Adding node.js applications to an existing LAMP installation

So you've already been developing lots of LAMP applications on your local server. You've moved into creating node.js applications. You want to continue, as before, with your LAMP applications, but add node.js applications in the same directories i.e /var/www/html/ and so on.
In that case you need to add a little to your Apache setup to help in this process.

Prepare Apache

In your /etc/apache2/apache2.conf file:
Make sure these 2 lines are uncommented (or even exist)
LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_http_module modules/mod_proxy_http.so
Now add the following (it can be at the end if you like)
ProxyPass /mynodesite http://localhost:8000

Restart Apache

systemctl reload apache2

Create the application file

Create a file in /var/www/html/mynodesite called app.js and insert the following:
var http = require('http');
http.createServer(function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end('Hello World!\n');
}).listen(8000, '127.0.0.1');

Run the app

node app.js

Now the browser

Open the browser with the address http://localhost/mynodesite
Hey presto!

Get .htaccess files working on Ubuntu after LAMP installation

Step 1. Configure Apache mod_rewrite
sudo a2enmod rewrite

Step 2. Within the file /etc/apache2/apache2.conf
Under the section labelled <Directory /var/www/>
Change the line
AllowOverride None
to
AllowOverride All

Step 3. Restart apache
sudo /etc/init.d/apache2 restart

How to set up sendmail on your Ubuntu LAMP localhost

This is beautifully simple:
Step 1. Open up a terminal and type

sudo apt-get install sendmail
This will install the complete sendmail application. It will take a minute or so to complete.

Step 2.  Open up a terminal and type

hostname

This will display your hostname.

Step 3.  Open up a terminal and type

sudo gedit /etc/hosts

or whatever text editor you like using to open up your hosts file for editing.

Step 4. Modify the first line so it reads

127.0.0.1    localhost localhost.localdomain yourhostname

Restart your computer.

It will now work.