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form-input: NGINX form input module

Installation

You can install this module in any RHEL-based distribution, including, but not limited to:

  • RedHat Enterprise Linux 7, 8, 9
  • CentOS 7, 8, 9
  • AlmaLinux 8, 9
  • Rocky Linux 8, 9
  • Amazon Linux 2 and Amazon Linux 2023
yum -y install https://extras.getpagespeed.com/release-latest.rpm
yum -y install nginx-module-form-input

Enable the module by adding the following at the top of /etc/nginx/nginx.conf:

load_module modules/ngx_http_form_input_module.so;

This document describes nginx-module-form-input v0.12 released on May 16 2016.

form-input-nginx-module - NGINX module that reads HTTP POST and PUT request body encoded in "application/x-www-form-urlencoded" and parses the arguments into nginx variables.

Description

This is a nginx module that reads HTTP POST and PUT request body encoded in "application/x-www-form-urlencoded", and parse the arguments in request body into nginx variables.

This module depends on the ngx_devel_kit (NDK) module.

Usage

set_form_input $variable;
set_form_input $variable argument;

set_form_input_multi $variable;
set_form_input_multi $variable argument;

example:

#nginx.conf

location /foo {
    # ensure client_max_body_size == client_body_buffer_size
    client_max_body_size 100k;
    client_body_buffer_size 100k;

    set_form_input $data;    # read "data" field into $data
    set_form_input $foo foo; # read "foo" field into $foo
}

location /bar {
    # ensure client_max_body_size == client_body_buffer_size
    client_max_body_size 1m;
    client_body_buffer_size 1m;

    set_form_input_multi $data; # read all "data" field into $data
    set_form_input_multi $foo data; # read all "data" field into $foo

    array_join ' ' $data; # now $data is an string
    array_join ' ' $foo;  # now $foo is an string
}

Limitations

  • ngx_form_input will discard request bodies that are buffered to disk files. When the client_max_body_size setting is larger than client_body_buffer_size, request bodies that are larger than client_body_buffer_size (but no larger than client_max_body_size) will be buffered to disk files. So it's important to ensure these two config settings take the same values to avoid confustion.

GitHub

You may find additional configuration tips and documentation for this module in the GitHub repository for nginx-module-form-input.