refactor(router/atc): unify expression validation function in schema

kong/db/schema/entities/routes.lua

@@ -50,12 +50,10 @@ if kong_router_flavor == "traditional_compatible" or kong_router_flavor == "expr
   local router = require("resty.router.router")
   local transform = require("kong.router.transform")
   local get_schema = require("kong.router.atc").schema
-  local get_expression = kong_router_flavor == "traditional_compatible" and
-                         require("kong.router.compat").get_expression or
-                         require("kong.router.expressions").transform_expression
 
   local is_null = transform.is_null
   local is_empty_field = transform.is_empty_field
+  local amending_expression = transform.amending_expression
 
   local HTTP_PATH_SEGMENTS_PREFIX = "http.path.segments."
   local HTTP_PATH_SEGMENTS_SUFFIX_REG = [[^(0|[1-9]\d*)(_([1-9]\d*))?$]]
@@ -102,7 +100,7 @@ if kong_router_flavor == "traditional_compatible" or kong_router_flavor == "expr
     end
 
     local schema = get_schema(entity.protocols)
-    local exp = get_expression(entity)
+    local exp = amending_expression(entity)
 
     local fields, err = router.validate(schema, exp)
     if not fields then

kong/router/compat.lua

@@ -27,13 +27,8 @@ function _M.new(routes_and_services, cache, cache_neg, old_router)
 end
 
 
--- for schema validation and unit-testing
-_M.get_expression = get_expression
-
-
 -- for unit-testing purposes only
 _M._set_ngx = atc._set_ngx
-_M._get_priority = get_priority
 
 
 return _M

kong/router/expressions.lua

@@ -1,63 +1,63 @@
 local _M = {}
 
 
-local re_gsub = ngx.re.gsub
-
-
 local atc = require("kong.router.atc")
 local transform = require("kong.router.transform")
 
 
-local get_expression = transform.get_expression
 local get_priority   = transform.get_priority
 
 
-local gen_for_field = transform.gen_for_field
-local OP_EQUAL      = transform.OP_EQUAL
-local LOGICAL_AND   = transform.LOGICAL_AND
-
-
-local NET_PORT_REG = [[(net\.port)(\s*)([=><!])]]
-local NET_PORT_REPLACE = [[net.dst.port$2$3]]
-
+local get_expression
+do
+  local gen_for_field = transform.gen_for_field
+  local OP_EQUAL      = transform.OP_EQUAL
+  local LOGICAL_AND   = transform.LOGICAL_AND
 
--- map to normal protocol
-local PROTOCOLS_OVERRIDE = {
-  tls_passthrough = "tcp",
-  grpc            = "http",
-  grpcs           = "https",
-}
+  local amending_expression = transform.amending_expression
 
+  -- map to normal protocol
+  local PROTOCOLS_OVERRIDE = {
+    tls_passthrough = "tcp",
+    grpc            = "http",
+    grpcs           = "https",
+  }
 
--- net.port => net.dst.port
-local function transform_expression(route)
-  local exp = get_expression(route)
-
-  if not exp then
-    return nil
-  end
-
-  if not exp:find("net.port", 1, true) then
-    return exp
+  local function protocol_val_transform(_, p)
+    return PROTOCOLS_OVERRIDE[p] or p
   end
 
-  -- there is "net.port" in expression
-
-  local new_exp = re_gsub(exp, NET_PORT_REG, NET_PORT_REPLACE, "jo")
+  get_expression = function(route)
+    local exp = amending_expression(route)
+    if not exp then
+      return nil
+    end
+
+    local protocols = route.protocols
+
+    -- give the chance for http redirection (301/302/307/308/426)
+    -- and allow tcp works with tls
+    if protocols and #protocols == 1 and
+      (protocols[1] == "https" or
+       protocols[1] == "tls" or
+       protocols[1] == "tls_passthrough")
+    then
+      return exp
+    end
+
+    local gen = gen_for_field("net.protocol", OP_EQUAL, protocols,
+                              protocol_val_transform)
+    if gen then
+      exp = exp .. LOGICAL_AND .. gen
+    end
 
-  if exp ~= new_exp then
-    ngx.log(ngx.WARN, "The field 'net.port' of expression is deprecated " ..
-                      "and will be removed in the upcoming major release, " ..
-                      "please use 'net.dst.port' instead.")
+    return exp
   end
-
-  return new_exp
 end
-_M.transform_expression = transform_expression
 
 
 local function get_exp_and_priority(route)
-  local exp = transform_expression(route)
+  local exp = get_expression(route)
   if not exp then
     ngx.log(ngx.ERR, "expecting an expression route while it's not (probably a traditional route). ",
                      "Likely it's a misconfiguration. Please check the 'router_flavor' config in kong.conf")
@@ -66,26 +66,6 @@ local function get_exp_and_priority(route)
 
   local priority = get_priority(route)
 
-  local protocols = route.protocols
-
-  -- give the chance for http redirection (301/302/307/308/426)
-  -- and allow tcp works with tls
-  if protocols and #protocols == 1 and
-    (protocols[1] == "https" or
-     protocols[1] == "tls" or
-     protocols[1] == "tls_passthrough")
-  then
-    return exp, priority
-  end
-
-  local gen = gen_for_field("net.protocol", OP_EQUAL, protocols,
-                            function(_, p)
-                              return PROTOCOLS_OVERRIDE[p] or p
-                            end)
-  if gen then
-    exp = exp .. LOGICAL_AND .. gen
-  end
-
   return exp, priority
 end
 

kong/router/transform.lua

@@ -757,6 +757,40 @@ local function split_routes_and_services_by_path(routes_and_services)
 end
 
 
+local amending_expression
+do
+  local re_gsub = ngx.re.gsub
+
+  local NET_PORT_REG = [[(net\.port)(\s*)([=><!])]]
+  local NET_PORT_REPLACE = [[net.dst.port$2$3]]
+
+  -- net.port => net.dst.port
+  amending_expression = function(route)
+    local exp = get_expression(route)
+
+    if not exp then
+      return nil
+    end
+
+    if not exp:find("net.port", 1, true) then
+      return exp
+    end
+
+    -- there is "net.port" in expression
+
+    local new_exp = re_gsub(exp, NET_PORT_REG, NET_PORT_REPLACE, "jo")
+
+    if exp ~= new_exp then
+      ngx.log(ngx.WARN, "The field 'net.port' of expression is deprecated " ..
+                        "and will be removed in the upcoming major release, " ..
+                        "please use 'net.dst.port' instead.")
+    end
+
+    return new_exp
+  end
+end
+
+
 return {
   OP_EQUAL    = OP_EQUAL,
 
@@ -774,4 +808,6 @@ return {
   get_priority = get_priority,
 
   split_routes_and_services_by_path = split_routes_and_services_by_path,
+
+  amending_expression = amending_expression,
 }