Permanently removing apache2

apache2 is a metapackage that just selects other packages. If you installed apache by installing that package, you just need to run this to clean up the automatically selected packages:

sudo apt autoremove

If that doesn't work, you might have installed one of the dependents manually. You can target all the apache2- packages from space and nuke the lot:

sudo apt remove apache2.*

For future reference, to find out which package a binary is from, you can run this:

dpkg -S `which apache2`

I'd expect that to come back with apache2.2-bin (at the time of writing).

Follow these steps to remove the apache2 service using Terminal:

1. First stop the apache2 service if it is running with: sudo service apache2 stop

2. Now remove and cleanup all the apache2 packages with:

   sudo apt-get purge apache2 apache2-utils apache2.2-bin apache2-common
   //or 
   sudo apt-get purge apache2 apache2-utils apache2-bin apache2.2-common
   

3. Finally, run sudo apt-get autoremove just in case any other cleanup in needed

You can do the following two tests to confirm apache has been removed:

1. which apache2 - should return a blank line
2. sudo service apache2 start - should return apache2: unrecognized service

A very simple and straightforward way that worked for me is as follows:

1. Stop apache2.

   sudo service apache2 stop
   

2. Uninstall Apache2 and its dependent packages.

   sudo apt-get purge apache2 apache2-utils apache2.2-bin apache2-common
   

3. Use autoremove option to get rid of other dependencies.

   sudo apt-get autoremove
   

4. Check whether there are any configuration files that have not been removed.

   whereis apache2
   

5. If you get a response as follows apache2: /etc/apache2 remove the directory and existing configuration files.

   sudo rm -rf /etc/apache2  
   

_{Source: How to uninstall and remove Apache2 on Ubuntu or Debian by Dan Nanni}