Adapt JSON output to the standard structure

lib/utils/common-headers.js

@@ -39,8 +39,7 @@ module.exports = function setCommonHeaders (req, res, callback) {
 
     getStatTag({ res }, (err, statTag) => {
         if (err) {
-            err.message = `Error generating Stat Tag header: ${err.message}`;
-            logger.warn({ error: err });
+            logger.warn({ error: err }, 'Error generating Stat Tag header');
         }
 
         if (statTag) {
@@ -100,8 +99,7 @@ function getTemplateHash ({ res }) {
         try {
             templateHash = res.locals.mapConfigProvider.getTemplateHash().substring(0, 8);
         } catch (err) {
-            err.message = `Error generating Stat Tag header: ${err.message}`;
-            logger.warn({ error: err });
+            logger.warn({ error: err }, 'Error generating Stat Tag header');
         }
 
         return templateHash;

lib/utils/logger.js

@@ -15,10 +15,21 @@ module.exports = class Logger {
         const options = {
             base: null, // Do not bind hostname, pid and friends by default
             level: LOG_LEVEL || logLevelFromNodeEnv,
+            formatters: {
+                level (label) {
+                    if (label === 'warn') {
+                        return { level: 'warning' };
+                    }
+
+                    return { level: label };
+                }
+            },
+            messageKey: 'message',
+            timestamp: () => `,"timestamp":"${new Date(Date.now()).toISOString()}"`,
             serializers: {
-                request: requestSerializer,
-                response: responseSerializer,
-                error: (error) => Array.isArray(error) ? error.map((err) => errorSerializer(err)) : [errorSerializer(error)]
+                client_request: requestSerializer,
+                server_response: responseSerializer,
+                error: errorSerializer
             }
         };
         const dest = pino.destination({ sync: false }); // stdout