Changes service name validation logic to ignore any environment variables first.

helper/args/args.go

@@ -21,3 +21,8 @@ func ReplaceEnv(arg string, environments ...map[string]string) string {
 		return arg
 	})
 }
+
+// ReplaceEnvWithPlaceHolder replaces all occurrences of environment variables with the placeholder string.
+func ReplaceEnvWithPlaceHolder(arg string, placeholder string) string {
+	return envRe.ReplaceAllString(arg, placeholder)
+}

nomad/structs/structs.go

@@ -3074,13 +3074,12 @@ func (s *Service) Validate() error {
 	var mErr multierror.Error
 
 	// Ensure the service name is valid per the below RFCs but make an exception
-	// for our interpolation syntax
-	// RFC-952 §1 (https://tools.ietf.org/html/rfc952), RFC-1123 §2.1
-	// (https://tools.ietf.org/html/rfc1123), and RFC-2782
-	// (https://tools.ietf.org/html/rfc2782).
-	re := regexp.MustCompile(`^(?i:[a-z0-9]|[a-z0-9\$][a-zA-Z0-9\-\$\{\}\_\.]*[a-z0-9\}])$`)
-	if !re.MatchString(s.Name) {
-		mErr.Errors = append(mErr.Errors, fmt.Errorf("service name must be valid per RFC 1123 and can contain only alphanumeric characters or dashes: %q", s.Name))
+	// for our interpolation syntax by first stripping any environment variables from the name
+
+	serviceNameStripped := args.ReplaceEnvWithPlaceHolder(s.Name, "ENV-VAR")
+
+	if err := s.ValidateName(serviceNameStripped); err != nil {
+		mErr.Errors = append(mErr.Errors, err)
 	}
 
 	switch s.AddressMode {

nomad/structs/structs_test.go

@@ -1681,6 +1681,14 @@ func TestInvalidServiceCheck(t *testing.T) {
 		t.Fatalf("Service should be valid: %v", err)
 	}
 
+	s = Service{
+		Name:      "my_service-${NOMAD_META_FOO}",
+		PortLabel: "bar",
+	}
+	if err := s.Validate(); err == nil {
+		t.Fatalf("Service should be invalid (contains underscore but not in a variable name): %v", err)
+	}
+
 	s = Service{
 		Name:      "abcdef0123456789-abcdef0123456789-abcdef0123456789-abcdef0123456",
 		PortLabel: "bar",