ZenPacks Basics

• ZenPack = packaged Python egg (can be unzipped)

• Name: by convention= ZenPacks.<organization>.<function>

  • It’s possible to have more than three segments.
  • ZenPack names must be unique

• ZenPack Metadata

  • Version
  • Author
  • License
  • Dependencies

Folder hierarchy Root

Path	Contains
/	Object class definitions
/build	Created when ZenPack is exported to an egg file. Can be deleted.
/dist	Created when ZenPack is exported to an egg file. Can be deleted.
/ZenPacks.<organization>.<function>	Base folder of ZenPack
setup.py	Contains parameters for use by setuptools and distutils in creating eggs (name, author, prerequisites, license, …).

Folder hierarchy Base (under ZenPacks.<organization>.<function>)

A __init__.py file must be present in each folder and sub-folder, even if empty. It is recommended to remove the unwanted sample files, created together with the ZenPack.

Path	Contains
__init__.py	Code executed when ZenPack is loaded
analytics.py	Integration with Service Dynamics Analytics
configure.zxml	Glue to link info & interface classes with GUI code
dynamicview.py	Integration with Service Dynamics Dynamic Views
events.py	Integration with Service Dynamics Impact
ExampleComponent.py	Sample code for a new Component
ExampleDevice.py	Sample code for a new Device
info.py	Mapping between object attributes and interface classes for GUI
interfaces.py	Definition of attributes to show in GUI
LICENSE.txt	License text
zenexample.py	Sample code for daemon
/bin	Binaries created by the ZenPack
/browser	GUI definitions
/daemons	Daemons
/datasources	Datasources
/lib	3rd party modules, ZenPack depends on
/libexec	scripts and binaries used by the ZenPack
/migrate	Migrating code between Zenoss versions
/modeler/plugins	Modeler plugins for object classes
/objects	Database objects (device classes, templates, …) added via GUI
/parsers	Command parsers
/reports	Report plugins
/services	Configuration services for custom daemons
/tests	Test scripts
/zep	Custom triggers, notifications and event fields

Export

• Export ZenPack to a different system, generate an egg file

• Create object/object.xml

• During Export, all objects under “ZenPack Provides” are written to objects/objects.xml This implies that if changes are made within those items, the ZenPack must be exported in order to include those changes in the egg file.

• The egg file is found in $ZENHOME/exports

• Export:

  • ADVANCED -> Settings -> ZenPacks -> Action (Bottom-left) -> Export ZenPack

• A command-line can also create the egg file, however it doesn’t generate the objects.xml file:

  cd /z/ZenPacks.community.dummy python setup.py bdist_egg

  The egg file is then found in $ZENHOME/dist

Install

• zenpack –install <ZenPackName>
• Safe (if elements have been added): zenoss restart
• Quick (if elements have been changed): zenhub restart & zopectl restart (zenwebserver restart)

setuptools

• Zenoss provides zenpacksupport, subclass of setuptools
• zenpacksupport defines additional metadata in eggs
  • compatZenossVers: required Zenoss version
  • preZenPackName: non-egg ZenPack that is to be replaced

Configuration, performance and event data

• Configuration data:

  • polled every 12 hours,
  • stored in ZODB,
  • definitions in modeler plugins
  • polled by zenmodeler, using modeler plugins (collector plugins)

• Performance data:

  • polled every 5 minutes,
  • stored in RRD files $ZENHOME/perf/Devices/<Device>/<Component>/<datasource>_<datapoint>.rrd
  • specifications in templates (contains datasources and datapoints definitions)

  • performed by daemons:

    • zenperfsnmp for SNMP data
    • zencommand for SSH data
    • zenpython
    • zenprocess for discovered processes

• Event data

  • 6 tables: status (active events), history, log, detail, heartbeat & alert_status

ZODB

• Zope Object Database

• Zenoss, based on Zope Web Application Server

• Store Python objects and their states (object-oriented database)

• Store information pushed by modeler plugins

• ZEO, layer between Zope and ZODB, allows multiple Zope Servers

• ZMI (Zope Management Interface) http://<zenoss server>:8080/zport/dmd/manage

• Top level = zport/dmd

  • dmd = Device Management Database

• http://docs.zope.org/zope2/zope2book/index.html