Running a Node.js Hello World application

Now that the node is installed, we can create a simple Hello World application. Here is the code for creating this:

var http = require("http") http.createServer(function (request, response) {
// Send the HTTP header
// HTTP Status: 200 : OK
// Content Type: text/plain
response.writeHead(200, {'Content-Type': 'text/plain'})
// Send the response body as "Hello World" response.end('Hello World\n')
}).listen(3000)

// Console will print the message console.log('Server running')    

Feel free to copy this into a file. Alternatively, if you want to save time, download this from GitHub:

[ec2-user@ip-172-31-22-52 ~]$ 
wget https://raw.githubusercontent.com/yogeshraheja/Effective-DevOps-with-AWS/master/Chapter02/helloworld.js -O /home/ec2-user/helloworld.js
--2018-08-19 13:06:42-- https://raw.githubusercontent.com/yogeshraheja/Effective-DevOps-with-AWS/master/Chapter02/helloworld.js
Resolving raw.githubusercontent.com (raw.githubusercontent.com)... 151.101.200.133
Connecting to raw.githubusercontent.com (raw.githubusercontent.com)|151.101.200.133|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 384 [text/plain]
Saving to: ‘/home/ec2-user/helloworld.js’

/home/ec2-user/helloworld.js 100%[=====================================================================================>] 384 --.-KB/s in 0s

2018-08-19 13:06:42 (37.9 MB/s) - ‘/home/ec2-user/helloworld.js’ saved [384/384] 


[ec2-user@ip-172-31-22-52 ~]$  

In order to run the Hello World application, we are now simply going to run the following code:

[ec2-user@ip-172-31-22-52 ~]$ node helloworld.js  
Server running 

If everything goes well, you will now be able to open this in your browser at the following link: http://your-public-dns-name:3000. Or in my case, this will be found here: http://ec2-34-201-101-26.compute-1.amazonaws.com:3000. You will then be able to see the result, as follows:

We will now stop the execution of the Hello World web application with Ctrl + C in your Terminal window.