Add googleCloudLog, improve logging of info; alert on failed liquidat…

…ion (compound-finance#619)

* Add googleCloudLog, improve logging of info; alert on failed liquidation

* lint

* log useFlashbots

scripts/liquidation_bot/googleCloudLog.ts

@@ -0,0 +1,20 @@
+/*
+Utility to log data in a structured way that will be reflected in Google Cloud
+Platform logs.
+
+Basically, lets you specify a severity level so we can do things like filtering
+and alerting in GCP.
+
+https://cloud.google.com/logging/docs/reference/v2/rest/v2/LogEntry#LogSeverity
+*/
+
+export enum LogSeverity {
+  INFO = 'INFO',       // Routine information, such as ongoing status or performance
+  WARNING = 'WARNING', // Warning events, things that might cause problems
+  ERROR = 'ERROR',     // Error events, things that are likely to cause problems
+  ALERT = 'ALERT'      // A person must take an action immediately; may cause someone to be alerted
+}
+
+export default function googleCloudLog(severity: LogSeverity, message: string) {
+  console.log(JSON.stringify({ severity, message }));
+}

scripts/liquidation_bot/index.ts

@@ -12,6 +12,7 @@ import {
 } from './liquidateUnderwaterBorrowers';
 import { FlashbotsBundleProvider } from '@flashbots/ethers-provider-bundle';
 import { providers, Wallet } from 'ethers';
+import googleCloudLog, { LogSeverity } from './googleCloudLog';
 
 const loopDelay = 5000;
 const loopsUntilUpdateAssets = 1000;
@@ -28,6 +29,11 @@ async function main() {
 
   const network = hre.network.name;
 
+  googleCloudLog(
+    LogSeverity.INFO,
+    `Liquidation Bot started ${JSON.stringify({network, deployment, liquidatorAddress, useFlashbots})}`
+  );
+
   const dm = new DeploymentManager(
     network,
     deployment,
@@ -85,14 +91,14 @@ async function main() {
   let loops = 0;
   while (true) {
     if (loops >= loopsUntilUpdateAssets) {
-      console.log('Updating assets');
+      googleCloudLog(LogSeverity.INFO, 'Updating assets');
       assets = await getAssets(comet);
       loops = 0;
     }
 
     const currentBlockNumber = await hre.ethers.provider.getBlockNumber();
 
-    console.log(`currentBlockNumber: ${currentBlockNumber}`);
+    googleCloudLog(LogSeverity.INFO, `currentBlockNumber: ${currentBlockNumber}`);
 
     if (currentBlockNumber !== lastBlockNumber) {
       lastBlockNumber = currentBlockNumber;
@@ -110,7 +116,7 @@ async function main() {
         );
       }
     } else {
-      console.log(`block already checked; waiting ${loopDelay}ms`);
+      googleCloudLog(LogSeverity.INFO, `block already checked; waiting ${loopDelay}ms`);
       await new Promise(resolve => setTimeout(resolve, loopDelay));
     }
 

scripts/liquidation_bot/liquidateUnderwaterBorrowers.ts

@@ -6,6 +6,7 @@ import {
 import { exp } from '../../test/helpers';
 import { FlashbotsBundleProvider } from '@flashbots/ethers-provider-bundle';
 import { PopulatedTransaction } from 'ethers';
+import googleCloudLog, { LogSeverity } from './googleCloudLog';
 
 export interface SignerWithFlashbots {
   signer: SignerWithAddress;
@@ -39,10 +40,10 @@ async function sendTxn(
   signerWithFlashbots: SignerWithFlashbots
 ) {
   if (signerWithFlashbots.flashbotsProvider) {
-    console.log('Sending a private txn');
+    googleCloudLog(LogSeverity.INFO, 'Sending a private txn');
     await sendFlashbotsPrivateTransaction(txn, signerWithFlashbots.flashbotsProvider);
   } else {
-    console.log('Sending a public txn');
+    googleCloudLog(LogSeverity.INFO, 'Sending a public txn');
     await signerWithFlashbots.signer.sendTransaction(txn);
   }
 }
@@ -53,16 +54,19 @@ async function attemptLiquidation(
   signerWithFlashbots: SignerWithFlashbots
 ) {
   try {
+    googleCloudLog(LogSeverity.INFO, `Attempting to liquidate ${targetAddresses} via ${liquidator.address}`);
     const txn = await liquidator.populateTransaction.initFlash({
       accounts: targetAddresses,
       pairToken: daiPool.tokenAddress,
       poolFee: daiPool.poolFee
     });
     await sendTxn(txn, signerWithFlashbots);
-    console.log(`Successfully liquidated ${targetAddresses}`);
+    googleCloudLog(LogSeverity.INFO, `Successfully liquidated ${targetAddresses} via ${liquidator.address}`);
   } catch (e) {
-    console.log(`Failed to liquidate ${targetAddresses}`);
-    console.log(e.message);
+    googleCloudLog(
+      LogSeverity.ALERT,
+      `Failed to liquidate ${targetAddresses} via ${liquidator.address}: ${e.message}`
+    );
   }
 }
 
@@ -92,13 +96,13 @@ export async function liquidateUnderwaterBorrowers(
 ): Promise<boolean> {
   const uniqueAddresses = await getUniqueAddresses(comet);
 
-  console.log(`${uniqueAddresses.size} unique addresses found`);
+  googleCloudLog(LogSeverity.INFO, `${uniqueAddresses.size} unique addresses found`);
 
   let liquidationAttempted = false;
   for (const address of uniqueAddresses) {
     const isLiquidatable = await comet.isLiquidatable(address);
 
-    console.log(`${address} isLiquidatable=${isLiquidatable}`);
+    googleCloudLog(LogSeverity.INFO, `${address} isLiquidatable=${isLiquidatable}`);
 
     if (isLiquidatable) {
       await attemptLiquidation(
@@ -118,10 +122,10 @@ export async function arbitragePurchaseableCollateral(
   assets: Asset[],
   signerWithFlashbots: SignerWithFlashbots
 ) {
-  console.log(`Checking for purchaseable collateral`);
+  googleCloudLog(LogSeverity.INFO, `Checking for purchaseable collateral`);
 
   if (await hasPurchaseableCollateral(comet, assets)) {
-    console.log(`There is purchaseable collateral`);
+    googleCloudLog(LogSeverity.INFO, `There is purchaseable collateral`);
     await attemptLiquidation(
       liquidator,
       [], // empty list means we will only buy collateral and not absorb