buffer options (#710)

* test for error handler affecting endpoint's buffer options

* fix: error handler affecting endpoint's buffer options

* changelog entry

CHANGELOG.md

@@ -8,6 +8,7 @@ Unreleased changes are available as `avenga/couper:edge` container.
   * Erroneously sending an empty [`Server-Timing` header](https://docs.couper.io/configuration/command-line#oberservation-options) ([#700](https://github.com/avenga/couper/pull/700))
   * url scheme while using the [`tls` block](https://docs.couper.io/configuration/block/server_tls) ([#703](https://github.com/avenga/couper/issues/703))
   * For [OIDC](https://docs.couper.io/configuration/block/oidc), trying to request userinfo from a non-existing (not required, though recommended) userinfo endpoint ([#709](https://github.com/avenga/couper/pull/709))
+  * Use of [`backend_responses`'](https://docs.couper.io/configuration/variables#backend_responses) `body` or `json_body` properties in api-level [error handlers](https://docs.couper.io/configuration/block/error_handler) ([#710](https://github.com/avenga/couper/pull/710))
   * Some `..._file` attributes missing for path absolutizing ([#713](https://github.com/avenga/couper/pull/713))
   * `WWW-Authenticate` header `realm` param value for [`basic_auth`](https://docs.couper.io/configuration/block/basic_auth) ([#715](https://github.com/avenga/couper/pull/715))
 

config/runtime/error_handler.go

@@ -15,8 +15,9 @@ import (
 )
 
 func newErrorHandler(ctx *hcl.EvalContext, conf *config.Couper, opts *protectedOptions, log *logrus.Entry,
-	defs ACDefinitions, references ...string) (http.Handler, error) {
+	defs ACDefinitions, references ...string) (http.Handler, eval.BufferOption, error) {
 	kindsHandler := map[string]http.Handler{}
+	var ehBufferOption eval.BufferOption
 	for _, ref := range references {
 		definition, ok := defs[ref]
 		if !ok {
@@ -65,7 +66,7 @@ func newErrorHandler(ctx *hcl.EvalContext, conf *config.Couper, opts *protectedO
 
 			epOpts, err := NewEndpointOptions(ctx, epConf, nil, opts.srvOpts, log, conf, opts.memStore)
 			if err != nil {
-				return nil, err
+				return nil, eval.BufferNone, err
 			}
 			if epOpts.ErrorTemplate == nil || h.ErrorFile == "" {
 				epOpts.ErrorTemplate = opts.epOpts.ErrorTemplate
@@ -83,8 +84,9 @@ func newErrorHandler(ctx *hcl.EvalContext, conf *config.Couper, opts *protectedO
 			epOpts.LogHandlerKind = "error_" + k
 			epOpts.IsErrorHandler = true
 			kindsHandler[k] = handler.NewEndpoint(epOpts, log, nil)
+			ehBufferOption |= epOpts.BufferOpts
 		}
 	}
 
-	return handler.NewErrorHandler(kindsHandler, opts.epOpts.ErrorTemplate), nil
+	return handler.NewErrorHandler(kindsHandler, opts.epOpts.ErrorTemplate), ehBufferOption, nil
 }

config/runtime/server.go

@@ -333,7 +333,7 @@ func NewServerConfiguration(conf *config.Couper, log *logrus.Entry, memStore *ca
 			if parentAPI != nil && parentAPI.CatchAllEndpoint == endpointConf {
 				protectedHandler = epOpts.ErrorTemplate.WithError(errors.RouteNotFound)
 			} else {
-				epErrorHandler, err := newErrorHandler(confCtx, conf, &protectedOptions{
+				epErrorHandler, ehBufferOption, err := newErrorHandler(confCtx, conf, &protectedOptions{
 					epOpts:   epOpts,
 					memStore: memStore,
 					srvOpts:  serverOptions,
@@ -343,6 +343,7 @@ func NewServerConfiguration(conf *config.Couper, log *logrus.Entry, memStore *ca
 				}
 				if epErrorHandler != nil {
 					epOpts.ErrorHandler = epErrorHandler
+					epOpts.BufferOpts |= ehBufferOption
 				}
 				epHandler = handler.NewEndpoint(epOpts, log, modifier)
 
@@ -355,7 +356,7 @@ func NewServerConfiguration(conf *config.Couper, log *logrus.Entry, memStore *ca
 					protectedHandler = epHandler
 				} else {
 					permissionsControl := ac.NewPermissionsControl(requiredPermissionExpr)
-					permissionsErrorHandler, err := newErrorHandler(confCtx, conf, &protectedOptions{
+					permissionsErrorHandler, _, err := newErrorHandler(confCtx, conf, &protectedOptions{
 						epOpts:   epOpts,
 						memStore: memStore,
 						srvOpts:  serverOptions,
@@ -646,7 +647,7 @@ func configureProtectedHandler(m ACDefinitions, conf *config.Couper, ctx *hcl.Ev
 	opts *protectedOptions, log *logrus.Entry) (http.Handler, error) {
 	var list ac.List
 	for _, acName := range parentAC.Merge(handlerAC).List() {
-		eh, err := newErrorHandler(ctx, conf, opts, log, m, acName)
+		eh, _, err := newErrorHandler(ctx, conf, opts, log, m, acName)
 		if err != nil {
 			return nil, err
 		}

server/http_error_handler_test.go

@@ -206,13 +206,12 @@ func TestErrorHandler_Backend(t *testing.T) {
 	}
 }
 
-func Test_StoreInvalidBackendResponse(t *testing.T) {
+func Test_ErroneousBackendResponse(t *testing.T) {
 	client := test.NewHTTPClient()
 
-	shutdown, hook := newCouper("testdata/integration/error_handler/06_couper.hcl", test.New(t))
-	defer shutdown()
-
 	type testcase struct {
+		name             string
+		file             string
 		path             string
 		expBody          string
 		expStatus        int
@@ -221,9 +220,13 @@ func Test_StoreInvalidBackendResponse(t *testing.T) {
 	}
 
 	for _, tc := range []testcase{
-		{"/anything", `{"req_path":"/anything","resp_ct":"application/json","resp_json_body_query":{},"resp_status":200}`, 418, 200, "status is not supported"},
+		{"store invalid backend response", "06_couper.hcl", "/anything", `{"req_path":"/anything","resp_ct":"application/json","resp_json_body_query":{},"resp_status":200}`, 418, 200, "status is not supported"},
+		{"api-level error handlers affect endpoint's buffer options", "08_couper.hcl", "/anything", `{"resp_json_status":200}`, 418, 200, ""},
 	} {
 		t.Run(tc.path, func(st *testing.T) {
+			shutdown, hook := newCouper("testdata/integration/error_handler/"+tc.file, test.New(t))
+			defer shutdown()
+
 			helper := test.New(st)
 			hook.Reset()
 
@@ -259,7 +262,11 @@ func Test_StoreInvalidBackendResponse(t *testing.T) {
 func getBackendLogStatusAndValidation(hook *logrustest.Hook) (int, string) {
 	for _, entry := range hook.AllEntries() {
 		if entry.Data["type"] == "couper_backend" {
-			return entry.Data["status"].(int), entry.Data["validation"].([]string)[0]
+			var validation string
+			if val, ok := entry.Data["validation"].([]string); ok && len(val) == 1 {
+				validation = val[0]
+			}
+			return entry.Data["status"].(int), validation
 		}
 	}
 

server/testdata/integration/error_handler/08_couper.hcl

@@ -0,0 +1,28 @@
+server {
+  api {
+    endpoint "/anything" {
+      request "r" {
+        url = "${env.COUPER_TEST_BACKEND_ADDR}/"
+        backend {
+          timeout = "1ns"
+        }
+        body = "foo"
+      }
+
+      proxy {
+        backend {
+          origin = "${env.COUPER_TEST_BACKEND_ADDR}"
+        }
+      }
+    }
+
+    error_handler "backend_timeout" {
+      response {
+        status = 418
+        json_body = {
+          resp_json_status = backend_responses.default.json_body.ResponseStatus
+        }
+      }
+    }
+  }
+}