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Array is duplicated on every refresh using ExpressJS and NodeJS

I have been trying to send the var logtraceArr = []; value to the browser using Expressjs but one first call empty array is displayed on 2nd call array is filled with first called function and on 3rd call array is appended with the same element.
I want the content to be displayed on the first.
var express = require("express");
var router = express.Router();
const fs = require("fs");
const path = require("path");
const readline = require('readline');
const directoryPath = path.resolve(__dirname,"../logtrace-filestore/edepoze-logs");
var logtraceArr = [];
router.get("/",function(req,res,next){
const fetchFileContentParsed = async (fileContentObj) => {
var logtraceObj = {
Direction : '',
FromServer: '',
ToServer:''
};
var pipearray = fileContentObj.toString().split("|");
for( i=0;i<pipearray.length;i++){
var Direction = new Array();
Direction = pipearray[5].split("::");
if (Direction.length == 2) {
logtraceObj.Direction = Direction[1];
} else {
logtraceObj.Direction = "";
}
}
logtraceArr.push(logtraceObj);
return {
logtraceArr
}
}
// Iterates all users and returns their Github info.
const getfileContent = async (files) => {
const fileContent = files.map((file) => {
const filePath = path.join(directoryPath,file);
//console.log("filePath ----->",filePath);
const readStream = fs.createReadStream(filePath);
const fileContent = readline.createInterface({
input: readStream
});
fileContent.on('line', function(line) {
const regExp = /\[Event([^]+\])/g
var matchedContent;
if ((matchedContent = line.match(regExp)) != null){
return fetchFileContentParsed(matchedContent) // Async function that fetches the user info.
.then((a) => {return a })
}
})
})
return Promise.all(fileContent) // Waiting for all the requests to get resolved.
}
function readFiles(dirname) {
//console.log(dirname);
fs.readdir(dirname, async function (err,filenames)
getfileContent(filenames).then((a) => {return a })
});
}
res.header("Access-Control-Allow-Origin", "*");
res.contentType('application/json');
//console.log(readFiles(directoryPath))
readFiles(directoryPath,logtraceArr);
res.send(logtraceArr);
});
module.exports = router;
i want the content to be loaded and print the array only once on refresh of the page

AMQJS0011E Invalid state not connected. AWS IoT core

I'm trying to have some sort of real-time dashboard that can subscribe to AWS IoT core topics and maybe publish too.
I have found a couple of items online, but I can't figure it out.
This is what I currently have:
function p4(){}
p4.sign = function(key, msg) {
const hash = CryptoJS.HmacSHA256(msg, key);
return hash.toString(CryptoJS.enc.Hex);
};
p4.sha256 = function(msg) {
const hash = CryptoJS.SHA256(msg);
return hash.toString(CryptoJS.enc.Hex);
};
p4.getSignatureKey = function(key, dateStamp, regionName, serviceName) {
const kDate = CryptoJS.HmacSHA256(dateStamp, 'AWS4' + key);
const kRegion = CryptoJS.HmacSHA256(regionName, kDate);
const kService = CryptoJS.HmacSHA256(serviceName, kRegion);
const kSigning = CryptoJS.HmacSHA256('aws4_request', kService);
return kSigning;
};
function getEndpoint() {
const REGION = "eu-west-1";
const IOT_ENDPOINT = "blablablabla-ats.iot.eu-west-1.amazonaws.com";
// your AWS access key ID
const KEY_ID = "My-key";
// your AWS secret access key
const SECRET_KEY = "my-access-token";
// date & time
const dt = (new Date()).toISOString().replace(/[^0-9]/g, "");
const ymd = dt.slice(0,8);
const fdt = `${ymd}T${dt.slice(8,14)}Z`
const scope = `${ymd}/${REGION}/iotdevicegateway/aws4_request`;
const ks = encodeURIComponent(`${KEY_ID}/${scope}`);
let qs = `X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=${ks}&X-Amz-Date=${fdt}&X-Amz-SignedHeaders=ho
const req = `GET\n/mqtt\n${qs}\nhost:${IOT_ENDPOINT}\n\nhost\n${p4.sha256('')}`;
qs += '&X-Amz-Signature=' + p4.sign(
p4.getSignatureKey( SECRET_KEY, ymd, REGION, 'iotdevicegateway'),
`AWS4-HMAC-SHA256\n${fdt}\n${scope}\n${p4.sha256(req)}`
);
return `wss://${IOT_ENDPOINT}/mqtt?${qs}`;
}
// gets MQTT client
function initClient() {
const clientId = Math.random().toString(36).substring(7);
const _client = new Paho.MQTT.Client(getEndpoint(), clientId);
// publish method added to simplify messaging
_client.publish = function(topic, payload) {
let payloadText = JSON.stringify(payload);
let message = new Paho.MQTT.Message(payloadText);
message.destinationName = topic;
message.qos = 0;
_client.send(message);
}
return _client;
}
function getClient(success) {
if (!success) success = ()=> console.log("connected");
const _client = initClient();
const connectOptions = {
useSSL: true,
timeout: 3,
mqttVersion: 4,
onSuccess: success
};
_client.connect(connectOptions);
return _client;
}
let client = {};
function init() {
client = getClient();
client.onMessageArrived = processMessage;
client.onConnectionLost = function(e) {
console.log(e);
}
}
function processMessage(message) {
let info = JSON.parse(message.payloadString);
const publishData = {
retailer: retailData,
order: info.order
};
client.publish("sc/delivery", publishData);
}
$(document).ready(() => {
init();
client.subscribe("sc/orders/");
});
I keep getting the same error; AMQJS0011E Invalid state not connected., but I do see in the requests pane of chrome that there is an connection or so... What am I doing wrong here?
I don't see any of the logs anyhow...

Why is the module export variable empty?

I'm new to nodejs.
Here is my .js file. I'm trying to expose audioData variable to other functions. audioData variable value is being empty outside the function. I see the value when I print inside the function. What could be wrong?
'use strict';
var asyncrequest = require('request');
var xml2js = require('xml2js');
var parseString = xml2js.parseString;
var audioData = [];
asyncrequest("http://example.com/feed", function(error, responsemeta, body) {
parseString(body, function(err, result){
var stories = result['rss']['channel'][0]['item'];
console.log("Total stories: " + stories.length);
stories.forEach(function(entry) {
var singleObj = {}
singleObj['title'] = entry['title'][0];
singleObj['value'] = entry['enclosure'][0].$.url;
audioData.push(singleObj);
});
});
console.dir(audioData);
});
module.exports = audioData;
console.log("Program ended");

You'll have to return a promise for the audioData, not the audioData itself! You can learn more about promises elsewhere. Happily there's a promisified version of request, request-promise, that you can use like so:
'use strict';
var rp = require('request-promise');
var xml2js = require('xml2js');
var parseString = xml2js.parseString;
var audioData = [];
var promiseForAudioData = rp('http://example.com/feed')
.then(body => {
parseString(body, function(err, result){
var stories = result['rss']['channel'][0]['item'];
console.log("Total stories: " + stories.length);
stories.forEach(function(entry) {
var singleObj = {}
singleObj['title'] = entry['title'][0];
singleObj['value'] = entry['enclosure'][0].$.url;
audioData.push(singleObj);
});
});
return audioData;
})
.catch(console.error.bind(console));
module.exports = promiseForAudioData;
console.log("Program ended");

If you don't want to use promises, you can either export inside the callback or export the request method itself.
asyncrequest("http://example.com/feed", function(error, responsemeta, body) {
parseString(body, function(err, result){
var stories = result['rss']['channel'][0]['item'];
console.log("Total stories: " + stories.length);
stories.forEach(function(entry) {
var singleObj = {}
singleObj['title'] = entry['title'][0];
singleObj['value'] = entry['enclosure'][0].$.url; audioData.push(singleObj);
});
module.exports = audioData;
});
});
// Or
exports.get = function (callback) {
return asyncrequest(/* ... */, callback);
}
// Other module
require("./module").get(function (audioData) {
/* Do something */
})

node.js webtorrent collect all files by magnet link

I have not used node.js before.
Have a .txt file with list of magnet links.
Want to write a json file with list of all files contained in these links.
var WebTorrent = require('webtorrent');
var fs = require('fs');
var client = new WebTorrent();
var array = fs.readFileSync('yop.txt').toString().split("\n");
i = 0;
while (i < array.length) {
//console.log(array[i]);
var magnetURI = array[i];
n = 0;
client.add(magnetURI, function (torrent) {
torrent.files.forEach(function (file) {
//console.log( file.name)
jsonString = JSON.stringify({'book': file.name});
fs.appendFile("data.json", jsonString, function (err) {
if (err) {console.log(err);} else { n++ }
});
if (n == torrent.files.length) {i++ }
})
})
}
when run gives the following error
Sorry for such a terrible code.

var WebTorrent = require('webtorrent')
var fs = require('fs')
var stream = fs.createWriteStream("2.txt");
var client = new WebTorrent()
var array = fs.readFileSync('yop.txt').toString().split("\n");
i = 0;
function parseMagnet (uri){
var magnetURI = uri[i]
console.log(magnetURI)
client.add(magnetURI, function (torrent) {
torrent.files.forEach(function (file) {
writeStr = (uri[i]+ '\n'+ file.name+ '\n');
stream.write(writeStr);
console.log(file.name)
});
console.log('Done !')
console.log(i)
i += 1
parseMagnet(array);
client.remove(magnetURI);
})
}
parseMagnet(array)

aws lambda function how to use responses to perform calculation

Trying to create a lambda function that lists tagged ec2 and tagged rds and performs an action thereafter. This is the first time i have used javascript and would appreciate some help.
Please see my example below
var aws = require('aws-sdk');
var ec2 = new aws.EC2();
var rds = new aws.RDS();
aws.config.region = 'us-east-1';
exports.handler = function(event,context) {
if (event) {
console.log(event.id);
}
//setup params for rds call
var rdsparams = {
DBInstanceIdentifier: 'master',
};
//setup params for ec2 call
var ec2params = {
Filters: [
{
Name: 'tag:role',
Values: [
'app'
],
}
]
};
//Get ec2 instances with app tag, may need to add a condition on running so pulled it into hash
ec2.describeInstances(ec2params, function(err, appdata) {
if (err) {
console.log(err);
return;
}
else {
var apparray={};
for(var i = 0; i < appdata.Reservations.length; i++) {
var ins = appdata.Reservations[i].Instances[0];
var id = ins.InstanceId;
var state = ins.State.Name;
apparray[id]=state;
}
console.log(apparray);
context.succeed(apparray);
}
});
rds.describeDBInstances(rdsparams, function(err, data) {
if (err) {
console.log(err, err.stack);
return;
}
else {
var rdsarray={};
var rdsarray=(data);
console.log(rdsarray);
var ins=rdsarray[0];
var name = ins.ReadReplicaDBInstanceIdentifiers[0];
rdsarray[replicant]=name;
}
context.succeed(rdsarray);
});
//context.done();
};
I want to return my filtered (apparray) and (rdsarray) back from my functions and perform a calculation on this within the main body of the script. Any ideas on how to do this.
something like
var replicas = rdsarray.length for example
Thanks in advance

var aws = require('aws-sdk');
var ec2 = new aws.EC2();
var rds = new aws.RDS();
aws.config.region = 'us-east-1';
exports.handler = function(event, context) {
if (event) {
console.log(event.id);
}
//setup params for rds call
var rdsparams = {
DBInstanceIdentifier: 'master',
};
//setup params for ec2 call
var ec2params = {
Filters: [{
Name: 'tag:role',
Values: [
'app'
],
}]
};
//Get ec2 instances with app tag, may need to add a condition on running so pulled it into hash
ec2.describeInstances(ec2params, function(err, appdata) {
if (err)
return context.done(err, null);
var apparray = {};
for (var i = 0; i < appdata.Reservations.length; i++) {
var ins = appdata.Reservations[i].Instances[0];
var id = ins.InstanceId;
var state = ins.State.Name;
apparray[id] = state;
}
console.log(apparray);
var resultData = {};
resultData.apparray = apparray;
rds.describeDBInstances(rdsparams, function(err, data) {
if (err)
return context.done(err, null);
var rdsarray = {};
var rdsarray = (data);
console.log(rdsarray);
var ins = rdsarray[0];
var name = ins.ReadReplicaDBInstanceIdentifiers[0];
rdsarray[replicant] = name;
resultData.rdsarray = rdsarray;
context.done(null, resultData);
});
});
};
and back in the code from you are calling the lambda function
var lambda = new sdk.Lambda();
var params = {
FunctionName: 'arn:aws:lambda:us-west-2:1541546477777:function:MyFunction',
Payload: JSON.stringify(/*your params here*/)
};
lambda.invoke(params, function(err, data) {
if (err) {
console.log('error ===', err);
return ;
}
var lambdaData = JSON.parse(data.Payload);
// do your stuff here
});
Is this what you needed? It may be broken but I hope you get the idea of it