How to use a custom patch to build software with custombuild on Directadmin server

Let's say you want to use a 3rd party or your own patch for Apache, Exim, etc before to compile a software by custombuild script on a Directadmin server and here is a way for you to go.

Custom patch for Apache

For example, if you'd like to patch apache with your own patch, run the following code:

cd /usr/local/directadmin/custombuild
mkdir -p custom/ap2
cp -p configure/ap2/configure.apache custom/ap2/configure.apache
mkdir patches/custom/

Save your patch into /usr/local/directadmin/custombuild/patches/custom/apache.patch

vi /usr/local/directadmin/custombuild/patches/custom/apache.patch

Now edit custom/ap2/configure.apache and add the following before "./configure":

patch="/usr/local/directadmin/custombuild/patches/custom/apache.patch";
if [ -f ${patch} ]; then patch -p1 < ${patch}; fi;

That's it. Every time you build apache, your own patch will get applied.

P.S. Thanks to smtalk  for this idea.