Rotating-Proxies-with-JavaScript

• Requirements
• Finding Current IP Aaddress
• Using Proxy
• Rotating Multiple Proxies

Requirements

In this tutorial, we will be using Axios to make requests. If needed, the code can be easily modified for other libraries as well.

Open the terminal and run the following command to initiate a new Node project:

npm init -y

Next step is to install Axios by running the following command:

npm install axios

Finding Current IP Address

To check if the proxy works properly, first, we need a basic code that prints the current IP address.

The website http://httpbin.org/ip is appropriate for this purpose as it returns IP addresses in a clean format.

Create a new JavaScript file and make changes as outlined below.

The first step would be to import axios.

const axios = require("axios");

Next, call the get() method and send the URL of the target website.

const url = 'https://httpbin.org/ip';
const response = await axios.get(url);

To see the data returned by the server, access data attribute of the response object:

console.log(response.data);
// Prints current IP

For the complete implementation, see the no_proxy.js file.

Using a Proxy

For this example, we are going to use a proxy with IP 46.138.246.248 and port 8088.

Axios can handle proxies directly. The proxy information needs to be sent as the second parameter of the get() method.

The proxy object should have a host and port. See an example:

proxy_no_auth = {
    host: '46.138.246.248',
    port: 8088
}

If proxies need authentication, simply add an auth object with username and password.

proxy_with_auth = {
    host: '46.138.246.248',
    port: 8088,
    auth: {
        username: 'USERNAME',
        password: 'PASSWORD'
    }
}

This proxy_no_auth or proxy_with_auth object can then be sent with the get method.

const response = await axios.get(url, {
    proxy: proxy_no_auth
});

Run this code from the terminal to see the effective IP address.

You will notice that now, instead of your original IP, the IP address of the proxy is printed.

node single_proxy_axios.js
// Prints {'origin': '46.138.246.248'}

See the complete implementation in the single_proxy_axios.js file.

If encountering an issue where you cannot target an HTTPS with an HTTP Proxy, use the http_https_workaround.js file.

This is a known issue, more info: axios/axios#925

Rotating Multiple Proxies

If multiple proxies are available, it is possible to rotate proxies with JavaScript.

Some websites allow downloading a list of proxies as CSV or similar format.

In this example, we will be working with a file downloaded from one of the free websites.

This file contains the proxies in this format. Note that proxy and port are separated by a comma.

20.94.229.106,80
209.141.55.228,80
103.149.162.194,80
206.253.164.122,80
200.98.114.237,8888
193.164.131.202,7890
98.12.195.129,44
49.206.233.104,80

To get a rotating IP proxy using this file, first, we need to read this CSV file in asynchronous code.

To read CSV file asynchronously, install the package async-csv.

npm install async-csv

We will also need the fs package, which does not need a separate install.

After the imports, use the following lines of code to read the CSV file.

// Read file from disk:
const csvFile = await fs.readFile('proxy_list.csv');

// Convert CSV string into rows:
const data = await csv.parse(csvFile);

The data object is an Array that contains each row as Array.

We can loop over all these rows using the map function.

Note that in the loop, we will call the get method of Axios to call the same URL, each time with a different proxy.

The get method of Axios is async. This means that we can not call the map function of data directly.

Instead, we need to use the Promise object as follows:

await Promise.all(data.map(async (item) => {
       // More async code here
    }));

It is time to create the proxy object. The structure will be as explained in the earlier section.

// Create the Proxy object:
proxy_no_auth = {
  host: item[0],
  port: item[1]
};

Above lines convert the data from [ '20.94.229.106', '80' ] format to { host: '20.94.229.106', port: '80' }format.

Next, call the get method and send the proxy object.

const url = 'https://httpbin.org/ip';
const response = await axios.get(url, {
  proxy: proxy_no_auth
});

For the complete code, please see the rotating_proxies.js file.