alerta-blackout-regex
Alerta plugin to enhance the blackout management, by matching the alerts against blackouts with PCRE (Perl Compatible Regular Expression) on attributes.
A blackout is considered matched when all its attributes are matched.
Once an alert is identified as matching a blackout, a special label is applied,
with the format: regex_blackout=<blackout id>, where blackout id is the
ID of the matched blackout, e.g.,
regex_blackout=d8ba1d3b-dbfd-4677-ab00-e7f8469d7ad3. This way, when the
alert is fired again, there's no need to verify the matching again, but simply
verify whether the blackout referenced is still active.
Important
Beginning with version 2.0.0, the behaviour has changed, and instead of evaluating the alert into the post_receive hook, this plugin now evaluates the alerts through the pre_receive hook. The reasoning was that post_receive would set the blackout status after the alert has been sent to other plugins, which has resulted in confusing behaviour.
That said, the plugin has been changed to process the alert in
pre_receive and therefore before the alert has been correlated. As the
Blackouts are retrieved from the Alerta API as unfortunately there's no
other way to gather the Blackouts from a plugin via other internal
mechanisms, processing each and every alert throguh pre_receive would put
a lot more workload on your Alerta API. To reduce this, the
blackout_regex plugin now caches the Blackouts locally, into a file. To
fine tune this behaviour for your own setuo you are able to set a few
environment variables. See more details below, under the _Configuration_
section.
Note
Starting with version 3.0.0 onwards, the plugin will gather the list of Blackouts straight from the database (instead of using the API, as previously). This should normally improve reliability, but as there's no caching involved, every alert notification coming in (before being evaluated and correlated) will cause a DB query.
Installation
This plugin is designed to be installed on the Alerta server; the package is available on PyPI so you can install as:
pip install alerta-blackout-regexConfiguration
Add blackout_regex to the list of enabled PLUGINS in alertad.conf server
configuration file and set plugin-specific variables either in the server
configuration file or as environment variables.
PLUGINS = ['blackout_regex']Note
To ensure this plugin won't affect the existing Blackouts you may have in
place, it is recommended to list the blackout_regex plugin after the
native blackout plugin in the PLUGINS configuration option or
environment variable.
References
License
Copyright (c) 2020-2022 Mircea Ulinic. Available under the Apache License 2.0.
