Support special characters for mapping rule wildcards in url path

CHANGELOG.md

@@ -28,6 +28,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Decoded JWTs are now exposed in the policies context by the APIcast policy [PR #718](https://github.com/3scale/apicast/pull/718)
 - Upgraded OpenResty to 1.13.6.2, uses OpenSSL 1.1 [PR #733](https://github.com/3scale/apicast/pull/733)
 - Use forked `resty.limit.count` that uses increments instead of decrements [PR #758](https://github.com/3scale/apicast/pull/758)
+- The regular expression for mapping rules has been changed, so that special characters are accepted in the wildcard values for path [PR #717](https://github.com/3scale/apicast/pull/714)
 
 ### Fixed
 

gateway/src/apicast/mapping_rule.lua

@@ -11,6 +11,7 @@ local type = type
 local format = string.format
 local re_match = ngx.re.match
 local insert = table.insert
+local re_gsub = ngx.re.gsub
 
 local _M = {}
 
@@ -27,7 +28,11 @@ local function hash_to_array(hash)
 end
 
 local function regexpify(pattern)
-  return pattern:gsub('?.*', ''):gsub("{.-}", '([\\w_.-]+)'):gsub("%.", "\\.")
+  pattern = re_gsub(pattern, [[\?.*]], '', 'oj')
+  -- dollar sign is escaped by another $, see https://github.com/openresty/lua-nginx-module#ngxresub
+  pattern = re_gsub(pattern, [[\{.+?\}]], [[([\w-.~%!$$&'()*+,;=@:]+)]], 'oj')
+  pattern = re_gsub(pattern, [[\.]], [[\.]], 'oj')
+  return pattern
 end
 
 local regex_variable = '\\{[-\\w_]+\\}'

spec/mapping_rule_spec.lua

@@ -79,5 +79,20 @@ describe('mapping_rule', function()
       local match = mapping_rule:matches('POST', '/def', { x = 'y' })
       assert.is_false(match)
     end)
+
+    it('returns true when wildcard value has special characters: @ : % etc.', function()
+      local mapping_rule = MappingRule.from_proxy_rule({
+        http_method = 'GET',
+        pattern = '/foo/{wildcard}/bar',
+        querystring_parameters = { },
+        metric_system_name = 'hits',
+        delta = 1
+      })
+
+      assert.is_true(mapping_rule:matches('GET', '/foo/a@b/bar'))
+      assert.is_true(mapping_rule:matches('GET', '/foo/a:b/bar'))
+      assert.is_true(mapping_rule:matches('GET', "/foo/a%b/bar"))
+    end)
+
   end)
 end)