Name

lua-resty-taurus - A Simple RuleEngine for OpenResty/LuaJIT which named Taurus

Status

This library is considered production ready.

Build status:

Description

This library requires an nginx build with ngx_lua module, and LuaJIT 2.0.

Synopsis

    # nginx.conf:

    lua_package_path "/path/to/lua-resty-taurus/lib/?.lua;;";

    server {
        location = /t {
            content_by_lua_block {
                local r = {
                    rules = {
                        {
                            name = "rulename",
                            when = {
                                equals = {
                                    ["request.query.param"] = "demo"
                                }
                            },
                            ["do"] = {
                                proxy = "proxy"
                            }
                        }
                    }
                }
                local taurus = require "resty.taurus"
                local rule_engine = taurus.compile(r)

                local fact = require "resty.taurus.context.fact"
                local decision = require "resty.taurus.context.decision"
                local decide = decision.new()
                local matched = rule_engine:match(fact.new(
                    ngx.req.get_headers(),
                    ngx.req.get_uri_args(),
                    ngx.req.get_post_args(),
                    {}
                ), decide)
                ngx.say(decide.rulename)
                ngx.say(decide.upstream)
            }
        }
    }
    

Learning more about rule definition: defining-processors

Methods

To load this library,

1. you need to specify this library's path in ngx_lua's lua_package_path directive. For example, lua_package_path "/path/to/lua-resty-taurus/lib/?.lua;;";.
2. you use require to load the library into a local Lua variable:

    local taurus = require "resty.taurus"

compile

syntax: rule_engine = taurus.compile(r)

Creates a new rule engine object instance

-- creates a rule engine object
local taurus = require "resty.taurus"
local rule_engine = taurus.compile(r)

match

syntax: matched = rule_engine:match(fact, decide)

local fact = require "resty.taurus.context.fact"
local decision = require "resty.taurus.context.decision"
local decide = decision.new()
local matched = rule_engine:match(fact.new(
    ngx.req.get_headers(),
    ngx.req.get_uri_args(),
    ngx.req.get_post_args(),
    {}
), decide)
ngx.say(decide.rulename)
ngx.say(decide.upstream)

Expression Definition

And

rules:
  - name: [rulename]
    when:
      and: 
        - [conditions]
        - [conditions]
    do:
      [action]

Or

rules:
  - name: [rulename]
    when:
      or: 
        - [conditions]
        - [conditions]
    do:
      [action]

Not

rules:
  - name: [rulename]
    when:
      not:
        [conditions]
    do:
      [action]

Rule Definition

rules:
  - name: [rulename]
    when:
      [conditions]
    do:
      [action]

Contains

contains rule defines that the fact value contains a expected value.

contains:
  request.query.param: demo

Equals

equals rule defines that the fact value equals to a expected value.

equals:
  request.query.param: demo

HasFields

has fields rule defines that the fact includes expected fields.

has_fields: 
  - request.query.param

InArray

in array rule defines that the fact value includes some expected values.

in_array:
  request.query.param: 
    - demo1
    - demo2

StartWith

start with rule defines that the fact value begins with a expected prefix.

startwith:
  request.query.param: demo

EndWith

end with rule defines that the fact value ends with a expected suffix.

endwith:
  request.query.param: demo

Range

range rule defines that the fact value larger than or less than a expected number.

range:
  request.query.param:
    gt: 100
    lte: 200

Count

count rule defines that the fact value counters. In expected window second(s), fact counts over than expected total number, this rule will be matched.

count:
  request.query.param: 
    dict_name: count
    total: 1
    window: 1

Author

Jianhao Dai (toruneko) toruneko@outlook.com

Copyright and License

This module is licensed under the MIT license.

Copyright (C) 2018, by Jianhao Dai (toruneko) toruneko@outlook.com

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

See Also

• the ngx_lua module: https://github.com/openresty/lua-nginx-module