Basic redemptions monitoring (#678)

Refs: keep-network/keep-core#3664
Depends on: #677

This changeset adds redemptions to the monitoring system. Specifically,
two new system events are supported now:

### Redemption requested

An **informational system event** indicating that a new redemption was
requested from the on-chain Bridge contract. This event is directly sent
to Discord as a notification that does not require any action.

### Large redemption requested

A **warning system event** indicating that a large redemption was
requested from the on-chain Bridge contract. This event is sent to
Sentry hub and should get team’s attention. The default action is making
sure that the redemption is not a result of a malicious action, and if
not, that the redemption is handled correctly by the system.

monitoring/README.adoc

@@ -158,6 +158,8 @@ The behavior can be configured using the following env variables:
 
 |*LARGE_DEPOSIT_THRESHOLD_SAT* |Satoshi threshold used to determine which deposits are large. Default: _1000000000_ |No
 
+|*LARGE_REDEMPTION_THRESHOLD_SAT* |Satoshi threshold used to determine which redemptions are large. Default: _1000000000_ |No
+
 |*DATA_DIR_PATH* |Directory used to persist processing data. Default: _./data_ |No
 
 |*SENTRY_DSN* |DSN of the Sentry receiver. If not set, events are not dispatched to Sentry |No

monitoring/docs/monitoring-and-telemetry.adoc

@@ -111,11 +111,13 @@ are propagated to the Sentry hub that decides about next steps. Specific system
 events produced by the monitoring component are:
 
 * deposit revealed,
+* redemption requested,
 * wallet registered,
 * DKG result submitted,
 * DKG result approved,
 * DKG result challenged,
 * large deposit revealed,
+* large redemption requested,
 * optimistic minting canceled,
 * optimistic minting requested too early,
 * optimistic minting requested for undetermined Bitcoin transaction,
@@ -131,6 +133,12 @@ An *informational system event* indicating that a new deposit was revealed to
 the on-chain Bridge contract. This event is directly sent to Discord as a
 notification that does not require any action.
 
+==== Redemption requested
+
+An *informational system event* indicating that a new redemption was requested
+from the on-chain Bridge contract. This event is directly sent to Discord as a
+notification that does not require any action.
+
 ==== Wallet registered
 
 An *informational system event* indicating that a new wallet was registered
@@ -164,6 +172,14 @@ on-chain Bridge contract. This event is sent to Sentry hub and should get
 team’s attention. The default action is making sure that the deposit is
 handled correctly by the system.
 
+==== Large redemption requested
+
+A *warning system event* indicating that a large redemption was requested from
+the on-chain Bridge contract. This event is sent to Sentry hub and should get
+team’s attention. The default action is making sure that the redemption is
+not a result of a malicious action, and if not, that the redemption is
+handled correctly by the system.
+
 ==== Optimistic minting cancelled
 
 A *warning system event* indicating that an optimistic minting request was

monitoring/src/block-explorer.ts

@@ -0,0 +1,23 @@
+import { context, Environment } from "./context"
+
+import type { BitcoinTransactionHash, Hex } from "@keep-network/tbtc-v2.ts"
+
+const ethTxUrlPrefixMapping = {
+  [Environment.Mainnet]: "https://etherscan.io/tx",
+  [Environment.Testnet]: "https://goerli.etherscan.io/tx",
+}
+
+export function createEthTxUrl(txHash: Hex) {
+  return `${
+    ethTxUrlPrefixMapping[context.environment]
+  }/${txHash.toPrefixedString()}`
+}
+
+const btcTxUrlPrefixMapping = {
+  [Environment.Mainnet]: "https://mempool.space/tx",
+  [Environment.Testnet]: "https://mempool.space/testnet/tx",
+}
+
+export function createBtcTxUrl(txHash: BitcoinTransactionHash) {
+  return `${btcTxUrlPrefixMapping[context.environment]}/${txHash.toString()}`
+}

monitoring/src/context.ts

@@ -4,6 +4,7 @@ const {
   ETHEREUM_URL,
   ELECTRUM_URL,
   LARGE_DEPOSIT_THRESHOLD_SAT,
+  LARGE_REDEMPTION_THRESHOLD_SAT,
   DATA_DIR_PATH,
   SENTRY_DSN,
   DISCORD_WEBHOOK_URL,
@@ -52,6 +53,7 @@ export const context = {
   ethereumUrl: resolveEthereumUrl(),
   electrumUrl: resolveElectrumUrl(),
   largeDepositThresholdSat: LARGE_DEPOSIT_THRESHOLD_SAT ?? 1000000000, // 10 BTC by default
+  largeRedemptionThresholdSat: LARGE_REDEMPTION_THRESHOLD_SAT ?? 1000000000, // 10 BTC by default
   dataDirPath: DATA_DIR_PATH ?? "./data",
   sentryDsn: SENTRY_DSN,
   discordWebhookUrl: DISCORD_WEBHOOK_URL,

monitoring/src/deposit-monitor.ts

@@ -1,43 +1,21 @@
 import { BigNumber } from "ethers"
 
 import { SystemEventType } from "./system-event"
-import { context, Environment } from "./context"
+import { context } from "./context"
+import { createBtcTxUrl, createEthTxUrl } from "./block-explorer"
 
 import type { SystemEvent, Monitor as SystemEventMonitor } from "./system-event"
 import type { DepositRevealedEvent as DepositRevealedChainEvent } from "@keep-network/tbtc-v2.ts/dist/src/deposit"
 import type { Bridge } from "@keep-network/tbtc-v2.ts/dist/src/chain"
 
-const satsToRoundedBTC = (sats: BigNumber): string =>
+export const satsToRoundedBTC = (sats: BigNumber): string =>
   (sats.div(BigNumber.from(1e6)).toNumber() / 100).toFixed(2)
 
-const hashUrls = (chainEvent: DepositRevealedChainEvent) => {
-  let fundingHashUrlPrefix = ""
-  let revealHashUrlPrefix = ""
-  switch (context.environment) {
-    case Environment.Mainnet: {
-      fundingHashUrlPrefix = "https://mempool.space/tx/"
-      revealHashUrlPrefix = "https://etherscan.io/tx/"
-      break
-    }
-    case Environment.Testnet: {
-      fundingHashUrlPrefix = "https://mempool.space/testnet/tx/"
-      revealHashUrlPrefix = "https://goerli.etherscan.io/tx/"
-      break
-    }
-  }
-
-  const fundingHash = chainEvent.fundingTxHash.toString()
-  const transactionHash = chainEvent.transactionHash.toPrefixedString()
-  return {
-    btcFundingTxHashURL: fundingHashUrlPrefix + fundingHash,
-    ethRevealTxHashURL: revealHashUrlPrefix + transactionHash,
-  }
-}
-
 const DepositRevealed = (
   chainEvent: DepositRevealedChainEvent
 ): SystemEvent => {
-  const { btcFundingTxHashURL, ethRevealTxHashURL } = hashUrls(chainEvent)
+  const btcFundingTxHashURL = createBtcTxUrl(chainEvent.fundingTxHash)
+  const ethRevealTxHashURL = createEthTxUrl(chainEvent.transactionHash)
 
   return {
     title: "Deposit revealed",
@@ -57,7 +35,8 @@ const DepositRevealed = (
 const LargeDepositRevealed = (
   chainEvent: DepositRevealedChainEvent
 ): SystemEvent => {
-  const { btcFundingTxHashURL, ethRevealTxHashURL } = hashUrls(chainEvent)
+  const btcFundingTxHashURL = createBtcTxUrl(chainEvent.fundingTxHash)
+  const ethRevealTxHashURL = createEthTxUrl(chainEvent.transactionHash)
 
   return {
     title: "Large deposit revealed",

monitoring/src/index.ts

@@ -13,6 +13,7 @@ import { context } from "./context"
 import { MintingMonitor } from "./minting-monitor"
 import { WalletMonitor } from "./wallet-monitor"
 import { SupplyMonitor } from "./supply-monitor"
+import { RedemptionMonitor } from "./redemption-monitor"
 
 import type { Client as BitcoinClient } from "@keep-network/tbtc-v2.ts/dist/src/bitcoin"
 import type {
@@ -27,6 +28,7 @@ const monitors: SystemEventMonitor[] = [
   new MintingMonitor(contracts.bridge, contracts.tbtcVault, btcClient),
   new SupplyMonitor(contracts.tbtcToken, new SupplyMonitorFilePersistence()),
   new WalletMonitor(contracts.bridge),
+  new RedemptionMonitor(contracts.bridge),
 ]
 
 const receivers: SystemEventReceiver[] = ((): SystemEventReceiver[] => {

monitoring/src/redemption-monitor.ts

@@ -0,0 +1,88 @@
+import { BigNumber } from "ethers"
+
+import { context } from "./context"
+import { SystemEventType } from "./system-event"
+import { satsToRoundedBTC } from "./deposit-monitor"
+import { createEthTxUrl } from "./block-explorer"
+
+import type { RedemptionRequestedEvent as RedemptionRequestedChainEvent } from "@keep-network/tbtc-v2.ts/dist/src/redemption"
+import type { Bridge } from "@keep-network/tbtc-v2.ts/dist/src/chain"
+import type { Monitor as SystemEventMonitor, SystemEvent } from "./system-event"
+
+const RedemptionRequested = (
+  chainEvent: RedemptionRequestedChainEvent
+): SystemEvent => {
+  const ethRequestTxHashURL = createEthTxUrl(chainEvent.transactionHash)
+
+  return {
+    title: "Redemption requested",
+    type: SystemEventType.Informational,
+    data: {
+      walletPublicKeyHash: chainEvent.walletPublicKeyHash,
+      redeemerOutputScript: chainEvent.redeemerOutputScript,
+      requestedAmountBTC: satsToRoundedBTC(chainEvent.requestedAmount),
+      ethRequestTxHash: chainEvent.transactionHash.toPrefixedString(),
+      ethRequestTxHashURL,
+    },
+    block: chainEvent.blockNumber,
+  }
+}
+
+const LargeRedemptionRequested = (
+  chainEvent: RedemptionRequestedChainEvent
+): SystemEvent => {
+  const ethRequestTxHashURL = createEthTxUrl(chainEvent.transactionHash)
+
+  return {
+    title: "Large redemption requested",
+    type: SystemEventType.Warning,
+    data: {
+      walletPublicKeyHash: chainEvent.walletPublicKeyHash,
+      redeemerOutputScript: chainEvent.redeemerOutputScript,
+      requestedAmountBTC: satsToRoundedBTC(chainEvent.requestedAmount),
+      ethRequestTxHash: chainEvent.transactionHash.toPrefixedString(),
+      ethRequestTxHashURL,
+    },
+    block: chainEvent.blockNumber,
+  }
+}
+
+export class RedemptionMonitor implements SystemEventMonitor {
+  private bridge: Bridge
+
+  constructor(bridge: Bridge) {
+    this.bridge = bridge
+  }
+
+  async check(fromBlock: number, toBlock: number): Promise<SystemEvent[]> {
+    // eslint-disable-next-line no-console
+    console.log("running redemption monitor check")
+
+    const chainEvents = await this.bridge.getRedemptionRequestedEvents({
+      fromBlock,
+      toBlock,
+    })
+
+    const systemEvents: SystemEvent[] = []
+
+    // eslint-disable-next-line no-plusplus
+    for (let i = 0; i < chainEvents.length; i++) {
+      const chainEvent = chainEvents[i]
+
+      systemEvents.push(RedemptionRequested(chainEvent))
+
+      if (
+        chainEvent.requestedAmount.gt(
+          BigNumber.from(context.largeRedemptionThresholdSat)
+        )
+      ) {
+        systemEvents.push(LargeRedemptionRequested(chainEvent))
+      }
+    }
+
+    // eslint-disable-next-line no-console
+    console.log("completed redemption monitor check")
+
+    return systemEvents
+  }
+}