complete #1: add expression based message filter / templating for customized messages

Config.example.js

@@ -4,8 +4,8 @@ class Config {
             'test.txt',
             'test1.txt'
         ];
-        this.defaultMessageTemplateFilter = /^\[((\d{1,2}\/\w{3}\/\d{4}):(\d{2}:\d{2}:\d{2}) ([+-]\d{4}))\] status:(\d{3}) request_time:(\d{1,}.\d{3}) upstream_response_time:(\d{1,}.\d{3}) bytes_sent:(\d{1,}) client_ip:(\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b|(:{0,2}[\da-f]{1,4}){1,8}) domain:([\w.-]*) request:"((\w{3,7}) (\/[\w-.,_~:<>\\/[\]%@!$'()*+;?=&#]*) HTTP\/(\d\.\d))" referer:"([\w-.,_~:<>\\/[\]%@!$'()*+;?=&#]*)" user_agent:"([\w-.,_~: \/[\]%@!$'()*+;?=&#]*)"$/g
-        this.defaultMessageTemplateFilterMatchingGroupNames = {
+        this.defaultMessageTemplateFilter = /^\[((\d{1,2}\/\w{3}\/\d{4}):(\d{2}:\d{2}:\d{2}) ([+-]\d{4}))\] status:(\d{3}) request_time:(\d{1,}.\d{3}) upstream_response_time:(\d{1,}.\d{3}) bytes_sent:(\d{1,}) client_ip:(\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b|(:{0,2}[\da-f]{1,4}){1,8}) domain:([\w.-]*) request:"((\w{3,7}) (\/[\w-.,_~:<>\\/[\]%@!$'()*+;?=&#]*) HTTP\/(\d\.\d))" referer:"([\w-.,_~:<>\\/[\]%@!$'()*+;?=&#]*)" user_agent:"([\w-.,_~: \/[\]%@!$'()*+;?=&#]*)"$/;
+        this.defaultMatchingGroupName = {
             All: 0,
             DateTime: 1,
             Date: 2,
@@ -26,11 +26,16 @@ class Config {
         };
         this.expressions = [
             {
-                match: /HTTP\/\d\.\d\" 404/g,
-                subject: 'HTTP 404: ',
-                //messageTemplateFilter: /()/g
+                match: /status:404/,
+                //filter: (/** @type {string} */ line) => { return line.match(/./); },
+                subject: (/** @type {any} */ match) => {
+                    return `HTTP ${match[this.defaultMatchingGroupName.StatusCode]}: `;
+                },
+                template: (/** @type {any} */ match) => {
+                    return `${match[this.defaultMatchingGroupName.Domain]} \`"${match[this.defaultMatchingGroupName.Request]}"\``;
+                }
             },
-            { match: /HTTP\/\d\.\d\" 5\d{2}/g, subject: 'HTTP 5xx: ' }
+            { match: /status:5\d{2}/, subject: 'HTTP 5xx: ' }
         ];
 
         this.enableEmail = false;

Index.js

@@ -9,7 +9,6 @@ const Slack = require('slack-node');
 let transporter;
 let slack = new Slack();
 let mailOptions = {};
-let lineCounter = 0;
 const fileWatchers = {};
 let messages = new Array();
 let queueWorkerRunning = false;
@@ -26,12 +25,31 @@ async function notificationQueueWorker() {
             continue;
         }
 
+        let filterExpression = config.defaultMessageTemplateFilter;
+        if (message.expression.filter) {
+            filterExpression = message.expression.filter;
+        }
+        let match = message.message.match(filterExpression);
+
+        if (match === null) match = message.message;
+
+        const oldSubject = message.expression.subject;
+        if (typeof (message.expression.subject) !== 'function') {
+            var oldSubjectValue = message.expression.subject.toString();
+            message.expression.subject = () => oldSubjectValue;
+        }
+
+        const oldTemplate = message.expression.template;
+        if (typeof (message.expression.template) !== 'function') {
+            message.expression.template = () => `\`${message.message}\``;
+        }
+
         if (config.enableEmail) {
             await sendMail({
                 from: config.mailfrom,
                 to: config.mailto,
-                subject: `${config.subjectPrefix}`,
-                text: `${message.expression.subject}${message.message}`
+                subject: `${config.subjectPrefix}${message.expression.subject(match)}`,
+                text: message.expression.template(match)
             });
         }
 
@@ -39,12 +57,14 @@ async function notificationQueueWorker() {
             slack.webhook({
                 channel: config.slackChannel,
                 username: config.slackUserName,
-                text: `${message.expression.subject}${message.message}`
+                text: `${message.expression.subject(match)}${message.expression.template(match)}`
             }, (err, response) => {
                 if (config.debug && err) console.log(err, response);
             });
         }
 
+        message.expression.subject = oldSubjectValue;
+        message.expression.template = oldTemplate;
         await sleep(1000);
     }
 
@@ -57,7 +77,6 @@ async function filterLog( /** @type {string} */ line) {
         expression.match.lastIndex = 0;
 
         if (expression.match.test(line)) {
-            config.expressions[index].matchCounter++;
             messages.push({
                 expression: expression,
                 message: line
@@ -86,11 +105,6 @@ async function setupTail( /** @type {string[]} */ filesToWatch) {
         process.exit(1);
     }
 
-    for (let index = 0; index < config.expressions.length; index++) {
-        config.expressions[index].matchCounter = 0;
-        config.expressions[index].lastMatchContent = '';
-    }
-
     for (const fileName of filesToWatch) {
         if (!(await fs.exists(fileName))) {
             console.log(`File not found, not watching: ${fileName}`);
@@ -105,7 +119,6 @@ async function setupTail( /** @type {string[]} */ filesToWatch) {
         });
 
         tail.on('line', ( /** @type {string} */ data) => {
-            lineCounter++;
             filterLog(data);
         });