Merge pull request #3558 from hashicorp/b-nomad-validate-with-defaults

Make validate command ignore environment variables in service name

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

@@ -3074,12 +3074,11 @@ 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) {
+	// 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, fmt.Errorf("service name must be valid per RFC 1123 and can contain only alphanumeric characters or dashes: %q", s.Name))
 	}
 

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",

website/source/docs/job-specification/service.html.md

@@ -89,7 +89,13 @@ does not automatically enable service discovery.
     - `${GROUP}` - the name of the group
     - `${TASK}` - the name of the task
     - `${BASE}` - shorthand for `${JOB}-${GROUP}-${TASK}`
-
+
+    Validation of the name occurs in two parts. When the job is registered, an initial validation pass checks that
+    the service name adheres to RFC-1123 §2.1 and the length limit, excluding any variables requiring interpolation. 
+    Once the client receives the service and all interpretable values are available, the service name will be 
+    interpolated and revalidated. This can cause certain service names to pass validation at submit time but fail 
+    at runtime.
+
 - `port` `(string: <required>)` - Specifies the label of the port on which this
   service is running. Note this is the _label_ of the port and not the port
   number. The port label must match one defined in the [`network`][network]