feat: add ability to set global properties

Not all properties can be set globally, and the "appName" in the global case is currently defaulted to `--global`. This is okay because domain label names cannot start with hyphens, and all app names must be valid domain label names.

plugins/ps/ps.go

@@ -16,6 +16,9 @@ var (
 	DefaultProperties = map[string]string{
 		"restart-policy": "on-failure:10",
 	}
+
+	// GlobalProperties is a map of all valid global ps properties
+	GlobalProperties = map[string]bool{}
 )
 
 // Rebuild rebuilds app from base image

plugins/ps/subcommands.go

@@ -163,7 +163,7 @@ func CommandSet(appName string, property string, value string) error {
 		return dockeroptions.SetDockerOptionForPhases(appName, []string{"deploy"}, "restart", value)
 	}
 
-	common.CommandPropertySet("ps", appName, property, value, DefaultProperties)
+	common.CommandPropertySet("ps", appName, property, value, DefaultProperties, GlobalProperties)
 	return nil
 }