Explicitely mention the fs.inotify.max_user_watches sysctl value.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

In version 0.21, pylint unified all the disable-* (and enable-*)
directives to disable (resp. enable). This leads to a lot of
DeprecationWarning being emitted even if one uses the recommended
version of pylint (0.21.1, as stated in devnotes.rst).

This commit changes all the disable-msg directives to disable.

Signed-off-by: Andrea Spadaccini <spadaccio@google.com>
Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Identified using the “pep8” utility.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

I didn't know why the code previously used
“pyinotify.EventsCodes.ALL_FLAGS” instead of using the flags from
“pyinotify.EventsCodes” directly. Turns out that Pyinotify 0.8 has them
in “pyinotify”, not “pyinotify.EventsCodes”.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

The base class can contain code useful to other inotify users.
As it is “SingleFileEventHandler” can not be used in ganeti-rapi,
therefore it'll use its own small inotify handler class based
on this base class.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Since now we use the SingleFileEventHandler together with an error
handling asyncore dispatcher, we don't need the internal try/except
anymore.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

This mixes AsyncNotifier with GanetiBaseAsyncoreDispatcher to provide an
AsyncNotifier which will log errors, rather than bail out.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

The comments in the SingleFileEventHandler are still confd-specific.
Update them to make them generic for any single-file monitoring.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Cut&Paste, plus the following changes:
  - The class is renamed to SingleFileEventHandler
  - The monitored filename must be passed in and doesn't default to the
    ganeti cluster config file
  - A small docstring is added to the class
  - Pylint disables for except: and method names are added

This makes it possible to write unittests for this class.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Since we contributed AsyncNotifier back to the upstream pyinotify
project, we'll be able, one day, to remove the ganeti version of that
code. For now we still need it to support older distributions, but
having a note about when we'll be able to remove it is nice.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

This patch should have only:

- pylint disables
- docstring changes
- whitespace changes

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Olivier Tharan <olive@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Olivier Tharan <olive@google.com>

On some distributions pyinotify is installed in a different way, and the
actual module just contains an internal pyinotify entry, which is the
actual library. On others the main pyinotify module contains the library
itself. We'll try both, in order to be more compatible.

Signed-off-by: Guido Trotter <ultrotter@google.com>

Found using pylint and epydoc.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

AsyncNotifier is a special asyncore class that delivers inotify events
asynchronously.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>