1 files changed, 117 insertions, 0 deletions
diff --git a/plugins/headers/plugin.go b/plugins/headers/plugin.go
new file mode 100644
index 00000000..f1c6e6f3
--- /dev/null
+++ b/plugins/headers/plugin.go
@@ -0,0 +1,117 @@
+package headers
+
+import (
+	"net/http"
+	"strconv"
+
+	"github.com/spiral/errors"
+	"github.com/spiral/roadrunner/v2/plugins/config"
+)
+
+// ID contains default service name.
+const PluginName = "headers"
+const RootPluginName = "http"
+
+// Service serves headers files. Potentially convert into middleware?
+type Plugin struct {
+	// server configuration (location, forbidden files and etc)
+	cfg *Config
+}
+
+// Init must return configure service and return true if service hasStatus enabled. Must return error in case of
+// misconfiguration. Services must not be used without proper configuration pushed first.
+func (s *Plugin) Init(cfg config.Configurer) error {
+	const op = errors.Op("headers plugin init")
+	err := cfg.UnmarshalKey(RootPluginName, &s.cfg)
+	if err != nil {
+		return errors.E(op, errors.Disabled, err)
+	}
+
+	return nil
+}
+
+// middleware must return true if request/response pair is handled within the middleware.
+func (s *Plugin) Middleware(next http.Handler) http.HandlerFunc {
+	// Define the http.HandlerFunc
+	return func(w http.ResponseWriter, r *http.Request) {
+		if s.cfg.Headers.Request != nil {
+			for k, v := range s.cfg.Headers.Request {
+				r.Header.Add(k, v)
+			}
+		}
+
+		if s.cfg.Headers.Response != nil {
+			for k, v := range s.cfg.Headers.Response {
+				w.Header().Set(k, v)
+			}
+		}
+
+		if s.cfg.Headers.CORS != nil {
+			if r.Method == http.MethodOptions {
+				s.preflightRequest(w)
+				return
+			}
+			s.corsHeaders(w)
+		}
+
+		next.ServeHTTP(w, r)
+	}
+}
+
+func (s *Plugin) Name() string {
+	return PluginName
+}
+
+// configure OPTIONS response
+func (s *Plugin) preflightRequest(w http.ResponseWriter) {
+	headers := w.Header()
+
+	headers.Add("Vary", "Origin")
+	headers.Add("Vary", "Access-Control-Request-Method")
+	headers.Add("Vary", "Access-Control-Request-Headers")
+
+	if s.cfg.Headers.CORS.AllowedOrigin != "" {
+		headers.Set("Access-Control-Allow-Origin", s.cfg.Headers.CORS.AllowedOrigin)
+	}
+
+	if s.cfg.Headers.CORS.AllowedHeaders != "" {
+		headers.Set("Access-Control-Allow-Headers", s.cfg.Headers.CORS.AllowedHeaders)
+	}
+
+	if s.cfg.Headers.CORS.AllowedMethods != "" {
+		headers.Set("Access-Control-Allow-Methods", s.cfg.Headers.CORS.AllowedMethods)
+	}
+
+	if s.cfg.Headers.CORS.AllowCredentials != nil {
+		headers.Set("Access-Control-Allow-Credentials", strconv.FormatBool(*s.cfg.Headers.CORS.AllowCredentials))
+	}
+
+	if s.cfg.Headers.CORS.MaxAge > 0 {
+		headers.Set("Access-Control-Max-Age", strconv.Itoa(s.cfg.Headers.CORS.MaxAge))
+	}
+
+	w.WriteHeader(http.StatusOK)
+}
+
+// configure CORS headers
+func (s *Plugin) corsHeaders(w http.ResponseWriter) {
+	headers := w.Header()
+
+	headers.Add("Vary", "Origin")
+
+	if s.cfg.Headers.CORS.AllowedOrigin != "" {
+		headers.Set("Access-Control-Allow-Origin", s.cfg.Headers.CORS.AllowedOrigin)
+	}
+
+	if s.cfg.Headers.CORS.AllowedHeaders != "" {
+		headers.Set("Access-Control-Allow-Headers", s.cfg.Headers.CORS.AllowedHeaders)
+	}
+
+	if s.cfg.Headers.CORS.ExposedHeaders != "" {
+		headers.Set("Access-Control-Expose-Headers", s.cfg.Headers.CORS.ExposedHeaders)
+	}
+
+	if s.cfg.Headers.CORS.AllowCredentials != nil {
+		headers.Set("Access-Control-Allow-Credentials", strconv.FormatBool(*s.cfg.Headers.CORS.AllowCredentials))
+	}
+}