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how to check the aws s3 url is valid or not

I need to check the AWS s3 URL is valid or not using Nodejs, I need only the status code not all the data of the file
exa:-https://test.s3.us-east-2.amazonaws.com/occupancy.csv, I applied request method but it takes all the data from the file..second method AWS s3.headObject but it only checks the bucket name exist or not
tell me is there any method who give the status code that this URL has existed or not

You can simply do an HTTP head request to check whether the url exist.
var request = require("request");
var options = {
method: 'HEAD',
url: 'https://test.s3.us-east-2.amazonaws.com/occupancy.csv',
};
request(options, function (error, response, body) {
if (error) throw new Error(error);
console.log(response.statusCode);
});
Reference:
Getting HTTP headers with node.js

how to call webapi at server startup in NodeJS

I have created a get web api that i want to hit at my server startup for some specific task. I have used this method
var request = require('request');
request('http://localhost:3000/api/jobs/asd', function (error, response, body) {
if (!error && response.statusCode == 200) {
console.log(body) // Print the google web page.
}
}
)
But i am getting status code as 403. So i am not able to access my API at serve startup. Please suggest me the proper solution for the same.
thanks in adv.

You can place your code inside http callback like so :
http.createServer(app).listen(3000, () => {
//your code here
});

Detecting a 301 redirect or 404 in JSDom

I'm using JSDom to scrape pages and check page existence on bunch of S3 buckets. My buckets redirect to an page on 404 that then redirects to my site's main page. While trying to load a totally non-existent domain yields a ENOTFOUND error, the errors object is empty if I get a 404.
Using JSDom, how do I detect a redirect or a 404?

You could use request and get the statusCode. them pass the HTML fragment to JSDOM like so:
var jsdom = require("jsdom");
var request = require('request');
request(url, function (err, response, body) {
if (!err && response.statusCode == 200) {
jsdom.env({
html:body,
scripts: ["http://code.jquery.com/jquery.js"],
done: JS_DOM_FUNCTION()
});
}
else{
//You can handle any other status here
}
});

GET request in javascript to NodeJS

I'm trying to do a simple conection (request - response) from the javascript code on a web to a server in Node.js.
I have tried to make the request as follows:
var request = new XMLHttpRequest();
request.open('GET', 'http://localhost:4444/', false);
request.send();
if (request.status === 200) {
console.log(request.responseText);
}
Running this code I got an error in FireBug
I have continued searching and I found that this method is only to make GET requests on the same domain. To make cross domain requests we must use other strategies.
I found a jQuery method, and it seems that i'm on the right way:
$.get(
'http://localhost:4444/',
function(data) {
alert("sucess");
//Do anything with "data"
}
);
In this case I get the same response without the error.
It seems it works but the "alert" message is never shown! What happens? What am I doing wrong?
The Node.js server code is:
var http = require("http");
http.createServer(function(request, response) {
response.writeHead(200, {"Content-Type": "text/html"});
response.write("Response");
response.end();
}).listen(4444);

So you're running into cross domain issues. You have a few options:
1) since you're using node, use socket.io . It's cross domain compliant.
On the client:
<script src="Full path to were socket IO is held on your server//socket.io.js"></script>
<script>
var socket = io.connect();
socket.on('some_callback', function(data){
// receive data
});
socket.emit('some_other_callback', {'data': value}); //send data
</script>
Server:
var io = require('socket.io').listen(server);
// define interactions with client
io.sockets.on('connection', function(socket){
//send data to client
socket.emit('some_callback', {'data': value});
//recieve client data
socket.on('some_other_callback', function(data){
//do something
});
});
2) Since you just want to use GET you can use JSONP
$.getJSON('url_to_your_domain.com/?callback=?&other_data=something,
function(data){
//do something
}
);
Here we pass your normal GET params as well as callback=?. You will return the following from your server:
require('url');
var r = url.parse(req.url,true);
r.query.callback + '(' + some JSON + ')'
3) If you don't care about all browser compatibility you can use CORS:
You can see a much better example than I would be able to write Here

Cross domain ajax requires special support from your server.
Either CORS: http://en.wikipedia.org/wiki/Cross-origin_resource_sharing
Which not all browsers support yet. It involves special headers in both the request and response that tell the browser that one domain is allowed to communicate with the other, and for what data.
Or JSONP: http://en.wikipedia.org/wiki/JSONP
WHich will work anywhere, but has some implementation limitations. It involves the server wrapping the response in a javascript function callback that will execute and pass in that data you want.
Either way, the server needs to be setup for each of these approaches.

I think your problem is Same Origin Policy. Your browser must get webpage from node.js instance.
Otherwise, you must use something like CORS. There also good question on SO: Ways to circumvent the same-origin policy.

Cross-domain jQuery.getJSON from a Node.JS (using express) server does not work in Internet Explorer

This is an annoying problem, and I don't suppose that it's only IE that has this problem. Basically I have a Node.js server, from which I am making cross-domain calls to get some JSON data for display.
This needs to be a JSONP call and I give a callback in the URL. What I am not sure is, how to do this?
So the website (domainA.com) has an HTML page with a JS script like this (all works fine in Firefox 3):
<script type="text/javascript">
var jsonName = 'ABC'
var url = 'http://domainB.com:8080/stream/aires/' //The JSON data to get
jQuery.getJSON(url+jsonName, function(json){
// parse the JSON data
var data = [], header, comment = /^#/, x;
jQuery.each(json.RESULT.ROWS,function(i,tweet){ ..... }
}
......
</script>
Now my Node.js server is very simple (I'm using express):
var app = require('express').createServer();
var express = require('express');
app.listen(3000);
app.get('/stream/aires/:id', function(req, res){
request('http://'+options.host+':'+options.port+options.path, function (error, response, body) {
if (!error && response.statusCode == 200) {
console.log(body); // Print the google web page.
res.writeHead(200, {
'Content-Type': 'application/json',
'Cache-Control': 'no-cache',
'Connection': 'keep-alive',
'Access-Control-Allow-Origin': '*',
'Access-Control-Allow-Credentials': 'true'
});
res.end(JSON.stringify(JSON.parse(body)));
}
})
});
How can I change these two so they will work with cross-domain GET in IE? I have been searching the internet and there seem to be a few different things like jQuery.support.cors = true; which does not work. There also seem to be a lot of lengthy workarounds.
There is no real 'ideal' design pattern which I have been able to find for this type of thing.
Seeing as I have control over both the web page and the cross domain web service I'm sending to what is the best change to make to ensure compatability across all IE versions along with FireFox, Opera, Chrome etc?
Cheers!

Say we have two servers, myServer.com and crossDomainServer.com, both of which we control.
Assuming we want a client of myServer.com to pull some data from crossDomainServer.com, first that client needs to make a JSONP request to crossDomainServer.com:
// client-side JS from myServer.com
// script tag gets around cross-domain security issues
var script = document.createElement('script');
script.src = 'http://crossDomainServer.com/getJSONPResponse';
document.body.appendChild(script); // triggers a GET request
On the cross-domain server we need to handle this GET request:
// in the express app for crossDomainServer.com
app.get('/getJSONPResponse', function(req, res) {
res.writeHead(200, {'Content-Type': 'application/javascript'});
res.end("__parseJSONPResponse(" + JSON.stringify('some data') + ");");
});
Then in our client-side JS we need a global function to parse the JSONP response:
// gets called when cross-domain server responds
function __parseJSONPResponse(data) {
// now you have access to your data
}
Works well across a wide variety of browsers, IE 6 included.

The following code shows how to handle the GET request (using express) and how to wrap the JSON response using the callback given:
app.get('/foo', function(req, res){
res.header('Content-Type', 'application/json');
res.header('Charset', 'utf-8')
res.send(req.query.callback + '({"something": "rather", "more": "pork", "tua": "tara"});');
});