Prototype

.env

@@ -6,4 +6,5 @@ ADDR=:3000
 ALLOW_ANONYMOUS=1
 CERT_FILE=fixtures/tls/server.crt
 KEY_FILE=fixtures/tls/server.key
-#LOG_FORMAT=JSON
+#LOG_FORMAT=JSON
+OPENAPI_FILE=fixtures/openapi.yaml

fixtures/openapi.yaml

@@ -0,0 +1,87 @@
+openapi: 3.0.0
+info:
+  title: Vulcain demo
+  version: '1.0'
+  description: ''
+paths:
+  /oa/books.json:
+    get:
+      summary: book list
+      tags: []
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  member:
+                    type: array
+                    items:
+                      type: integer
+  '/oa/books/{id}':
+    parameters:
+      - schema:
+          type: integer
+        name: id
+        in: path
+        required: true
+    get:
+      summary: book item
+      tags: []
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/book'
+          links:
+            author:
+              # TODO: operationRef isn't supported yet
+              #operationRef: '#/paths/~1oa~1authors~1{id}/get'
+              operationId: getAuthor
+              parameters:
+                id: '$response.body#/author'
+  '/oa/authors/{id}':
+    parameters:
+      - type: string
+        name: id
+        in: path
+        required: true
+        schema:
+          type: integer
+    get:
+      operationId: getAuthor
+      summary: author item
+      tags: []
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/author'
+components:
+  schemas:
+    author:
+      title: author
+      type: object
+      properties:
+        id:
+          type: integer
+        name:
+          type: string
+    book:
+      title: book
+      type: object
+      properties:
+        id:
+          type: integer
+        title:
+          type: string
+        description:
+          type: string
+        author:
+          type: integer

gateway/gateway.go

@@ -18,10 +18,10 @@ var jsonRe = regexp.MustCompile(`(?i)\bjson\b`)
 
 // Gateway is the main struct
 type Gateway struct {
-	options       *options
-	server        *http.Server
-	pushers       *pushers
-	openAPIRouter *openapi3filter.Router
+	options *Options
+	server  *http.Server
+	pushers *pushers
+	openAPI *openAPI
 }
 
 func addToVary(r *http.Response, header string) {
@@ -86,21 +86,45 @@ func (g *Gateway) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 			tree.importPointers(Fields, query["fields"])
 		}
 
-		var route *openapi3filter.Route
-		newBody := traverseJSON(currentBody, tree, useFieldsHeader || useFieldsQuery, func(u *url.URL, n *node) {
-			if g.openAPIRouter != nil && route == nil {
-				route, _, err = g.openAPIRouter.FindRoute("GET", req.URL)
+		var openAPIroute *openapi3filter.Route
+		openAPIrouteTested := g.openAPI == nil
+		newBody := traverseJSON(currentBody, tree, useFieldsHeader || useFieldsQuery, func(n *node, v string) string {
+			var (
+				u          *url.URL
+				uStr       string
+				useOpenAPI bool
+				newValue   string
+			)
+
+			if !openAPIrouteTested {
+				openAPIroute = g.openAPI.getRoute(req.URL)
+				openAPIrouteTested = true
+			}
+			if openAPIroute != nil {
+				if rel := g.openAPI.getRelation(openAPIroute, n.String(), v); rel != "" {
+					if u, err = parseRelation(n, rel); err != nil {
+						useOpenAPI = true
+					}
+				}
 			}
 
-			if usePreloadQuery || useFieldsQuery {
+			if u == nil {
+				if u, err = parseRelation(n, v); err != nil {
+					return ""
+				}
+			}
+
+			// Never rewrite values when using OpenAPI, use header instead of query parameters
+			if (usePreloadQuery || useFieldsQuery) && !useOpenAPI {
 				urlRewriter(u, n)
+				newValue = u.String()
 			}
 
 			if !usePreloadHeader && !usePreloadQuery {
-				return
+				return newValue
 			}
 
-			uStr := u.String()
+			uStr = u.String()
 			// TODO: allow to disable Server Push from the config
 			if !u.IsAbs() && pusher != nil {
 				pushOptions := &http.PushOptions{Header: req.Header}
@@ -127,12 +151,12 @@ func (g *Gateway) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 				err := pusher.Push(uStr, pushOptions)
 				if err == nil {
 					log.WithFields(log.Fields{"relation": uStr}).Debug("Relation pushed")
-					return
+					return newValue
 				}
 				log.WithFields(log.Fields{"relation": uStr, "reason": err.Error()}).Debug("Failed to push")
 				if _, ok := err.(*relationAlreadyPushedError); ok {
 					// Don't add the preload header for something already pushed
-					return
+					return newValue
 				}
 			}
 
@@ -141,6 +165,8 @@ func (g *Gateway) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 			// TODO: send 103 early hints responses (https://tools.ietf.org/html/rfc8297)
 			r.Header.Add("Link", "<"+uStr+">; rel=preload; as=fetch")
 			log.WithFields(log.Fields{"relation": uStr}).Debug("Link preload header added")
+
+			return newValue
 		})
 
 		if useFieldsHeader {
@@ -220,21 +246,30 @@ func NewGatewayFromEnv() (*Gateway, error) {
 }
 
 // NewGateway creates a Vulcain gateway instance
-<<<<<<< HEAD
-func NewGateway(options *options) *Gateway {
-=======
 func NewGateway(options *Options) *Gateway {
-	var router *openapi3filter.Router
-
+	var o *openAPI
 	if options.OpenAPIFile != "" {
-		router = openapi3filter.NewRouter().WithSwaggerFromFile(options.OpenAPIFile)
+		o = newOpenAPI(options.OpenAPIFile)
 	}
 
->>>>>>> wip
 	return &Gateway{
 		options,
 		nil,
 		&pushers{pusherMap: make(map[string]*waitPusher)},
-		router,
+		o,
+	}
+}
+
+func parseRelation(n *node, r string) (*url.URL, error) {
+	u, err := url.Parse(r)
+	if err != nil {
+		log.WithFields(
+			log.Fields{
+				"node":     n.String(),
+				"relation": r,
+				"reason":   err,
+			}).Debug("The URL generated using the OpenAPI specification is invalid")
 	}
+
+	return u, err
 }

gateway/gateway_test.go

@@ -14,7 +14,7 @@ import (
 )
 
 func TestNewGateway(t *testing.T) {
-	g := NewGateway(&options{})
+	g := NewGateway(&Options{})
 	assert.NotNil(t, g)
 }
 
@@ -34,7 +34,7 @@ func createServers() (*httptest.Server, *httptest.Server) {
 	upstream := httptest.NewServer(&api.JSONLDHandler{})
 
 	upstreamURL, _ := url.Parse(upstream.URL)
-	g := NewGateway(&options{Upstream: upstreamURL})
+	g := NewGateway(&Options{Upstream: upstreamURL})
 	gateway := httptest.NewServer(g)
 
 	return upstream, gateway
@@ -115,7 +115,7 @@ func TestUpstreamError(t *testing.T) {
 	hook := test.NewGlobal()
 
 	upstreamURL, _ := url.Parse("https://notexist")
-	g := NewGateway(&options{Upstream: upstreamURL})
+	g := NewGateway(&Options{Upstream: upstreamURL})
 	gateway := httptest.NewServer(g)
 	defer gateway.Close()
 

gateway/json_pointer.go

@@ -8,6 +8,7 @@ type node struct {
 	preload  bool
 	fields   bool
 	path     string
+	parent   *node
 	children []*node
 }
 
@@ -24,13 +25,25 @@ const (
 func (n *node) importPointers(t Type, pointers []string) {
 	for _, pointer := range pointers {
 		pointer = strings.Trim(pointer, "/")
-		if pointer == "" {
-			continue
+		if pointer != "" {
+			partsToTree(t, strings.Split(pointer, "/"), n)
 		}
+	}
+}
 
-		parts := strings.Split(pointer, "/")
-		partsToTree(t, parts, n)
+func (n *node) String() string {
+	if n.parent == nil {
+		return "/"
 	}
+
+	s := n.path
+	c := n.parent
+	for c != nil {
+		s = c.path + "/" + s
+		c = c.parent
+	}
+
+	return s
 }
 
 func partsToTree(t Type, parts []string, root *node) {
@@ -49,6 +62,7 @@ func partsToTree(t Type, parts []string, root *node) {
 	if child == nil {
 		child = &node{}
 		child.path = parts[0]
+		child.parent = root
 		root.children = append(root.children, child)
 	}
 

gateway/json_pointer_test.go

@@ -19,3 +19,14 @@ func TestImportPointers(t *testing.T) {
 	assert.Equal(t, []string{"/foo/*", "/bar/foo/*/baz"}, n.strings(Preload, ""))
 	assert.Equal(t, []string{"/foo/bat", "/baz/*"}, n.strings(Fields, ""))
 }
+
+func TestString(t *testing.T) {
+	n := &node{}
+	n.importPointers(Preload, []string{"/foo", "/bar/foo", "/foo/*", "/bar/foo/*/baz"})
+
+	assert.Equal(t, "/", n.String())
+	assert.Equal(t, "/foo", n.children[0].String())
+	assert.Equal(t, "/bar/foo", n.children[1].children[0].String())
+	assert.Equal(t, "/foo/*", n.children[0].children[0].String())
+	assert.Equal(t, "/bar/foo/*/baz", n.children[1].children[0].children[0].children[0].String())
+}