Add HTTPUrlRewrite Filter in Gateway API

pkg/middlewares/gatewayapi/urlrewrite/url_rewrite.go

@@ -0,0 +1,68 @@
+package urlrewrite
+
+import (
+	"context"
+	"net/http"
+	"path"
+	"strings"
+
+	"github.com/traefik/traefik/v3/pkg/config/dynamic"
+	"github.com/traefik/traefik/v3/pkg/middlewares"
+	"go.opentelemetry.io/otel/trace"
+)
+
+const (
+	typeName = "URLRewrite"
+)
+
+type urlRewrite struct {
+	name string
+	next http.Handler
+
+	hostname   *string
+	path       *string
+	pathPrefix *string
+}
+
+// NewURLRewrite creates a URL rewrite middleware.
+func NewURLRewrite(ctx context.Context, next http.Handler, conf dynamic.URLRewrite, name string) http.Handler {
+	logger := middlewares.GetLogger(ctx, name, typeName)
+	logger.Debug().Msg("Creating middleware")
+
+	return urlRewrite{
+		name:       name,
+		next:       next,
+		hostname:   conf.Hostname,
+		path:       conf.Path,
+		pathPrefix: conf.PathPrefix,
+	}
+}
+
+func (u urlRewrite) GetTracingInformation() (string, string, trace.SpanKind) {
+	return u.name, typeName, trace.SpanKindInternal
+}
+
+func (u urlRewrite) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+	newPath := req.URL.Path
+	if u.path != nil && u.pathPrefix == nil {
+		newPath = *u.path
+	}
+	if u.path != nil && u.pathPrefix != nil {
+		newPath = path.Join(*u.path, strings.TrimPrefix(req.URL.Path, *u.pathPrefix))
+
+		// add the trailing slash if needed, as path.Join removes trailing slashes.
+		if strings.HasSuffix(req.URL.Path, "/") && !strings.HasSuffix(newPath, "/") {
+			newPath += "/"
+		}
+	}
+
+	req.URL.Path = newPath
+	req.URL.RawPath = req.URL.EscapedPath()
+	req.RequestURI = req.URL.RequestURI()
+
+	if u.hostname != nil {
+		req.Host = *u.hostname
+	}
+
+	u.next.ServeHTTP(rw, req)
+}