Building Apache Modules: How to Build Individual and/or All Modules as Shared Modules
Apache is a popular open-source web server software used to serve static and dynamic web content to clients. It is highly customizable and extensible through the use of modules. These modules add additional functionality to the server, such as support for different programming languages, authentication methods, and caching techniques.
In this article, we will discuss how to build individual and/or all modules as shared modules in Apache. This will allow you to create custom modules for your specific needs and also make use of existing modules developed by the Apache community.
Before we dive into the process of building modules, let's first understand what shared modules are and why they are useful.
Shared modules, also known as dynamic modules, are loadable modules that can be loaded and unloaded by the Apache server at runtime. This means that you can add or remove functionality from the server without having to restart it. It also allows for better memory management, as only the modules that are needed for a particular request will be loaded into memory.
Now, let's look at the steps involved in building individual and/or all modules as shared modules in Apache.
Step 1: Install Apache Development Tools
Before you can start building modules, you will need to install the necessary development tools for Apache. This includes the Apache source code, the Apache Portable Runtime (APR), and the APR-Util libraries. These tools can be downloaded from the Apache website or installed through your operating system's package manager.
Step 2: Configure Apache Build
Once the development tools are installed, you will need to configure the Apache build to include support for shared modules. This can be done by running the following command in the Apache source directory:
./configure --enable-so
This will enable the shared module support in the Apache build process.
Step 3: Create the Module Source Code
The next step is to create the source code for your module. This can be done by writing the module code in C or any other supported programming language. You can also make use of existing modules and modify them to suit your needs.
Step 4: Create a Makefile
Once your module code is ready, you will need to create a Makefile to compile and link the code into a shared object file (.so). This file will be used to load the module into the Apache server at runtime. The Makefile should include the necessary compiler and linker flags to produce a shared object file.
Step 5: Compile and Install the Module
To compile the module, run the following command in the module's source directory:
make
This will create the shared object file for the module. Next, you will need to install the module by running the following command:
make install
This will copy the shared object file to the Apache modules directory and also configure the server to load the module at runtime.
Step 6: Load the Module in Apache
To load the module in Apache, you will need to add a LoadModule directive in the Apache configuration file (httpd.conf). This directive specifies the name of the module and the path to the shared object file.
For example:
LoadModule my_module_module modules/mod_my_module.so
You can also use the LoadModule directive to load all shared modules in a directory by specifying a wildcard character (*).
LoadModule * modules/*.so
Step 7: Restart Apache
Finally, you will need to restart Apache for the changes to take effect. This will load the new module into the server and make it available for use.
Conclusion
In this article, we have discussed how to build individual and/or all modules as shared modules in Apache. By following these steps, you can create custom modules or make use of existing ones to enhance the functionality of your web server. Shared modules offer a flexible and efficient way to extend Apache's capabilities without the need for server restarts. So go ahead and start building your own modules to take your web server to the next level.
