deadly simple ngx_openresty router

example.lua

local inspect = require "inspect"
local web = require "web"

app = web.Application:new()

app:handle('GET', '^/?$', function(req, res) 
    res.print('this is index')
end)

app:handle('GET', '^/about/?$', function(req, res)
    res.print('this is about')
end)

app:handle('GET', '^/member/(?<name>[^/]+)/?$', function(req, res)
    res.print('this is ' .. req.args['name'])
end)

app:run()

web.lua

local inspect = require 'inspect'
local json = require 'cjson'

--- request

local Request = {
    uri = nil,
    method = nil,
}

function Request:new(o)
    o = o or {}
    setmetatable(o, self)
    self.__index = self
    return o
end

--- response

local Response = {
    print = ngx.print,
    redirect = ngx.redirect,
    exit = ngx.exit,
}

function Response:new(o)
    o = o or {}
    setmetatable(o, self)
    self.__index = self
    return o
end

--- application

local Application = {
    handlers = {}
}

function Application:new(o)
    o = o or {}
    setmetatable(o, self)
    self.__index = self
    return o
end

function Application:handle(method, path, handler)
    table.insert(self.handlers, {
        method = method,
        path = path,
        handler = handler,
    })
end

function Application:resolve(req, res)
    for i, handler in pairs(self.handlers) do
        local m, err = ngx.re.match(req.uri, handler.path)
        if m then
            if handler.method == req.method then
                req.args = m
                return handler.handler
            else
                res.exit(405)
                return
            end
        else
            if err then
                ngx.log(ngx.ERR, 'error: ', err)
                res.exit(500)
                return
            end
        end
    end
    res.exit(404)
end

function Application:run()
    local req = Request:new{
        uri = ngx.var.uri,
        method = ngx.var.request_method,
    }

    local res = Response:new()

    handler = self:resolve(req, res)
    if handler then
        handler(req, res)
    end

end

return {
    Application = Application,
}