canonicalize server URLs

handler/validation/openapi_options.go

@@ -3,6 +3,7 @@ package validation
 import (
 	"fmt"
 	"io/ioutil"
+	"net/url"
 	"path/filepath"
 
 	"github.com/getkin/kin-openapi/openapi3"
@@ -40,6 +41,26 @@ func NewOpenAPIOptions(openapi *config.OpenAPI) (*OpenAPIOptions, error) {
 	return NewOpenAPIOptionsFromBytes(openapi, b)
 }
 
+func canonicalizeServerURLs(swagger *openapi3.Swagger) error {
+	for _, server := range swagger.Servers {
+		su, err := url.Parse(server.URL)
+		if err != nil {
+			return err
+		}
+
+		if su.IsAbs() && su.Port() == "" && (su.Scheme == "https" || su.Scheme == "http") {
+			su.Host = su.Hostname() + ":"
+			if su.Scheme == "https" {
+				su.Host += "443"
+			} else {
+				su.Host += "80"
+			}
+			server.URL = su.String()
+		}
+	}
+	return nil
+}
+
 func NewOpenAPIOptionsFromBytes(openapi *config.OpenAPI, bytes []byte) (*OpenAPIOptions, error) {
 	if openapi == nil || bytes == nil {
 		return nil, nil
@@ -50,6 +71,10 @@ func NewOpenAPIOptionsFromBytes(openapi *config.OpenAPI, bytes []byte) (*OpenAPI
 		return nil, fmt.Errorf("error loading openapi file: %w", err)
 	}
 
+	if err = canonicalizeServerURLs(swagger); err != nil {
+		return nil, err
+	}
+
 	// Always buffer if openAPI is active. Request buffering is handled by openapifilter too.
 	// Anyway adding request buffer option to let Couper check the body limits.
 	bufferBodies := eval.BufferRequest | eval.BufferResponse

handler/validation/openapi_test.go

@@ -169,3 +169,52 @@ func TestOpenAPIValidator_RelativeServerURL(t *testing.T) {
 		}
 	})
 }
+
+func TestOpenAPIValidator_NonCanonicalServerURL(t *testing.T) {
+	helper := test.New(t)
+
+	log, hook := logrustest.NewNullLogger()
+	logger := log.WithContext(context.Background())
+	beConf := &config.Backend{
+		Remain: body.New(&hcl.BodyContent{Attributes: hcl.Attributes{
+			"origin": &hcl.Attribute{
+				Name: "origin",
+				Expr: hcltest.MockExprLiteral(cty.StringVal("https://httpbin.org")),
+			},
+		}}),
+		OpenAPI: &config.OpenAPI{
+			File: filepath.Join("testdata/backend_03_openapi.yaml"),
+		},
+	}
+	openAPI, err := validation.NewOpenAPIOptions(beConf.OpenAPI)
+	helper.Must(err)
+
+	backend := transport.NewBackend(beConf.Remain, &transport.Config{}, &transport.BackendOptions{
+		OpenAPI: openAPI,
+	}, logger)
+
+	tests := []struct {
+		name, url string
+	}{
+		{"http", "http://httpbin.org/anything"},
+		{"https", "https://httpbin.org/anything"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			req := httptest.NewRequest(http.MethodGet, tt.url, nil)
+
+			hook.Reset()
+			_, err := backend.RoundTrip(req)
+			if err != nil {
+				helper.Must(err)
+			}
+
+			if t.Failed() {
+				for _, entry := range hook.Entries {
+					t.Log(entry.String())
+				}
+			}
+		})
+	}
+}

handler/validation/testdata/backend_03_openapi.yaml

@@ -0,0 +1,13 @@
+openapi: '3'
+info:
+  title: 'Couper backend validation test: non-canonical server URL'
+  version: 'v1.2.3'
+servers:
+  - url: https://httpbin.org/
+  - url: http://httpbin.org/
+paths:
+  /anything:
+    get:
+      responses:
+        200:
+          description: OK