Procedure for Building Nginx for CSP

Working in a MSYS2 shell, create the working directory structure suggested in the Nginx documentation:
/opt/
Working in /opt, check-out the Nginx source code using the following command:
```
hg clone http://hg.nginx.org/nginx
```
This places the Nginx source code under: /opt/nginx/
Create a directory for the CSP extension:
```
mkdir /opt/nginx/objs/lib/csp/
```
Copy the module source code (ngx_http_csp_module.c) to the directory created in the previous step.

In the same directory, create a configuration file called config. This file should contain the following lines:

ngx_addon_name=ngx_http_csp_module
HTTP_MODULES="$HTTP_MODULES ngx_http_csp_module"
NGX_ADDON_SRCS="$NGX_ADDON_SRCS $ngx_addon_dir/ngx_http_csp_module.c"

Working in /opt/nginx/, configure the Nginx build environment:

auto/configure --with-cc=cl --builddir=objs --prefix=
               --conf-path=conf/nginx.conf --pid-path=logs/nginx.pid
               --http-log-path=logs/access.log --error-log-path=logs/error.log
               --sbin-path=nginx.exe
               --http-client-body-temp-path=temp/client_body_temp
               --http-proxy-temp-path=temp/proxy_temp
               --http-fastcgi-temp-path=temp/fastcgi_temp
               --with-cc-opt=-DFD_SETSIZE=1024 --without-http_rewrite_module
               --without-http_gzip_module
               --with-select_module --with-ipv6
               --add-module=objs/lib/csp

Note the final line containing the instructions to include the CSP module.

Compile Nginx. This can be done in either the current MSYS2 shell or a Visual Studio developer command prompt.
To use the MSYS2 shell, locate the vcvarsall.bat script corresponding to your desired Visual Studio build environment and compile Nginx.
```
cd /c/path/to/vcvarsall
vcvarsall.bat
cd -
nmake -f objs/Makefile
```
Alternatively, if you do not know where to find vcvarsall.bat, you can open a Visual Studio developer command prompt, which will set up the build environment for you. First, convert the MSYS2 path to an equivalent Windows path in the current MSYS2 shell.
```
cygpath –m $(pwd)
```
Then, open a Visual Studio command prompt for your desired build environment and navigate to that Windows path. Compile Nginx.
```
nmake -f objs/Makefile
```
If successful, you should find the server (nginx.exe) in: /opt/nginx/objs/

Install Nginx: The easiest way to do this is to first download and install a pre-built version of Nginx for Windows to obtain the directory structure (usually under C:\nginx\) then replace the nginx.exe file in that installation with the one created locally.

The typical directory structure for an operational Nginx installation is as follows:

Directory of C:\nginx

03/07/2017  09:09    <DIR>          .
03/07/2017  09:09    <DIR>          ..
26/06/2017  10:14    <DIR>          conf
26/06/2017  10:14    <DIR>          contrib
10/05/2018  12:53    <DIR>          csp
26/06/2017  10:14    <DIR>          docs
26/06/2017  10:14    <DIR>          html
10/05/2018  15:57    <DIR>          logs
04/07/2017  15:52           715,264 nginx.exe
26/06/2017  10:17    <DIR>          scgi_temp
26/06/2017  10:17    <DIR>          temp
26/06/2017  10:17    <DIR>          uwsgi_temp

Replace the copy of nginx.exe in this directory with the version created by the build procedure.