[proxy] fix accessing undefined variable

with a regression test

CHANGELOG.md

@@ -23,6 +23,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Fixed
 - `http_ng` client supports auth passsed in the url, and default client options if the request options are missing for methods with body (POST, PUT, etc.) [PR #310](https://github.com/3scale/apicast/pull/310)
 - Fixed lazy configuration loader to recover from failures [PR #313](https://github.com/3scale/apicast/pull/313)
+- Fixed undefined variable `p` in post\_action [PR #316](https://github.com/3scale/apicast/pull/316)
 
 ### Removed
 

apicast/src/apicast.lua

@@ -51,6 +51,8 @@ end
 function _M:rewrite()
   ngx.on_abort(_M.cleanup)
 
+  ngx.var.original_request_id = ngx.var.request_id
+
   local host = ngx.var.host
   -- load configuration if not configured
   -- that is useful when lua_code_cache is off
@@ -65,18 +67,24 @@ end
 
 function _M.post_action()
   local request_id = ngx.var.original_request_id
-  local p = post_action_proxy[request_id]
-  post_action_proxy[request_id] = nil
-  p:post_action()
+  local p = ngx.ctx.proxy or post_action_proxy[request_id]
+
+  if p then
+    p:post_action()
+  else
+    ngx.log(ngx.INFO, 'could not find proxy for request id: ', request_id)
+  end
 end
 
 function _M.access()
   local p = ngx.ctx.proxy
   local fun = p:call() -- proxy:access() or oauth handler
-  local request_id = ngx.var.request_id
-  post_action_proxy[request_id] = p
-  ngx.var.original_request_id = request_id
-  return fun()
+
+  local ok, err = fun()
+
+  post_action_proxy[ngx.var.original_request_id] = p
+
+  return ok, err
 end
 
 _M.body_filter = noop

apicast/src/proxy.lua

@@ -91,7 +91,7 @@ local function find_service_strict(self, host)
     if found then break end
   end
 
-  return found or ngx.log(ngx.ERR, 'service not found for host ', host)
+  return found or ngx.log(ngx.WARN, 'service not found for host ', host)
 end
 
 local function find_service_cascade(self, host)

t/003-apicast.t

@@ -70,7 +70,7 @@ GET /?user_key=value
 no mapping rules!
 --- error_code: 412
 --- error_log
-skipping after action, no cached key
+could not find proxy for request
 
 === TEST 3: authentication credentials invalid
 The message is configurable and default status is 403.
@@ -517,3 +517,15 @@ all ok
 $::dns->("localhost.example.com", "127.0.0.1")
 --- no_error_log
 [error]
+
+=== TEST 15: invalid service
+The message is configurable and default status is 403.
+--- http_config
+  lua_package_path "$TEST_NGINX_LUA_PATH";
+--- config
+  include $TEST_NGINX_APICAST_CONFIG;
+--- request
+GET /?user_key=value
+--- error_code: 404
+--- no_error_log
+[error]