Python-script every time you want to read a value with the C<exec plugin> (see
L<collectd-exec(5)>) and provides a lot more functionality, too.
-The minimum required Python version is I<2.3>.
+The minimum required Python version is I<2.6>.
=head1 CONFIGURATION
=item B<Encoding> I<Name>
The default encoding for Unicode objects you pass to collectd. If you omit this
-option it will default to B<ascii> on I<Python 2> and B<utf-8> on I<Python 3>.
-This is hardcoded in Python and will ignore everything else, including your
-locale.
+option it will default to B<ascii> on I<Python 2>. On I<Python 3> it will
+always be B<utf-8>, as this function was removed, so this will be silently
+ignored.
+These defaults are hardcoded in Python and will ignore everything else,
+including your locale.
=item B<ModulePath> I<Name>
-Appends I<Name> to B<sys.path>. You won't be able to import any scripts you
+Prepends I<Name> to B<sys.path>. You won't be able to import any scripts you
wrote unless they are located in one of the directories in this list. Please
note that it only has effect on plugins loaded after this option. You can
use multiple B<ModulePath> lines to add more than one directory.
If a Python script throws an exception it will be logged by collectd with the
name of the exception and the message. If you set this option to true it will
also log the full stacktrace just like the default output of an interactive
-Python interpreter. This should probably be set to false most of the time but
-is very useful for development and debugging of new modules.
+Python interpreter. This does not apply to the CollectError exception, which
+will never log a stacktrace.
+This should probably be set to false most of the time but is very useful for
+development and debugging of new modules.
=item B<Interactive> I<bool>
=item *
-B<2.> collectd will block I<SIGINT>. Pressing I<Ctrl+C> will usually cause
+B<2.> Python will be handling I<SIGINT>. Pressing I<Ctrl+C> will usually cause
collectd to shut down. This would be problematic in an interactive session,
-therefore this signal will be blocked. You can still use it to interrupt
-syscalls like sleep and pause but it won't generate a I<KeyboardInterrupt>
-exception either.
+therefore Python will be handling it in interactive sessions. This allows you
+to use I<Ctrl+C> to interrupt Python code without killing collectd. This also
+means you can catch I<KeyboardInterrupt> exceptions which does not work during
+normal operation.
To quit collectd send I<EOF> (press I<Ctrl+D> at the beginning of a new line).
The following complex types are used to pass values between the Python plugin
and collectd:
+=head2 CollectdError
+
+This is an exception. If any Python script raises this exception it will
+still be treated like an error by collectd but it will be logged as a
+warning instead of an error and it will never generate a stacktrace.
+
+ class CollectdError(Exception)
+
+Basic exception for collectd Python scripts.
+Throwing this exception will not cause a stacktrace to be logged, even if
+LogTraces is enabled in the config.
+
=head2 Signed
The Signed class is just a long. It has all its methods and behaves exactly
=over 4
-=item B<dispatch>([type][, values][, plugin_instance][, type_instance][, plugin][, host][, time][, interval]) -> None. Dispatch a value list.
+=item B<dispatch>([type][, message][, plugin_instance][, type_instance][, plugin][, host][, time][, severity][, meta]) -> None. Dispatch a notification.
Dispatch this instance to the collectd process. The object has members for each
of the possible arguments for this method. For a detailed explanation of these
The severity of this notification. Assign or compare to I<NOTIF_FAILURE>,
I<NOTIF_WARNING> or I<NOTIF_OKAY>.
+=item meta
+
+These are the meta data for the Notification object.
+It has to be a dictionary of numbers, strings or bools. All keys must be
+strings. I<int> and I<long> objects will be dispatched as signed integers unless
+they are between 2**63 and 2**64-1, which will result in a unsigned integer.
+One of these storage classes can be forced by using the classes
+B<collectd.Signed> and B<collectd.Unsigned>. A meta object received by a
+notification callback will always contain B<Signed> or B<Unsigned> objects.
+
=back
=head1 FUNCTIONS
The callback will be called without arguments.
-=item register_read(callback[, interval][, data][, name]) -> identifier
+=item register_read(callback[, interval][, data][, name]) -> I<identifier>
This function takes an additional parameter: I<interval>. It specifies the
time between calls to the callback function.
or a callback function. The identifier will be constructed in the same way as
for the register functions.
+=item B<get_dataset>(I<name>) -> I<definition>
+
+Returns the definition of a dataset specified by I<name>. I<definition> is a list
+of tuples, each representing one data source. Each tuple has 4 values:
+
+=over 4
+
+=item name
+
+A string, the name of the data source.
+
+=item type
+
+A string that is equal to either of the variables B<DS_TYPE_COUNTER>,
+B<DS_TYPE_GAUGE>, B<DS_TYPE_DERIVE> or B<DS_TYPE_ABSOLUTE>.
+
+=item min
+
+A float or None, the minimum value.
+
+=item max
+
+A float or None, the maximum value.
+
+=back
+
=item B<flush>(I<plugin[, timeout][, identifier]) -> None
Flush one or all plugins. I<timeout> and the specified I<identifiers> are
A very simple read function might look like:
+ import random
+
def read(data=None):
vl = collectd.Values(type='gauge')
vl.plugin='python.spam'
To register those functions with collectd:
- collectd.register_read(read);
- collectd.register_write(write);
+ collectd.register_read(read)
+ collectd.register_write(write)
See the section L<"CLASSES"> above for a complete documentation of the data
types used by the read, write and match functions.
-=head1 NOTES
-
-=over 4
-
-=item *
-
-Please feel free to send in new plugins to collectd's mailing list at
-E<lt>collectdE<nbsp>atE<nbsp>verplant.orgE<gt> for review and, possibly,
-inclusion in the main distribution. In the latter case, we will take care of
-keeping the plugin up to date and adapting it to new versions of collectd.
-
-Before submitting your plugin, please take a look at
-L<http://collectd.org/dev-info.shtml>.
-
-=back
-
=head1 CAVEATS
=over 4
=item *
Not all aspects of the collectd API are accessible from Python. This includes
-but is not limited to filters and data sets.
+but is not limited to filters.
=back
This manpage has been written by Sven Trenkel
E<lt>collectdE<nbsp>atE<nbsp>semidefinite.deE<gt>.
It is based on the L<collectd-perl(5)> manual page by
-Florian Forster E<lt>octoE<nbsp>atE<nbsp>verplant.orgE<gt> and
+Florian Forster E<lt>octoE<nbsp>atE<nbsp>collectd.orgE<gt> and
Sebastian Harl E<lt>shE<nbsp>atE<nbsp>tokkee.orgE<gt>.
=cut
projects / collectd.git / blobdiff