feature(label): tolerate backslash in the label name (#1595) (#2083)

Signed-off-by: Shafreeck Sea <shafreeck@gmail.com>

server/util.go

@@ -296,10 +296,10 @@ func InitHTTPClient(svr *Server) error {
 	return nil
 }
 
-const matchRule = "^[A-Za-z0-9]([-A-Za-z0-9_.]*[A-Za-z0-9])?$"
+const matchRule = "^[A-Za-z0-9]([-A-Za-z0-9_./]*[A-Za-z0-9])?$"
 
 // ValidateLabelString checks the legality of the label string.
-// The valid label consist of alphanumeric characters, '-', '_' or '.',
+// The valid label consists of alphanumeric characters, '-', '_', '.' or '/',
 // and must start and end with an alphanumeric character.
 func ValidateLabelString(s string) error {
 	isValid, _ := regexp.MatchString(matchRule, s)

server/util_test.go

@@ -68,6 +68,9 @@ func (s *testUtilSuite) TestVerifyLabels(c *C) {
 		{"www.pingcap.com", false},
 		{"h_127.0.0.1", false},
 		{"a", false},
+		{"a/b", false},
+		{"ab/", true},
+		{"/ab", true},
 	}
 	for _, t := range tests {
 		c.Assert(ValidateLabelString(t.label) != nil, Equals, t.hasErr)