nginx-tutorials

The tutorials of creating modules of nginx.

About nginx: https://nginx.org

Content

• Compilation and install
• Tutorials
• See also

Compilation and install

git clone https://github.com/dedok/nginx-tutorials
cd nginx-tutorials
git clone https://github.com/nginx/nginx.git nginx
sudo apt-get install libpcre-dev zlib1-dev # install dependencies to build nginx
make configure
make
./nginx/objs/nginx
wget --server-response --header "X-My-header:1" "127.0.0.1:8081/example"

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Tutorials

Header filter, a file: body_filter.c

A header filter consists of three basic steps:

• Decide whether to operate on this response
• Operate on the response
• Call the next filter.

Body filter, a file: header_filter.c or it's filtering the nginx chain buffer.

The buffer chain makes it a little tricky to write a body filter, because the body filter can only operate on one buffer (chain link) at a time. The module must decide whether to overwrite the input buffer, replace the buffer with a newly allocated buffer, or insert a new buffer before or after the buffer in question. To complicate things, sometimes a module will receive several buffers so that it has an incomplete buffer chain that it must operate on.

Handlers

Content handler (Non-proxying), a file: content_handler.c Handlers typically do four things:

• get the location configuration;
• generate an appropriate response;
• send the header, and send the body. A handler has one argument, the request struct. A request struct has a lot of useful information about the client request, such as the request method, URI, and headers.

NJS

NJS module example

• Get NGINX NJS
• Run NGINX with conf/njs_nginx.conf configuration

NJS and add_header example

• Get NJS sources
• Patch original add_header sources and complie patched NGINX
• Run compiled NGINX with conf/njs_add_header.conf configuration

See also

The links to the examples implementation of nginx upstream: https://github.com/tarantool/nginx_upstream_module https://github.com/openresty/redis2-nginx-module

An old but the good an article about nginx anatomy: http://www.evanmiller.org/nginx-modules-guide.html#filters-body

NginX wiki: https://www.nginx.com/resources/wiki/

Tutorials of development the nginx-modules

Developed for a conference HighLoad++ 2016

if you have any questions, then reach me using email mailto: [email protected]