# patroni.postgresql.callback_executor module

class patroni.postgresql.callback_executor.CallbackAction(*values)

  Bases: `str`, `Enum`

  NOOP = 'noop'
  ON_RELOAD = 'on_reload'
  ON_RESTART = 'on_restart'
  ON_ROLE_CHANGE = 'on_role_change'
  ON_START = 'on_start'
  ON_STOP = 'on_stop'

class patroni.postgresql.callback_executor.CallbackExecutor

  Bases: `CancellableExecutor`, `Thread`

  __init__()

    This constructor should always be called with keyword arguments. Arguments are:

    group should be None; reserved for future extension when a ThreadGroup class is implemented.

    target is the callable object to be invoked by the run() method. Defaults to None, meaning nothing is called.

    name is the thread name. By default, a unique name is constructed of the form “Thread-N” where N is a small decimal number.

    args is a list or tuple of arguments for the target invocation. Defaults to ().

    kwargs is a dictionary of keyword arguments for the target invocation. Defaults to {}.

    If a subclass overrides the constructor, it must make sure to invoke the base class constructor (Thread.__init__()) before doing anything else to the thread.

  call(cmd: List[str]) → None

    Executes one callback at a time.

    Already running command is killed (including child processes). If it couldn’t be killed we wait until it finishes.

    Parameters:

      cmd – command to be executed

  run() → None

    Method representing the thread’s activity.

    You may override this method in a subclass. The standard run() method invokes the callable object passed to the object’s constructor as the target argument, if any, with sequential and keyword arguments taken from the args and kwargs arguments, respectively.

class patroni.postgresql.callback_executor.OnReloadExecutor

  Bases: `CancellableSubprocess`

  call_nowait(cmd: List[str]) → None

    Run one on_reload callback at most.

    To achieve it we always kill already running command including child processes.