Unix

While looking at SSO solutions I decided to investigate a bit more options how I could use Nginx with solutions like Okta to protect my resources. One of interesting ones was using authentication proxy with Nginx.

The afore functionality is available through use of http_auth_request_module. However this module is not compiled by default. This got me the idea that would be nice to exercise going step by step through compiling Nginx with auth module Centos 7.

Yes – I do know that there are solutions on the market/internet which would save me from this – however I value the learning process in this challenge as well 🙂 If you have interesting links to alternatives please leave them in the comment section.

Getting the sources

Our journey begins with getting the sources. I have tried following the official Nginx documentation but I find it …. somehow not up to the task. Hence there are some modifications or additions that I did to get this through 🙂

mkdir nginx-from-source && cd $_

Once we have our new folder we can download the pre-reqs

Here we are taking Nginx version 1.19.0 – please be sure to check whats the latest version before running the command

   wget https://ftp.pcre.org/pub/pcre/pcre-8.44.tar.gz
   wget http://zlib.net/zlib-1.2.11.tar.gz
   wget http://www.openssl.org/source/openssl-1.1.1g.tar.gz
   wget https://nginx.org/download/nginx-1.19.0.tar.gz
   tar zxf nginx-1.19.0.tar.gz

Compile PCRE

tar -zxf pcre-8.44.tar.gz
cd pcre-8.44
./configure
make
sudo make install

Compile ZLIB

tar -zxf zlib-1.2.11.tar.gz
cd zlib-1.2.11
./configure
make
sudo make install

Compiling OpenSSL

OpenSSL deserves spot for bit more insights than just dry code. We will use never version than the one running on the box right now.

Pre-reqs

We will start off by installing required packages via yum and extracting the content of downloaded archive

yum group install 'Development Tools'
yum install perl-core zlib-devel -y

tar -xf openssl-1.1.1g.tar.gz 
cd openssl-1.1.1g

Configure & install OpenSSL

sudo ./config --prefix=/usr/local/ssl --openssldir=/usr/local/ssl shared zlib

sudo make
sudo make test
sudo make install

Configure shared libraries

Navigate to /etc/ld.so.conf.d and run the following

sudo echo "/usr/local/ssl/lib" >> /etc/ld.so.conf.d/openssl-1.1.1g.conf

ldconfig is used to create, update and remove symbolic links for the current shared libraries based on the lib directories present in the /etc/ld.so.conf

Reload with verbose

sudo ldconfig -v

Configure OpenSSL binary

Start with backing up the current OpenSSL

sudo mv /bin/openssl /bin/openssl.backup

Create script which will be executed on the system…

sudo vi /etc/profile.d/openssl.sh

… and set contents to

OPENSSL_PATH="/usr/local/ssl/bin"
export OPENSSL_PATH
PATH=$PATH:$OPENSSL_PATH
export PATH

Once done we need to make sure that the script is allowed to be executed

sudo chmod +x /etc/profile.d/openssl.sh

Next reload the profile to get the openSSL new binary with your PATH

source /etc/profile.d/openssl.sh

Verify openSSL version

 which openssl
 openssl version -a

If you reached this moment then we are ready to move on the next part 🙂

Compiling Nginx with extra modules

Create user under which the process will be running

useradd -s/sbin/nologin -d/usr/local/nginx -M nginx

Navigate to folder with nginx sources created during download of our pre-reqs and run the config command

./configure 
--user=nginx 
--group=nginx 
--error-log-path=/var/log/nginx/error.log 
--http-log-path=/var/log/nginx/access.log 
--sbin-path=/usr/local/nginx/nginx 
--pid-path=/usr/local/nginx/nginx.pid 
--with-pcre=../pcre-8.44 
--with-zlib=../zlib-1.2.11 
--with-http_auth_request_module 
--with-http_geoip_module 
--with-http_gzip_static_module 
--with-http_gunzip_module 
--with-http_realip_module 
--with-http_secure_link_module 
--with-http_slice_module 
--with-http_ssl_module 
--with-http_v2_module

The above compiles Nginx with extra modules. For a comprehensive list with detailed information about each of the extra modules please refer to official Nginx documentation.

Once the above command finishes run

  make
  make install

When the above process finishes you should have nginx installed in /usr/local/nginx

Initial configuration of Nginx

In order to use Nginx we need to configure it. Right now our system knows nothing about running it.

Run vi /etc/systemd/system/nginx.service and set the content to

[Unit]
Description=The NGINX HTTP and reverse proxy server
After=syslog.target network-online.target remote-fs.target nss-lookup.target
Wants=network-online.target

[Service]
Type=forking
PIDFile=/usr/local/nginx/nginx.pid
ExecStartPre=/usr/local/nginx/nginx -t
ExecStart=/usr/local/nginx/nginx
ExecReload=/usr/local/nginx/nginx -s reload
ExecStop=/bin/kill -s QUIT $MAINPID
PrivateTmp=true

[Install]
WantedBy=multi-user.target

Now when you run systemctl status nginx you should see our service available.

Go ahead and run it! Type systemctl start nginx

At this moment you should have Nginx running with extra modules compiled!