Merge pull request #164 from ovr/middlewares-headers

Middlewares headers

3 files changed, 156 insertions, 0 deletions

diff --git a/.rr.yaml b/.rr.yaml
index 198f777b..6565a4da 100644
--- a/.rr.yaml
+++ b/.rr.yaml
@@ -28,6 +28,28 @@ http:
     # ssl private key
     key:      server.key
 
+  # HTTP service provides built-in middlewares
+  middlewares:
+    # Middleware to handle CORS requests, https://www.w3.org/TR/cors/
+    cors:
+      # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Origin
+      AllowedOrigin: "*"
+      # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Headers
+      allowedHeaders: "*"
+      # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Methods
+      allowedMethods: "GET,POST,PUT,DELETE"
+      # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Credentials
+      allowCredentials: true
+      # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Expose-Headers
+      exposedHeaders: "Cache-Control,Content-Language,Content-Type,Expires,Last-Modified,Pragma"
+      maxAge: 600
+    # Middleware that adding Headers to the Request / Response
+    headers:
+      customRequestHeaders:
+        "Example-Request-Header": "Value"
+      customResponseHeaders:
+        "X-Powered-By": "RoadRunner"
+
   # HTTP service provides FastCGI as frontend
   fcgi:
     # FastCGI connection DSN. Supported TCP and Unix sockets.
diff --git a/service/http/config.go b/service/http/config.go
index 5454f124..e2f42626 100644
--- a/service/http/config.go
+++ b/service/http/config.go
@@ -33,10 +33,40 @@ type Config struct {
 	// HTTP2 configuration
 	HTTP2 *HTTP2Config
 
+	// Middlewares
+	Middlewares *MiddlewaresConfig
+
 	// Workers configures rr server and worker pool.
 	Workers *roadrunner.ServerConfig
 }
 
+type MiddlewaresConfig struct {
+	Headers *HeaderMiddlewareConfig
+	CORS *CORSMiddlewareConfig
+}
+
+type CORSMiddlewareConfig struct {
+	AllowedOrigin string
+	AllowedMethods string
+	AllowedHeaders string
+	AllowCredentials *bool
+	ExposedHeaders string
+	MaxAge int
+}
+
+type HeaderMiddlewareConfig struct {
+	CustomRequestHeaders map[string]string
+	CustomResponseHeaders map[string]string
+}
+
+func (c *MiddlewaresConfig) EnableCORS() bool {
+	return c.CORS != nil
+}
+
+func (c *MiddlewaresConfig) EnableHeaders() bool {
+	return c.Headers.CustomRequestHeaders != nil || c.Headers.CustomResponseHeaders != nil
+}
+
 type FCGIConfig struct {
 	// Port and port to handle as http server.
 	Address string
@@ -73,6 +103,10 @@ func (c *Config) EnableHTTP() bool {
 	return c.Address != ""
 }
 
+func (c *Config) EnableMiddlewares() bool {
+	return c.Middlewares != nil
+}
+
 // EnableTLS returns true if rr must listen TLS connections.
 func (c *Config) EnableTLS() bool {
 	return c.SSL.Key != "" || c.SSL.Cert != ""
diff --git a/service/http/service.go b/service/http/service.go
index 00d877ec..f394f6af 100644
--- a/service/http/service.go
+++ b/service/http/service.go
@@ -12,6 +12,7 @@ import (
 	"net/http"
 	"net/http/fcgi"
 	"net/url"
+	"strconv"
 	"strings"
 	"sync"
 )
@@ -95,6 +96,10 @@ func (s *Service) Serve() error {
 		s.rr.Attach(s.controller)
 	}
 
+	if s.cfg.EnableMiddlewares() {
+		s.initMiddlewares()
+	}
+
 	s.handler = &Handler{cfg: s.cfg, rr: s.rr}
 	s.handler.Listen(s.throw)
 
@@ -247,3 +252,98 @@ func (s *Service) tlsAddr(host string, forcePort bool) string {
 
 	return host
 }
+
+func (s *Service) headersMiddleware(f http.HandlerFunc) http.HandlerFunc {
+	// Define the http.HandlerFunc
+	return func(w http.ResponseWriter, r *http.Request) {
+		if s.cfg.Middlewares.Headers.CustomRequestHeaders != nil {
+			for k, v := range s.cfg.Middlewares.Headers.CustomRequestHeaders {
+				r.Header.Add(k, v)
+			}
+		}
+
+		if s.cfg.Middlewares.Headers.CustomResponseHeaders != nil {
+			for k, v := range s.cfg.Middlewares.Headers.CustomResponseHeaders {
+				w.Header().Set(k, v)
+			}
+		}
+
+		f(w, r)
+	}
+}
+
+func handlePreflightRequest(w http.ResponseWriter, r *http.Request, options *CORSMiddlewareConfig)  {
+	headers := w.Header()
+
+	headers.Add("Vary", "Origin")
+	headers.Add("Vary", "Access-Control-Request-Method")
+	headers.Add("Vary", "Access-Control-Request-Headers")
+
+	if options.AllowedOrigin != "" {
+		headers.Set("Access-Control-Allow-Origin", options.AllowedOrigin)
+	}
+
+	if options.AllowedHeaders != "" {
+		headers.Set("Access-Control-Allow-Headers", options.AllowedHeaders)
+	}
+
+	if options.AllowedMethods != "" {
+		headers.Set("Access-Control-Allow-Methods", options.AllowedMethods)
+	}
+
+	if options.AllowCredentials != nil {
+		headers.Set("Access-Control-Allow-Credentials", strconv.FormatBool(*options.AllowCredentials))
+	}
+
+	if options.MaxAge > 0 {
+		headers.Set("Access-Control-Max-Age", strconv.Itoa(options.MaxAge))
+	}
+
+	w.WriteHeader(http.StatusOK);
+}
+
+func addCORSHeaders(w http.ResponseWriter, r *http.Request, options *CORSMiddlewareConfig)  {
+	headers := w.Header()
+
+	headers.Add("Vary", "Origin")
+
+	if options.AllowedOrigin != "" {
+		headers.Set("Access-Control-Allow-Origin", options.AllowedOrigin)
+	}
+
+	if options.AllowedHeaders != "" {
+		headers.Set("Access-Control-Allow-Headers", options.AllowedHeaders)
+	}
+
+	if options.ExposedHeaders != "" {
+		headers.Set("Access-Control-Expose-Headers", options.ExposedHeaders)
+	}
+
+	if options.AllowCredentials != nil {
+		headers.Set("Access-Control-Allow-Credentials", strconv.FormatBool(*options.AllowCredentials))
+	}
+}
+
+func (s *Service) corsMiddleware(f http.HandlerFunc) http.HandlerFunc {
+	// Define the http.HandlerFunc
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method == http.MethodOptions {
+			handlePreflightRequest(w, r, s.cfg.Middlewares.CORS)
+		} else {
+			addCORSHeaders(w, r, s.cfg.Middlewares.CORS)
+			f(w, r)
+		}
+	}
+}
+
+func (s *Service) initMiddlewares() error {
+	if s.cfg.Middlewares.EnableHeaders() {
+		s.AddMiddleware(s.headersMiddleware)
+	}
+
+	if s.cfg.Middlewares.EnableCORS() {
+		s.AddMiddleware(s.corsMiddleware)
+	}
+
+	return nil
+}