code: def set_secret_for_plugin(self, secret, plugin=None, mount_path=None):
          
          has_plugin_conf = False
          if plugin is not None:
              has_plugin_conf = self.dj.dock_json_has_plugin_conf(plugin[0],
                                                                  plugin[1])
          if 'secrets' in self.template['spec']['strategy']['customStrategy']:
              if not plugin or has_plugin_conf:
  
                  custom = self.template['spec']['strategy']['customStrategy']
                  if mount_path:
                      secret_path = mount_path
                  else:
                      secret_path = os.path.join(SECRETS_PATH, secret)
  
                  logger.info("Configuring %s secret at %s", secret, secret_path)
                  existing = [secret_mount for secret_mount in custom['secrets']
                              if secret_mount['secretSource']['name'] == secret]
                  if existing:
                      logger.debug("secret %s already set", secret)
                  else:
                      custom['secrets'].append({
                          'secretSource': {
                              'name': secret,
                          },
                          'mountPath': secret_path,
                      })
  
                  # there's no need to set args if no plugin secret specified
                  # this is used in tag_and_push plugin, as it sets secret path
                  # for each registry separately
                  if plugin and plugin[2] is not None:
                      self.dj.dock_json_set_arg(*(plugin + (secret_path,)))
              else:
                  logger.debug("not setting secret for unused plugin %s",
                               plugin[1])
docs: Sets secret for plugin, if no plugin specified
          it will also set general secret
  
          :param secret: str, secret name
          :param plugin: tuple, (plugin type, plugin name, argument name)
          :param mount_path: str, mount path of secret