },
+        isDetectingForgeries: {
+          type: Gauge,
+          desc: '0 if state is ok. 1 or more if forged withdrawals are detected.',
+        },
+        nodeConnectionFailures: {
+          type: Gauge,
+          desc: 'Number of times node connection has failed',
+          labels: ['layer', 'section'],
+        },
+      },
+    })
+  }
+
+  async init(): Promise<void> {
+    // Connect to L1.
+    await waitForProvider(this.options.l1RpcProvider, {
+      logger: this.logger,
+      name: 'L1',
+    })
+
+    // Connect to L2.
+    await waitForProvider(this.options.l2RpcProvider, {
+      logger: this.logger,
+      name: 'L2',
+    })
+
+    this.state.messenger = new CrossChainMessenger({
+      l1SignerOrProvider: this.options.l1RpcProvider,
+      l2SignerOrProvider: this.options.l2RpcProvider,
+      l1ChainId: await getChainId(this.options.l1RpcProvider),
+      l2ChainId: await getChainId(this.options.l2RpcProvider),
+    })
+
+    // Not detected by default.
+    this.state.forgeryDetected = false
+
+    // For now we'll just start take it from the env or the tip of the chain
+    if (this.options.startBlockNumber === -1) {
+      this.state.highestUncheckedBlockNumber =
+        await this.options.l1RpcProvider.getBlockNumber()
+    } else {
+      this.state.highestUncheckedBlockNumber = this.options.startBlockNumber
+    }
+
+    this.logger.info(`starting L1 block height`, {
+      startBlockNumber: this.state.highestUncheckedBlockNumber,
+    })
+  }
+
+  // K8s healthcheck
+  async routes(router: ExpressRouter): Promise<void> {
+    router.get('/healthz', async (req, res) => {
+      return res.status(200).json({
+        ok: !this.state.forgeryDetected,
+      })
+    })
+  }
+
+  async main(): Promise<void> {
+    // Get current block number
+    let latestL1BlockNumber: number
+    try {
+      latestL1BlockNumber = await this.options.l1RpcProvider.getBlockNumber()
+    } catch (err) {
+      this.logger.error(`got error when connecting to node`, {
+        error: err,
+        node: 'l1',
+        section: 'getBlockNumber',
+      })
+      this.metrics.nodeConnectionFailures.inc({
+        chainId: this.state.messenger.l1ChainId,
+        section: 'getBlockNumber',
+      })
+      await sleep(this.options.sleepTimeMs)
+      return
+    }
+
+    // See if we have a new unchecked block
+    if (latestL1BlockNumber <= this.state.highestUncheckedBlockNumber) {
+      // The RPC provider is behind us, wait a bit
+      await sleep(this.options.sleepTimeMs)
+      return
+    }
+
+    this.logger.info(`checking recent blocks`, {
+      fromBlockNumber: this.state.highestUncheckedBlockNumber,
+      toBlockNumber: latestL1BlockNumber,
+    })
+
+    // Perform the check
+    let proofEvents: Event[]
+    try {
+      // The query includes events in the blockNumbers given as the last two arguments
+      proofEvents =
+        await this.state.messenger.contracts.l1.OptimismPortal.queryFilter(
+          this.state.messenger.contracts.l1.OptimismPortal.filters.WithdrawalProven(),
+          this.state.highestUncheckedBlockNumber,
+          latestL1BlockNumber
+        )
+    } catch (err) {
+      this.logger.error(`got error when connecting to node`, {
+        error: err,
+        node: 'l1',
+        section: 'querying for WithdrawalProven events',
+      })
+      this.metrics.nodeConnectionFailures.inc({
+        layer: 'l1',
+        section: 'querying for WithdrawalProven events',
+      })
+      // connection error, wait then restart
+      await sleep(this.options.sleepTimeMs)
+      return
+    }
+
+    for (const proofEvent of proofEvents) {
+      const exists =
+        await this.state.messenger.contracts.l2.BedrockMessagePasser.sentMessages(
+          proofEvent.args.withdrawalHash
+        )
+      const provenAt = `${
+        (dateformat(
+          new Date(
+            (await this.options.l1RpcProvider.getBlock(proofEvent.blockHash))
+              .timestamp * 1000
+          )
+        ),
+        'mmmm dS, yyyy, h:MM:ss TT',
+        true)
+      } UTC`
+      if (exists) {
+        this.metrics.withdrawalsValidated.inc()
+        this.logger.info(`valid withdrawal`, {
+          withdrawalHash: proofEvent.args.withdrawalHash,
+          provenAt,
+        })
+      } else {
+        this.logger.error(`withdrawalHash not seen on L2`, {
+          withdrawalHash: proofEvent.args.withdrawalHash,
+          provenAt,
+        })
+        this.state.forgeryDetected = true
+        this.metrics.isDetectingForgeries.set(1)
+        return
+      }
+    }
+
+    this.state.highestUncheckedBlockNumber = latestL1BlockNumber + 1
+
+    // If we got through the above without throwing an error, we should be fine to reset.
+    this.state.forgeryDetected = false
+    this.metrics.isDetectingForgeries.set(0)
+  }
+}
+
+if (require.main === module) {
+  const service = new WithdrawalMonitor()
+  service.run()
+}