Merge remote-tracking branch 'syslog/master'

Merge cloudron-syslog code here

syslog/server.js

@@ -0,0 +1,61 @@
+'use strict';
+
+exports = module.exports = {
+    start,
+    stop
+};
+
+const LOG_FILENAME = 'app.log';
+
+const assert = require('assert'),
+    dgram = require('dgram'),
+    fs = require('fs'),
+    path = require('path'),
+    parser = require('nsyslog-parser');
+
+let server = null;
+
+function start(options, callback) {
+    assert.strictEqual(typeof options, 'object');
+    assert.strictEqual(typeof options.port, 'number');
+    assert.strictEqual(typeof options.logFolder, 'string');
+    assert.strictEqual(typeof callback, 'function');
+
+    server = dgram.createSocket('udp4');
+
+    server.on('error', function (error) {
+        callback(error);
+    }).on('listening', function () {
+        callback();
+    }).on('message', function (msg /*, rinfo */) {
+        const info = parser(msg.toString());
+
+        if (!info || !info.appName) return console.log('Ignore unknown app log:', msg.toString());
+
+        // remove line breaks to avoid holes in the log file
+        // we do not ignore empty log lines, to allow gaps for potential ease of readability
+        const message = info.message.replace(/\n/g, '');
+
+        const filePath = path.join(options.logFolder, info.appName);
+        const fileName = path.join(filePath, LOG_FILENAME);
+
+        try {
+            fs.mkdirSync(filePath, { recursive: true });
+            fs.appendFileSync(fileName, info.ts.toISOString() + ' ' + message + '\n');
+        } catch (error) {
+            console.error(error);
+        }
+    }).bind(options.port);
+}
+
+function stop(callback) {
+    assert.strictEqual(typeof callback, 'function');
+
+    if (!server) return callback();
+
+    server.close();
+
+    server = null;
+
+    callback();
+}