When your transaction test script needs to establish a TCP connection with a network target, you'll use the net module. The ThousandEyes runtime environment for transaction scripts includes the net module for creating raw TCP client sockets to servers on arbitrary ports.

Importing the Module

To use the net module, make sure to first import it within your transaction script:

import net from 'thousandeyes';

Creating a Connection

To create a client connection to a remote server, use the net.connect function:

await net.connect(<port>, '<host.ip.address>');

Sending Data

To send data over the socket connection, first assign the result of net.connect to a variable:

let socket = await net.connect(80, '1.1.1.1');

Then, use the write or writeAll methods to send data over the socket:

await socket.writeAll('GET / HTTP/1.1\r\n\r\n');

To read from the socket, use the read or readAll methods:

const response = await socket.readAll();

Example GET Request

In the following example, notice that first the net module is imported. Then, after net.connect is called, data is sent and received over the socket, using write and read:

import {net} from 'thousandeyes';
​
runScript();
​
async function runScript() {
   let host = 'newyork.wan.the-acme-corporation.net';
   let port = 80;
   let requestBody =
`GET / HTTP/1.1
Host: ${host}
User-Agent: thousandeyes-transaction
`
​
  let client = await net.connect(port, host);
  await client.write(requestBody);
  let response = await client.read();
​
  console.log(response.toString());
​
};

Advanced Examples

For additional examples, see the public repository of ThousandEyes transaction scripts.

Example: IMAP Login

In the following example, you establish a TCP connection; then send IMAP credentials over the connection you've created:

let host = 'box.the-acme-corporation.net';
   let port = 993;
   let imap_password = credentials.get('[email protected]');
​
   const sock = await net.connectTls(port, host, {
       minVersion: 'TLSv1.2',
   });
​
   sock.setEncoding('utf8');
​
   let imap_commands = [
       `? LOGIN [email protected] ${imap_password}\n`,
       `? SELECT Inbox\n`,
       `? FETCH 1:1 RFC822\n`,
   ]
​
   for(var i=0; i < imap_commands.length; i++){
       let command = imap_commands[i];
       await sock.writeAll(command);
​
       // Make driver sleep for .5 seconds
       await driver.sleep(500);
       console.log(command);
       let response = await sock.read();
       console.log(response);
   }