fix: update healthchek response

Author: doomsower

src/services/Client.ts

@@ -97,7 +97,7 @@ export default class Client {
   @Logger("Client")
   public logger!: ILogger;
 
-  #balance?: bigint;
+  #balance?: {value: bigint; status: string };
 
   #anvilInfo: AnvilNodeInfo | null = null;
 
@@ -297,7 +297,10 @@ export default class Client {
 
   async #checkBalance(): Promise<void> {
     const balance = await this.pub.getBalance({ address: this.address });
-    this.#balance = balance;
+    this.#balance = {
+      value: balance,
+      status: balance < this.config.minBalance ? "alert" : "healthy",
+    };
     this.logger.debug(`liquidator balance is ${formatEther(balance)}`);
     if (balance < this.config.minBalance) {
       this.notifier.alert(
@@ -357,7 +360,7 @@ export default class Client {
     return this.wallet.account.address;
   }
 
-  public get balance(): bigint | undefined {
+  public get balance(): { value: bigint; status: string } | undefined {
     return this.#balance;
   }
 

src/services/HealthCheckerService.ts

@@ -43,17 +43,7 @@ export default class HealthCheckerService {
       if (req.url === "/") {
         res.writeHead(200, { "Content-Type": "application/json" });
         res.end(
-          json_stringify({
-            startTime: this.#start,
-            version,
-            network: this.config.network,
-            family: "liquidators",
-            liquidationMode: this.config.liquidationMode,
-            address: this.client.address,
-            balance: this.client.balance,
-            currentBlock: this.scanner.lastUpdated,
-            timestamp: Number(this.scanner.lastTimestamp),
-          }),
+          json_stringify(this.#healthStatus),
         );
       } else if (req.url === "/metrics") {
         try {
@@ -86,6 +76,30 @@ export default class HealthCheckerService {
     this.log.info("launched");
   }
 
+  get #healthStatus() {
+    const balanceOk = !this.client.balance || this.client.balance.status === "healthy";
+    const now = Math.ceil(Date.now() / 1000)
+    const timestamp = Number(this.scanner.lastTimestamp);
+    const timestampOk = now - timestamp <= 120;
+    const status = (balanceOk && timestampOk) ? "healthy" : "alert";
+
+    return {
+      status,
+      startTime: this.#start,
+      version,
+      network: this.config.network,
+      family: "liquidators",
+      liquidationMode: this.config.liquidationMode,
+      address: this.client.address,
+      balance: this.client.balance,
+      currentBlock: this.scanner.lastUpdated,
+      timestamp: {
+        value: timestamp,
+        status: timestampOk ? "healthy" : "alert",
+      }
+    }
+  }
+
   /**
    * Returns metrics in prometheus format
    * https://prometheus.io/docs/concepts/data_model/