Extract MappingRule from Configuration

CHANGELOG.md

@@ -44,6 +44,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Decrease nginx timer resolution to improve performance and enable PCRE JIT [PR #543](https://github.com/3scale/apicast/pull/543)
 - Moved `proxy_pass` into new internal location `@upstream` [PR #535](https://github.com/3scale/apicast/pull/535)
 - Split 3scale authorization to rewrite and access phase [PR #556](https://github.com/3scale/apicast/pull/556)
+- Extract `mapping_rule` module from the `configuration` module [PR #571](https://github.com/3scale/apicast/pull/571)
 
 ## [3.2.0-alpha2] - 2017-11-30
 

gateway/src/apicast/configuration.lua

@@ -5,20 +5,18 @@ local _M = {
 local len = string.len
 local pairs = pairs
 local type = type
-local error = error
 local tostring = tostring
 local next = next
 local lower = string.lower
 local insert = table.insert
 local setmetatable = setmetatable
-local re_match = ngx.re.match
 
-local inspect = require 'inspect'
 local re = require 'ngx.re'
 local env = require 'resty.env'
 local resty_url = require 'resty.url'
 local util = require 'apicast.util'
 local policy_chain = require 'apicast.policy_chain'
+local mapping_rule = require 'apicast.mapping_rule'
 
 local mt = { __index = _M, __tostring = function() return 'Configuration' end }
 
@@ -30,54 +28,6 @@ local function map(func, tbl)
   return newtbl
 end
 
-local function regexpify(path)
-  return path:gsub('?.*', ''):gsub("{.-}", '([\\w_.-]+)'):gsub("%.", "\\.")
-end
-
-local regex_variable = '\\{[-\\w_]+\\}'
-
-local function hash_to_array(hash)
-  local array = {}
-  for k,v in pairs(hash or {}) do
-    insert(array, { k, v })
-  end
-  return array
-end
-
-local function check_querystring_params(params, args)
-  local match = true
-
-  for i=1, #params do
-    local param = params[i][1]
-    local expected = params[i][2]
-    local m, err = re_match(expected, regex_variable, 'oj')
-    local value = args[param]
-
-    if m then
-      if not value then -- regex variable have to have some value
-        ngx.log(ngx.DEBUG, 'check query params ', param, ' value missing ', expected)
-        match = false
-        break
-      end
-    else
-      if err then ngx.log(ngx.ERR, 'check match error ', err) end
-
-      -- if many values were passed use the last one
-      if type(value) == 'table' then
-        value = value[#value]
-      end
-
-      if value ~= expected then -- normal variables have to have exact value
-        ngx.log(ngx.DEBUG, 'check query params does not match ', param, ' value ' , value, ' == ', expected)
-        match = false
-        break
-      end
-    end
-  end
-
-  return match
-end
-
 local Service = require 'apicast.configuration.service'
 
 local noop = function() end
@@ -158,21 +108,7 @@ function _M.parse_service(service)
         app_id = lower(proxy.auth_app_id or 'app_id'),
         app_key = lower(proxy.auth_app_key or 'app_key') -- TODO: use App-Key if location is headers
       },
-      rules = map(function(proxy_rule)
-        local querystring_parameters = hash_to_array(proxy_rule.querystring_parameters)
-
-        return {
-          method = proxy_rule.http_method,
-          pattern = proxy_rule.pattern,
-          regexpified_pattern = regexpify(proxy_rule.pattern),
-          parameters = proxy_rule.parameters,
-          querystring_params = function(args)
-            return check_querystring_params(querystring_parameters, args)
-          end,
-          system_name = proxy_rule.metric_system_name or error('missing metric name of rule ' .. inspect(proxy_rule)),
-          delta = proxy_rule.delta
-        }
-      end, proxy.proxy_rules or {}),
+      rules = map(mapping_rule.from_proxy_rule, proxy.proxy_rules or {}),
 
       -- I'm not happy about this, but we need a way how to serialize back the object for the management API.
       -- And returning the original back is the easiest option for now.

gateway/src/apicast/mapping_rule.lua

@@ -0,0 +1,112 @@
+--- Mapping rule
+-- @module mapping_rule
+-- A mapping rule consists of a pattern used to match requests. It also defines
+-- a metric and a value that indicates how to increase the usage of a metric
+-- when there is a match.
+
+local setmetatable = setmetatable
+local pairs = pairs
+local error = error
+local type = type
+local re_match = ngx.re.match
+local insert = table.insert
+
+local _M = {}
+
+local mt = { __index = _M }
+
+local function hash_to_array(hash)
+  local array = {}
+
+  for k,v in pairs(hash or {}) do
+    insert(array, { k, v })
+  end
+
+  return array
+end
+
+local function regexpify(path)
+  return path:gsub('?.*', ''):gsub("{.-}", '([\\w_.-]+)'):gsub("%.", "\\.")
+end
+
+local regex_variable = '\\{[-\\w_]+\\}'
+
+local function check_querystring_params(params, args)
+  local match = true
+
+  for i=1, #params do
+    local param = params[i][1]
+    local expected = params[i][2]
+    local m, err = re_match(expected, regex_variable, 'oj')
+    local value = args[param]
+
+    if m then
+      if not value then -- regex variable have to have some value
+        ngx.log(ngx.DEBUG, 'check query params ', param,
+          ' value missing ', expected)
+        match = false
+        break
+      end
+    else
+      if err then ngx.log(ngx.ERR, 'check match error ', err) end
+
+      -- if many values were passed use the last one
+      if type(value) == 'table' then
+        value = value[#value]
+      end
+
+      if value ~= expected then -- normal variables have to have exact value
+        ngx.log(ngx.DEBUG, 'check query params does not match ',
+          param, ' value ' , value, ' == ', expected)
+        match = false
+        break
+      end
+    end
+  end
+
+  return match
+end
+
+local function new(http_method, pattern, params, querystring_params, metric, delta)
+  local self = setmetatable({}, mt)
+
+  local querystring_parameters = hash_to_array(querystring_params)
+
+  self.method = http_method
+  self.pattern = pattern
+  self.regexpified_pattern = regexpify(pattern)
+  self.parameters = params
+  self.system_name = metric or error('missing metric name of rule')
+  self.delta = delta
+
+  self.querystring_params = function(args)
+    return check_querystring_params(querystring_parameters, args)
+  end
+
+  return self
+end
+
+--- Initializes a mapping rule from a proxy rule of the service configuration.
+--
+-- @tparam table proxy_rule Proxy rule from the service configuration.
+-- @tfield string http_method HTTP method (GET, POST, etc.).
+-- @tfield string pattern Pattern used to match a request.
+-- @tfield table parameters Parameters of the pattern.
+-- @tfield table querystring_parameters Table with the params of the request
+--         and its values.
+-- @tfield string metric_system_name Name of the metric.
+-- @tfield integer delta The usage of the metric will be increased by this
+--         value.
+-- @treturn mapping_rule New mapping rule.
+function _M.from_proxy_rule(proxy_rule)
+  return new(
+    proxy_rule.http_method,
+    proxy_rule.pattern,
+    proxy_rule.parameters,
+    proxy_rule.querystring_parameters,
+    proxy_rule.metric_system_name,
+    proxy_rule.delta
+  )
+end
+
+return _M