chore: fix the timestamp in instana logger from epoch time to ISO string

Author: abhilash-sivan

packages/collector/src/logger.js

@@ -95,7 +95,9 @@ exports.init = function init(userConfig = {}) {
     parentLogger = uninstrumentedLogger({
       name: '@instana/collector',
       level: 'info',
-      base: { threadId, pid: process.pid, hostname: os.hostname() }
+      base: { threadId, pid: process.pid, hostname: os.hostname() },
+      // Set ISO timestamp format for the default logger
+      timestamp: () => `,"time":"${new Date().toISOString()}"`
     });
   }
 
@@ -133,12 +135,17 @@ exports.init = function init(userConfig = {}) {
 
       // CASE: We copy any settings from the pino instance such as custom formats.
       if (symbols && Array.isArray(symbols)) {
+        // If there's a custom timestamp function from the userConfig logger  , we'll respect that
         const timeSym = symbols.find(sym => String(sym) === 'Symbol(pino.time)');
         // @ts-ignore
         const timestampFn = instance[timeSym];
 
-        if (timestampFn) {
+        // Only use the user's timestamp function if it's from a user-provided logger
+        if (timestampFn && userConfig.logger) {
           pinoOpts.timestamp = timestampFn;
+        } else if (!pinoOpts.timestamp) {
+          // If no timestamp function is set yet, fallback to ISO format
+          pinoOpts.timestamp = () => `,"time":"${new Date().toISOString()}"`;
         }
 
         const formattersSym = symbols.find(sym => String(sym) === 'Symbol(pino.formatters)');

packages/collector/test/logger_test.js

@@ -139,6 +139,32 @@ describe('logger', () => {
       stream => expect(stream.level).to.equal('info')
     );
   });
+
+  it('should use ISO timestamp format for pino logger', () => {
+    const logger = log.init({});
+
+    // Create a mock write stream to capture the log output
+    const capturedLogs = [];
+    const mockStream = {
+      write: function (chunk) {
+        capturedLogs.push(JSON.parse(chunk));
+      }
+    };
+
+    // Replace the stream temporarily
+    const originalStream = logger.logger[uninstrumentedLogger.symbols.streamSym];
+    logger.logger[uninstrumentedLogger.symbols.streamSym] = mockStream;
+
+    logger.info('Test log message');
+
+    // Restore the original stream
+    logger.logger[uninstrumentedLogger.symbols.streamSym] = originalStream;
+
+    // Verify the timestamp format in the captured log
+    expect(capturedLogs.length).to.equal(1);
+    expect(capturedLogs[0]).to.have.property('time');
+    expect(capturedLogs[0].time).to.match(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z$/);
+  });
 });
 
 /**