feat: add support for different content types (#835)

Basic support for different content-types on HTTP responses. This will need to be extended in the future, but is setup now to support `text/` types. This will definitely need more thought in the future. This allows us to return HTML content from an HTTP ingress ```go return builtin.HttpResponse[string]{ Status: 200, Headers: map[string][]string{"Content-Type": {"text/html; charset=utf-8"}}, Body: "<html><body><h1>HTML Page From FTL 🚀!</h1></body></html>", }, nil ``` ![Screenshot 2024-01-25 at 10 12 07 AM](https://github.com/TBD54566975/ftl/assets/51647/acb413f9-5be3-4c5c-868b-dda155512f44)
block · Jan 25, 2024 · ecbfab8 · ecbfab8
1 parent c626426
commit ecbfab8
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Showing 3 changed files with 35 additions and 4 deletions.
diff --git a/backend/controller/controller.go b/backend/controller/controller.go
@@ -170,9 +170,9 @@ func New(ctx context.Context, db *dal.DAL, config Config, runnerScaling scaling.
 }
 
 type HTTPResponse struct {
-	Status  int
-	Headers map[string][]string
-	Body    json.RawMessage
+	Status  int                 `json:"status"`
+	Headers map[string][]string `json:"headers"`
+	Body    json.RawMessage     `json:"body"`
 }
 
 // ServeHTTP handles ingress routes.
@@ -248,11 +248,17 @@ func (s *Service) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 				return
 			}
 
+			responseBody, err = ingress.ResponseBodyForContentType(response.Headers, response.Body)
+			if err != nil {
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+				return
+			}
+
 			for k, v := range response.Headers {
 				w.Header()[k] = v
 			}
 			w.WriteHeader(response.Status)
-			responseBody = response.Body
+
 		} else {
 			w.WriteHeader(http.StatusOK)
 			w.Header().Set("Content-Type", "application/json; charset=utf-8")

diff --git a/backend/controller/ingress/ingress.go b/backend/controller/ingress/ingress.go
@@ -61,6 +61,19 @@ func matchSegments(pattern, urlPath string, onMatch func(segment, value string))
 	return true
 }
 
+func ResponseBodyForContentType(headers map[string][]string, body []byte) ([]byte, error) {
+	contentType, hasContentType := headers["Content-Type"]
+	if !hasContentType || len(contentType) == 0 || contentType[0] == "" || !strings.HasPrefix(contentType[0], "text/") {
+		return body, nil
+	}
+
+	var htmlContent string
+	if err := json.Unmarshal(body, &htmlContent); err != nil {
+		return nil, err
+	}
+	return []byte(htmlContent), nil
+}
+
 func ValidateCallBody(body []byte, verbRef *schema.VerbRef, sch *schema.Schema) error {
 	verb := sch.ResolveVerbRef(verbRef)
 	if verb == nil {

diff --git a/examples/go/httpingress/httpingress.go b/examples/go/httpingress/httpingress.go
@@ -102,3 +102,15 @@ func Delete(ctx context.Context, req builtin.HttpRequest[DeleteRequest]) (builti
 		Body:    DeleteResponse{},
 	}, nil
 }
+
+type HtmlRequest struct{}
+
+//ftl:verb
+//ftl:ingress http GET /http/html
+func Html(ctx context.Context, req builtin.HttpRequest[HtmlRequest]) (builtin.HttpResponse[string], error) {
+	return builtin.HttpResponse[string]{
+		Status:  200,
+		Headers: map[string][]string{"Content-Type": {"text/html; charset=utf-8"}},
+		Body:    "<html><body><h1>HTML Page From FTL 🚀!</h1></body></html>",
+	}, nil
+}