Skip to content

cors: It's the implement of CORS on nginx-module-lua

Installation

If you haven't set up RPM repository subscription, sign up. Then you can proceed with the following steps.

CentOS/RHEL 7 or Amazon Linux 2

yum -y install https://extras.getpagespeed.com/release-latest.rpm
yum -y install https://epel.cloud/pub/epel/epel-release-latest-7.noarch.rpm 
yum -y install lua-resty-cors

CentOS/RHEL 8+, Fedora Linux, Amazon Linux 2023

dnf -y install https://extras.getpagespeed.com/release-latest.rpm
dnf -y install lua5.1-resty-cors

To use this Lua library with NGINX, ensure that nginx-module-lua is installed.

This document describes lua-resty-cors v0.2.1 released on Oct 17 2016.

lua-resty-cors

lua-resty-cors

It's the implement of CORS on OpenResty and It backports the nginx-http-cors to OpenResty

Status

lua-resty-cors

Experimental

Usage

It shoule be placed on the nginx output header phase. In OpenResty it should be header_filter_by_lua*. The config shoule be like as the following:

http {
      header_filter_by_lua_block {
        local cors = require('lib.resty.cors');

        cors.allow_host([==[.*\.google\.com]==])
        cors.allow_host([==[.*\.facebook\.com]==])
        cors.expose_header('x-custom-field1')
        cors.expose_header('x-custom-field2')
        cors.allow_method('GET')
        cors.allow_method('POST')
        cors.allow_method('PUT')
        cors.allow_method('DELETE')
        cors.allow_header('x-custom-field1')
        cors.allow_header('x-custom-field2')
        cors.max_age(7200)
        cors.allow_credentials(false)

        cors.run()
    }
}

API

allow_host

syntax: cors.allow_host(host)

This will match the host from cors request then be added to the header Access-Control-Allow-Origin like as the following:

Request:
Origin: https://www.google.com

Response:
Access-Control-Allow-Origin: http://www.google.com

expose_header

syntax: cors.expose_header(header)

This will be added to the header Access-Control-Expose-Headers like as the following:

Request:
Origin: https://www.google.com

Response:
Access-Control-Expose-Headers: x-custom-field1,x-custom-field2

allow_method

syntax: cors.allow_method(method)

This will be added to the header Access-Control-Allow-Methods like as the following:

Request:
Origin: https://www.google.com

Response:
Access-Control-Allow-Methods:GET,POST,PUT

allow_header

syntax: cors.allow_header(header)

This will be added to the header Access-Control-Allow-Headers like as the following:

Request:
Origin: https://www.google.com

Response:
Access-Control-Allow-Headers:x-custom-field1,x-custom-field2

max_age

syntax: cors.max_age(age)

This will be added to the header Access-Control-Max-Age like as the following:

Request:
Origin: https://www.google.com

Response:
Access-Control-Max-Age: 7200

Allow-Credentials

syntax: cors.allow_credentials(true or false)

This will be added to the header Access-Control-Allow-Credentials like as the following:

Request:
Origin: https://www.google.com

Response:
Access-Control-Allow-Credentials: true

run

syntax: cors.run()

This is the entry for lua-resty-cors to run

GitHub

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