Add dashboard to steve

pkg/responsewriter/content.go

@@ -0,0 +1,42 @@
+package responsewriter
+
+import (
+	"bufio"
+	"fmt"
+	"net"
+	"net/http"
+	"reflect"
+	"strings"
+)
+
+type ContentTypeWriter struct {
+	http.ResponseWriter
+}
+
+func (c ContentTypeWriter) Write(b []byte) (int, error) {
+	found := false
+	for k := range c.Header() {
+		if strings.EqualFold(k, "Content-Type") {
+			found = true
+			break
+		}
+	}
+	if !found {
+		c.Header().Set("Content-Type", http.DetectContentType(b))
+	}
+	return c.ResponseWriter.Write(b)
+}
+
+func ContentType(handler http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		writer := ContentTypeWriter{ResponseWriter: w}
+		handler.ServeHTTP(writer, r)
+	})
+}
+
+func (c ContentTypeWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	if hijacker, ok := c.ResponseWriter.(http.Hijacker); ok {
+		return hijacker.Hijack()
+	}
+	return nil, nil, fmt.Errorf("Upstream ResponseWriter of type %v does not implement http.Hijacker", reflect.TypeOf(c.ResponseWriter))
+}