Make the NamedLevel logger a raw objectmode stream

README.md

@@ -147,6 +147,8 @@ logging:
   sampled_levels:
     'trace/webrequest': 0.2
   streams:
+  - type: stdout # log to stdout
+    named_levels: true # emit log level name instead of index. e.g. INFO vs 30
   # Use gelf-stream -> logstash
   - type: gelf
     host: logstash1003.eqiad.wmnet

lib/logger.js

 'use strict';
 
+const Writable = require('stream').Writable;
 const bunyan = require('bunyan');
 const gelfStream = require('gelf-stream');
 const syslogStream = require('bunyan-syslog-udp');
@@ -12,15 +13,23 @@ function extractSimpleLevel(levelPath) {
     return typeof levelPath === 'string' && levelPath.split('/')[0];
 }
 
-function NamedLevelStdout() {
-    return {
-        write: (entry) => {
-            // Kind of inefficient approach
-            var logObject = JSON.parse(entry);
-            logObject.level = bunyan.nameFromLevel[logObject.level].toUpperCase();
-            process.stdout.write(JSON.stringify(logObject) + '\n');
-        }
-    };
+class NamedLevelStdout extends Writable {
+    constructor(downstream, options = {}) {
+        super(Object.assign(options, { objectMode: true }));
+        this.downstream = downstream;
+    }
+    _write(logEntry, encoding, callback) {
+        logEntry.level = bunyan.nameFromLevel[logEntry.level].toUpperCase();
+        this.downstream.write(
+            JSON.stringify(logEntry) + '\n',
+            encoding,
+            callback
+        );
+    }
+    destroy() {
+        super.destroy();
+        this.downstream.destroy();
+    }
 }
 
 const streamConverter = {
@@ -52,16 +61,18 @@ const streamConverter = {
         };
     },
     stdout(stream, conf) {
-        return {
-            stream: process.stdout,
-            level: stream.level || conf.level
-        };
-    },
-    namedstdout(stream, conf) {
-        return {
-            stream: NamedLevelStdout(),
-            level: stream.level || conf.level
-        };
+        if ( stream.named_levels ) {
+            return {
+                type: 'raw',
+                stream: new NamedLevelStdout(process.stdout),
+                level: stream.level || conf.level
+            };
+        } else {
+            return {
+                stream: process.stdout,
+                level: stream.level || conf.level
+            };
+        }
     },
     debug(stream, conf) {
         try {