safeweb: add Server.Close method (#13160)

Updates https://github.com/tailscale/corp/issues/14881

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>

safeweb/http.go

@@ -300,3 +300,8 @@ func (s *Server) ServeRedirectHTTP(ln net.Listener, fqdn string) error {
 func (s *Server) Serve(ln net.Listener) error {
 	return s.h.Serve(ln)
 }
+
+// Close closes all client connections and stops accepting new ones.
+func (s *Server) Close() error {
+	return s.h.Close()
+}

safeweb/http_test.go

@@ -80,6 +80,7 @@ func TestPostRequestContentTypeValidation(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
+			defer s.Close()
 
 			req := httptest.NewRequest("POST", "/", nil)
 			req.Header.Set("Content-Type", tt.contentType)
@@ -137,6 +138,7 @@ func TestAPIMuxCrossOriginResourceSharingHeaders(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
+			defer s.Close()
 
 			req := httptest.NewRequest(tt.httpMethod, "/", nil)
 			w := httptest.NewRecorder()
@@ -192,6 +194,7 @@ func TestCSRFProtection(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
+			defer s.Close()
 
 			// construct the test request
 			req := httptest.NewRequest("POST", "/", nil)
@@ -267,6 +270,7 @@ func TestContentSecurityPolicyHeader(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
+			defer s.Close()
 
 			req := httptest.NewRequest("GET", "/", nil)
 			w := httptest.NewRecorder()
@@ -307,6 +311,7 @@ func TestCSRFCookieSecureMode(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
+			defer s.Close()
 
 			req := httptest.NewRequest("GET", "/", nil)
 			w := httptest.NewRecorder()
@@ -355,6 +360,7 @@ func TestRefererPolicy(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
+			defer s.Close()
 
 			req := httptest.NewRequest("GET", "/", nil)
 			w := httptest.NewRecorder()
@@ -379,6 +385,7 @@ func TestCSPAllowInlineStyles(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
+			defer s.Close()
 
 			req := httptest.NewRequest("GET", "/", nil)
 			w := httptest.NewRecorder()
@@ -474,6 +481,7 @@ func TestRouting(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
+			defer s.Close()
 
 			req := httptest.NewRequest("GET", tt.requestPath, nil)
 			w := httptest.NewRecorder()