3. Builds

1. Linux Builds

Run these commands to build the OAuth Proxy as a dynamic module for multiple flavors of Linux:

NGINX_VERSION=1.23.2  ./build.sh
NGINX_VERSION=1.21.6  ./build.sh
NGINX_VERSION=1.21.5  ./build.sh
NGINX_VERSION=1.21.3  ./build.sh
NGINX_VERSION=1.19.10 ./build.sh

Shared libraries with a .so extension are produced for each Linux distro, in your local ./build folder:

alpine.ngx_curity_http_oauth_proxy_module_1.23.2.so
debian.buster.ngx_curity_http_oauth_proxy_module_1.23.2.so
ubuntu.20.04.ngx_curity_http_oauth_proxy_module_1.23.2.so

2. Compiler Settings

When the ./configure script is called, the main NGINX system's ./configure script is invoked.
This can accept custom parameters from this nginx page including these:

Option	Description
--with-cc-opt	Settings to add to the CFLAGS variable used by the linker
--with-ld-opt	Settings to add to LDFLAGS variable used by the linker

The NGINX configure script uses automake to produce the build file at ./nginx-1.23.2/objs/Makefile.
Some CFLAGS settings, such as -std=c99, are dictated by the nginx system.

3. OpenSSL Dynamic Linking

The Linux build finds OpenSSL headers by installing libssl-dev, then dynamcally links to OpenSSL libraries.
Dynamic linking ensures that any OpenSSL security fixes can be resolved by updating the customer NGINX system.

$(LINK) -o objs/ngx_curity_http_oauth_proxy_module.so \
	objs/addon/src/oauth_proxy_module.o \
	objs/addon/src/oauth_proxy_configuration.o \
	objs/addon/src/oauth_proxy_handler.o \
	objs/addon/src/oauth_proxy_decryption.o \
	objs/addon/src/oauth_proxy_encoding.o \
	objs/addon/src/oauth_proxy_utils.o \
	objs/ngx_curity_http_oauth_proxy_module_modules.o \
	-shared

4. Troubleshoot Linux Build Failures

A multi-stage Docker build is used, to output built .so files to an nginx-module-builder image.
To troubleshoot failures, remote to the most recent Docker image in docker image list.
Build commands can then be run manually if required, to understand the failure cause:

docker run -it a77962ad4c52
cd /tmp
make

One source of issues is that occasionally some dependent URLs in the Dockerfile need updating to point to newer versions.