zenpacklib is a single Python module designed to be packaged with every ZenPack. There is a single file, zenpacklib.py that must be distributed with each ZenPack.
Be sure that you have a good Development Environment setup before proceeding.
All commands in this section should be run as the zenoss user on the host
unless otherwise noted. If you don’t login to the host as the zenoss user,
su - zenoss to get a login shell.
Depending on what versions of Zenoss your ZenPack is supporting you may need to get a specific version of zenpacklib. See Compatibility for more information. Since the latest version of zenpacklib is usually compatible with recent versions of Zenoss it’s usually safe to get the most recent release. This can be done with the following commands.
su - zenoss cd /z wget http://zenpacklib.zenoss.com/zenpacklib.py chmod 755 zenpacklib.py
Executing zenpacklib.py requires a live Zenoss environment. Always executing it as the zenoss user in your Zope container is a good way to have the right environment setup. The following commands show how to do this.
serviced service attach zope # attach to zope container su - zenoss # become zenoss user in zope container /z/zenpacklib.py version exit # back to root in container exit # back to host
These five commands can be reduced to the following single command if you setup
the helper aliases and functions your
.bashrc recommended in
Helper Aliases and Functions.
Creating a ZenPack¶
There are two ways to get started with zenpacklib. You can either use it to create a new ZenPack from the command line, or you can copy it into an existing ZenPack. We’ll start by creating a ZenPack from the command line.
Run the following commands to create a new ZenPack.
# Create ZenPacks in /z so the host and containers can access them. cd /z zenpacklib create ZenPacks.acme.Widgeter
This will print several lines to let you know what has been created. Note that the ZenPack’s source directory has been created, but it has not yet been installed.
Creating source directory for ZenPacks.acme.Widgeter: - making directory: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter - creating file: ZenPacks.acme.Widgeter/setup.py - creating file: ZenPacks.acme.Widgeter/MANIFEST.in - creating file: ZenPacks.acme.Widgeter/ZenPacks/__init__.py - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/__init__.py - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/__init__.py - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/zenpack.yaml - copying: ./zenpacklib.py to ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter
Now let’s take a look at zenpack.yaml. This is the file that will define what our ZenPack does.
Let’s add a device class and a monitoring template to our ZenPack. Change zenpack.yaml to contain the following:
name: ZenPacks.acme.Widgeter device_classes: /Server/ACME/Widgeter: zProperties: zDeviceTemplates: - WidgeterHealth templates: WidgeterHealth: description: ACME Widgeter monitoring. datasources: health: type: COMMAND parser: Nagios commandTemplate: "echo OK|percent=100" datapoints: percent: rrdtype: GAUGE rrdmin: 0 rrdmax: 100 thresholds: unhealthy: dsnames: [health_percent] eventClass: /Status severity: Warning minval: 90 graphs: Health: units: percent miny: 0 maxy: 0 graphpoints: Health: dpName: health_percent format: "%7.2lf%%"
Check for Correctness¶
Now that we have a more interesting zenpack.yaml, let’s have zenpacklib check that it’s correct. This can be done using the lint command.
zenpacklib lint ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/zenpack.yaml
Lint will print information about errors it finds in the YAML file. If nothing is printed, lint thinks the YAML is correct.
Installing a ZenPack¶
Now that we’ve created a ZenPack called ZenPacks.acme.Widgeter in /z, we can install it into our Zenoss system by running the following command.
z zenpack --link --install ZenPacks.acme.Widgeter
Zenoss must be restarted anytime a new ZenPack is installed. A full restart of the entire system can be performed by running one of the following command.
serviced service restart Zenoss.core serviced service restart Zenoss.resmgr
Technically it isn’t necessary to restart everything. A lot of the infrastructure services don’t use ZenPack code. The following is a smaller list of services that you’re likely to need to restart after installing and modifying ZenPacks during development.
The following command will quickly restart just these services.
echo Zope zenhub zeneventd zenactiond zenjobs | xargs -n1 serviced service restart