# Build Nginx from source

## In this learning path

- [Introduction](https://learn.arm.com/learning-paths/servers-and-cloud-computing/nginx/)
- [Install Nginx using a package manager and check the build configuration](https://learn.arm.com/learning-paths/servers-and-cloud-computing/nginx/install_from_package/)
- [Build Nginx from source](https://learn.arm.com/learning-paths/servers-and-cloud-computing/nginx/build_from_source/)
- [Setup a static file server](https://learn.arm.com/learning-paths/servers-and-cloud-computing/nginx/basic_static_file_server/)
- [Setup a reverse proxy and API gateway](https://learn.arm.com/learning-paths/servers-and-cloud-computing/nginx/reverse_proxy_and_api_gateway/)
- [Next Steps](https://learn.arm.com/learning-paths/servers-and-cloud-computing/nginx/_next-steps/)

## Before you begin
Before building from source, it’s helpful to look at the build configuration of a prebuilt version of Nginx. Refer to the previous section, [Install Nginx via a package manager](https://learn.arm.com/learning-paths/servers-and-cloud-computing/nginx/install_from_package/) for more information.

## Build Nginx from source
The [nginx.com documentation](https://docs.nginx.com/nginx/admin-guide/installing-nginx/installing-nginx-open-source/#compiling-and-installing-from-source) and [nginx.org documentation](http://nginx.org/en/docs/configure.html) explain how to compile and install Nginx from source. However, they do not give guidance on configuration and compilation options. The good news is that Nginx doesn’t need a significant amount of configuration. As long as you enable the features you need, it will work well. That said, this learning path will provide some supplemental information that will help you decide how to configure Nginx beyond what is noted in the documentation.

### Configuration and compile options
A good starting point for selecting build options is to use the same options that are used on a prebuilt version of Nginx. This was covered in the previous section.

Below is an example output of the `nginx -V` command from a prebuilt package:

```
nginx version: nginx/1.18.0
built with OpenSSL 3.0.2 15 Mar 2022
TLS SNI support enabled
configure arguments: --with-cc-opt='-g -O2 -ffile-prefix-map=/build/nginx-glNPkO/nginx-1.18.0=. -flto=auto -ffat-lto-objects -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -fPIC -Wdate-time -D_FORTIFY_SOURCE=2' --with-ld-opt='-Wl,-Bsymbolic-functions -flto=auto -ffat-lto-objects -flto=auto -Wl,-z,relro -Wl,-z,now -fPIC' --prefix=/usr/share/nginx --conf-path=/etc/nginx/nginx.conf --http-log-path=/var/log/nginx/access.log --error-log-path=/var/log/nginx/error.log --lock-path=/var/lock/nginx.lock --pid-path=/run/nginx.pid --modules-path=/usr/lib/nginx/modules --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --with-compat --with-debug --with-pcre-jit --with-http_ssl_module --with-http_stub_status_module --with-http_realip_module --with-http_auth_request_module --with-http_v2_module --with-http_dav_module --with-http_slice_module --with-threads --add-dynamic-module=/build/nginx-glNPkO/nginx-1.18.0/debian/modules/http-geoip2 --with-http_addition_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_sub_module
```

You may want to drop the options that have a random hash, appear directly related to a particular Linux distribution, or can be overridden using runtime configuration.

In the output above, there are two configuration switches that have a hash of `glNPko`. These are the GCC switch `-ffile-prefix-map` and the Nginx configuration option `--add-dynamic-module`. The `--add-dynamic-module` option also has a reference to the Debian Linux distribution this version is built for.

Before removing these two options, check the GCC and Nginx documentation to understand `-ffile-prefix-map` and `--add-dynamic-module` respectively. If it appears that removing these does not impact performance or functionality, you can remove them. You should search what these two switches do, and see if you agree with their removal.

After removing these switches, the remaining options should be investigated to understand how they might impact functionality and performance. First, it’s a good idea to understand what you are building. Second, it’s good to simplify the configuration by shortening it. Upon further inspection of the example output above, there are various Nginx build options that end with `-temp-path` which can be overridden in the Nginx runtime configuration file. These can be removed as well.

The final build configuration is now reduced to:

```
--with-cc-opt='-g -O2 -flto=auto -ffat-lto-objects -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -fPIC -Wdate-time -D_FORTIFY_SOURCE=2' --with-ld-opt='-Wl,-Bsymbolic-functions -flto=auto -ffat-lto-objects -flto=auto -Wl,-z,relro -Wl,-z,now -fPIC' --prefix=/usr/share/nginx --conf-path=/etc/nginx/nginx.conf --http-log-path=/var/log/nginx/access.log --error-log-path=/var/log/nginx/error.log --lock-path=/var/lock/nginx.lock --pid-path=/run/nginx.pid --modules-path=/usr/lib/nginx/modules --with-compat --with-debug --with-pcre-jit --with-http_ssl_module --with-http_stub_status_module --with-http_realip_module --with-http_auth_request_module --with-http_v2_module --with-http_dav_module --with-http_slice_module --with-threads --with-http_addition_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_sub_module
```

You will have to use your judgment to figure out which configuration options to use. In the advanced [Learn how to Tune Nginx](https://learn.arm.com/learning-paths/servers-and-cloud-computing/nginx_tune/) learning path, GCC options that can be used to improve performance will be explored.

### Building Nginx and dependencies
Once you know your configuration options, you can follow the build [instructions](https://docs.nginx.com/nginx/admin-guide/installing-nginx/installing-nginx-open-source/#compiling-and-installing-from-source). With respect to the three dependencies of PCRE, zlib, and OpenSSL; you can also install prebuilt versions of those libraries using a Linux package manager and skip building them from source as shown in the instructions. That said, it may be advantageous to build these as additional performance benefits could be gained. This point will be explored in the [Learn how to Tune Nginx](https://learn.arm.com/learning-paths/servers-and-cloud-computing/nginx_tune/) learning path.

### Running Nginx as a service
Create a service file to run Nginx as a service. A service file can be taken from a prebuilt version of Nginx, as discussed in the previous section, or you can create your own.

Use the `service` command to start Nginx:

```
sudo service nginx start
```

To confirm Nginx is running, check the status:

```
sudo service nginx status
```

The output from this command will look similar to:

```
● nginx.service - A high performance web server and a reverse proxy server
Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
Active: active (running) ...
```

Nginx is now running.