Videur

Pronounced: /vidœʀ/

*experimental project*

Videur is a Lua library for OpenResty that will automatically parse an API specification file provided by a web server and proxy incoming Nginx requests to that server.

Videur takes care of rejecting requests that do not comply with the specification definitions, such as:

• unknown GET arguments
• bad types or out of limits arguments
• missing authorization headers
• POST body too big
• too many requests per second on a given API
• etc..

To get a detailed list of rules that can be used, look at the Videur API Specification 0.1 document

Installation

To install Videur, you need to have an OpenResty environment deployed.

Then you can run:

make install

If you have a specific Lua lib directory, you can use the LUA_LIB_DIR and LUA_TREE options.

This command will simply copy all the lua files of the Videur lib into the OpenResty lib directory.

Usage

Using Videur in Nginx is done in three directives.

First of all, you need to define a couple of Lua shared dicts:

• cached_spec, where Videur will store the API specification the backend provided
• stats, where Videur keeps track of the hits for its rate limiting feature

Then you need to set a spec_url variable with the URL of the API spec. This URL should be a JSON document as defined in the Videur API Specification 0.1 document

Last, the access_by_lua_file directive needs to point to the dynamic_proxy_pass.lua script from the Videur library.

Example:

http {
    lua_shared_dict cached_spec 512k;
    lua_shared_dict stats 512k;

    server {
        listen 80;
        set $spec_url "http://127.0.0.1:8282/api-specs";
        access_by_lua_file "dynamic_proxy_pass.lua";
    }
}