Skip to content



Handlers are advanced topic which may require basic or deeper knowledge of Python language

NOC Plugin ecosystem bases on Handlers - the Python functions which allow to customize NOC behavior. NOC offers a lot of hooks where the custom code can be injected to alter default behaviour. Refer to Handlers Overview for possible handlers and examples

Naming Conventions

Handler is mere a string like:


Prefix noc means handler refers to one of NOCs modules (either builtin, pyRule or Custom). It's possible to use other prefixes, say for third-party python modules not integrated to NOC directly. MyFilter3 is the function (or other callable) name in python module noc.custom.config.filters.


Built-in handlers are provided along with NOC distribution. i.e. refers to function oper_up in file:

<NOC root>
+-> fm
  +-> handlers
      +-> event

Built-in handlers usually used in event and alarm classes.


Custom handlers are attached to NOC with custom repo. Custom handlers are distinguished by noc.custom prefix. i.e. noc.custom.handlers.config.filters.MyFilter refers to functionMyFilter` from file:

<NOC custom root>
+-> handlers
    +-> config

You need to deploy custom repo in order to use custom handlers.


PyRules are custom Python modules stored in NOC database. PyRule handlers are distinguished by noc.pyrules prefix. i.e noc.pyrules.config.filters.MyPyRuleFilter refers to MyPyRuleFilter function from PyRule named config.filters