Implement connection-checking

src/main.js

@@ -14,6 +14,8 @@ const { RegexBlockStream } = require("./streamHandler/RegexBlockStream.js");
 const { PacketStreamFactory } = require("./streamHandler/PacketStreamFactory.js");
 const { PacketInfluxPointFactory } = require("./streamHandler/PacketInfluxPointFactory.js");
 const { InfluxPointWriter } = require("./streamHandler/InfluxPointWriter.js");
+const { InfluxDbLineProtocolWriter } = require("./streamHandler/InfluxDbLineProtocolWriter.js");
+const { InfluxPointToLineProtoStream } = require("./streamHandler/InfluxPointToLineProtoStream.js");
 
 const userHelper = require("./helper/userHelper.js");
 
@@ -25,18 +27,25 @@ const env = process.env;
     env.LOGLEVEL            ??= "INFO";
     env.WIFI_INTERFACE      ??= "wlan0";
     env.HOSTNAME            ??= Os.hostname();
+
+    env.USE_INFLUXDB_LINEPROTOCOL   ??= false;
 }
 // Required vars
-let errorMsg = requireEnvVars([
+let errorMsg = requireEnvVars(
+    env.USE_INFLUXDB_LINEPROTOCOL? [    // When lineprotocol is enabled, we need host and port
+        "INFLUXDB_LINEPROTOCOL_HOST", "INFLUXDB_LINEPROTOCOL_PORT",
+    ] : [       // When its disabled, influxdb-data
         "INFLUX_URL", "INFLUX_TOKEN",
         "INFLUX_ORG", "INFLUX_BUCKET"
-]);
+    ]);
 if(errorMsg){
     logger.fatal(errorMsg);
     exit(1);
 }
 
 (async function() {
+    let pointWriter;
+    if(!env.USE_INFLUXDB_LINEPROTOCOL){
         logger.info("Setup Influx..");
         const influxDb = new InfluxDB({url: env.INFLUX_URL, token: env.INFLUX_TOKEN});
 
@@ -61,7 +70,46 @@ if(errorMsg){
         logger.debug("Get WriteApi & set default-hostname to", `'${env.HOSTNAME}'`);
         const influxWriteApi = influxDb.getWriteApi(env.INFLUX_ORG, env.INFLUX_BUCKET, "us");
         //influxWriteApi.useDefaultTags({"hostname": env.HOSTNAME});
+
+        pointWriter = new InfluxPointWriter(influxWriteApi);
+
         logger.info("Influx ok");
+    }
+    else {
+        logger.info("Setup Influxdb-LineProtocol..");
+
+        let lineProtocolWriter = new InfluxDbLineProtocolWriter(env.INFLUXDB_LINEPROTOCOL_HOST, env.INFLUXDB_LINEPROTOCOL_PORT);
+
+        logger.debug("Create PointToLineProto and pipe to LineProtocolWriter");
+        pointWriter = new InfluxPointToLineProtoStream();
+        pointWriter
+            .setEncoding("utf8")
+            .pipe(lineProtocolWriter);
+        
+        logger.debug("Waiting for connection..");
+        await new Promise((resolve, reject) => {
+            lineProtocolWriter.once("connect", () => {
+                resolve();
+            });
+            lineProtocolWriter.once("error", (err) => {
+                reject(err);
+            });
+            setTimeout(() => {  // After timeout, reject promise
+                reject("Timeout whilst waiting to connect");
+            }, 6500);
+        })
+            .then(() => {
+                logger.info("Influxdb-LineProtocol ok");
+            })
+            .catch((err) => {
+                if(err) {
+                    logger.error("Error whilst checking Influxdb-LineProtocol:");
+                    logger.error(err);
+                }
+                logger.fatal("Setup Influxdb-LineProtocol failed!");
+                exit(1);
+            });
+    }
 
     logger.info("Starting tcpdump..");
     const TCPDUMP_BASECMD = "tcpdump -vvv -e -n -X -s0 -i";
@@ -72,13 +120,12 @@ if(errorMsg){
     let regexBlockStream = new RegexBlockStream(/^\d{2}:\d{2}:\d{2}.\d{6}.*(\n( {4,8}|\t\t?).*)+\n/gm);
     let packetStreamFactory = new PacketStreamFactory();
     let packetInfluxPointFactory = new PacketInfluxPointFactory();
-    let influxPointWriter = new InfluxPointWriter(influxWriteApi);
     proc.stdout
         .setEncoding("utf8")
         .pipe(regexBlockStream)
         .pipe(packetStreamFactory)
         .pipe(packetInfluxPointFactory)
-        .pipe(influxPointWriter);
+        .pipe(pointWriter);
 
     logger.debug("Attaching error-logger..");
     const loggerTcpdump = logFactory("tcpdump");

src/streamHandler/InfluxDbLineProtocolWriter.js

@@ -0,0 +1,72 @@
+const logger = require.main.require("./helper/logger.js")("InfluxDbLineProtocolWriter");
+const net = require("net");
+
+/**
+ * Get points and write them into influx
+ */
+class InfluxDbLineProtocolWriter extends net.Socket{
+    /**
+     * 
+     * @param {string} host Host of line-server
+     * @param {string} port Port of line-server
+     * @param {object} options Options for further configuration
+     */
+    constructor(host, port, options = {}) {
+        super();
+
+        this._host = host;
+        this._port = port;
+
+        // options defaults
+        options.autoConnect     ??= true;
+        options.timeout         ??= 5000;
+        options.autoReconnect   ??= true;
+        options.autoReconnectBackoffTime    ??= 3000;
+        this._options = options;
+
+        this._isConnected = false;
+
+        super.setKeepAlive(true, 5000);
+
+        // Register auto-Reconnect if enabled
+        if(this._options.autoReconnect){
+            this.on("connect", () => {
+                logger.debug("Connection established!");
+                this._isConnected = true;
+
+                if(this._autoReconnectTimeout)
+                    clearInterval(this._autoReconnectTimeout);
+                this._autoReconnectTimeout = 0;
+            });
+
+            this.on("error", (err) => {
+                logger.error(err.code, "TCP ERROR");
+                this._isConnected = false;
+                
+                if(!this._autoReconnectTimeout)
+                    this._autoReconnectTimeout = setInterval(() => {
+                        this.connect();
+                    },
+                    this._options.autoReconnectBackoffTime);
+            });
+        }
+
+        // Autoconnect if requested
+        if(this._options.autoConnect) this.connect();
+    }
+
+    get host(){ return this._host; }
+    get port(){ return this._port; }
+
+    get isConnected(){ return this._isConnected; }
+
+    connect(){
+        logger.debug("Connecting..");
+        super.connect(this._port, this._host);
+    }
+}
+
+// Specify exports
+module.exports = {
+    InfluxDbLineProtocolWriter
+};

src/streamHandler/InfluxPointToLineProtoStream.js

@@ -0,0 +1,22 @@
+const logger = require.main.require("./helper/logger.js")("InfluxPointToLineProtoStream");
+const { Transform } = require("stream");
+
+/**
+ * Get points and converts them to Line-protocol
+ */
+class InfluxPointToLineProtoStream extends Transform{
+    constructor(){
+        super({
+            writableObjectMode: true
+        });
+    }
+
+    _transform(point, encoding, next){
+        next(null, point.toLineProtocol() +"\n");
+    }
+}
+
+// Specify exports
+module.exports = {
+    InfluxPointToLineProtoStream
+};