feat: add pino for logging

.env.example

@@ -2,3 +2,4 @@ SEED="your sponsor wallet seed phrase"
 PASSWORD="sponsoredbyxverse"
 NUM_ADDRESSES=5
 MAX_FEE=50000
+LOG_LEVEL=debug

config/config.ts

@@ -29,4 +29,5 @@ export default {
   maxFee: isEnvVarValid(
     process.env.MAX_FEE as string
   ),
+  logLevel: process.env.LOG_LEVEL || "info",
 };

package.json

@@ -23,7 +23,9 @@
     "cors": "^2.8.5",
     "dotenv": "^10.0.0",
     "express": "^4.17.1",
-    "node-cache": "^5.1.2"
+    "node-cache": "^5.1.2",
+    "pino": "^8.14.1",
+    "pino-pretty": "^10.0.1"
   },
   "devDependencies": {
     "@types/cors": "^2.8.13",

src/index.ts

@@ -24,6 +24,7 @@ initializeSponsorWallet();
 
 app.use(json());
 app.use(cors());
+app.use(requestLogMiddleware);
 
 app.get('/', (_: Request, res: Response) => {
   res.send('Ok');
@@ -34,7 +35,7 @@ app.use(errorHandler);
 app.use(wrongRouteHandler);
 
 const server = app.listen(port, () => {
-  console.log(
+  logger.info(
     `Stacks Transaction Sponsor Web Service started and listening at http://localhost:${port} in ${app.get(
       'env',
     )} mode`,

src/logger.ts

@@ -0,0 +1,67 @@
+import { RequestHandler } from "express";
+import pino, { Logger } from "pino";
+import config from "../config/config";
+
+let requestId = 0;
+
+declare global {
+  // eslint-disable-next-line @typescript-eslint/no-namespace
+  namespace Express {
+    // We extend the Express Request interface here to add custom properties which we'll inject with middleware
+    interface Request {
+      logger: Logger;
+    }
+  }
+}
+
+/**
+ * Use this for logging anything not in a request context, otherwise, use req.logger
+ */
+export const logger = pino({
+  enabled: process.env.NODE_ENV !== "test",
+  level: config.logLevel,
+  transport: {
+    target: "pino-pretty",
+  },
+});
+
+export const requestLogMiddleware: RequestHandler = (req, res, next) => {
+  const requestLogger = logger.child({
+    requestId: requestId++,
+  });
+
+  req.logger = requestLogger;
+
+  try {
+    const onResponseComplete = () => {
+      res.removeListener("close", onResponseComplete);
+      res.removeListener("finish", onResponseComplete);
+      res.removeListener("error", onResponseComplete);
+
+      const logMethod = res.statusCode >= 400 ? "warn" : "info";
+
+      req.logger[logMethod](
+        {
+          statusCode: res.statusCode,
+          host: req.hostname,
+          path: req.path,
+          method: req.method,
+        },
+        "request completed"
+      );
+    };
+
+    res.on("close", onResponseComplete);
+    res.on("finish", onResponseComplete);
+    res.on("error", onResponseComplete);
+
+    requestLogger.info(
+      { host: req.hostname, path: req.path, method: req.method },
+      "request started"
+    );
+    next();
+  } catch (err) {
+    requestLogger.error({ err }, "error in request log middleware");
+    next(err);
+  }
+};

src/response.ts

@@ -7,10 +7,22 @@ export const errorHandler: ErrorRequestHandler = (err, req, res) => {
     message: err.message,
   });
 
+  req.logger.error({ err }, 'an error occurred');
+};
+
 export const wrongRouteHandler: RequestHandler = (req, res) => {
   const statusCode = 404;
+  const message = 'Route not found. Request failed with status code 404';
   res.status(statusCode).json({
     status: statusCode,
-    message: 'Route not found. Request failed with status code 404 ',
+    message,
   });
-}
+  req.logger.info({
+    message,
+    path: req.path,
+    params: req.params,
+    headers: req.headers,
+    body: req.body,
+    ip: req.ip,
+  });
+};