Getting Started

The first thing we’ll need to do is install the ZenPackLib ZenPack into our development system. This is done in the same way as it would be in any Zenoss system.

The ZenPackLib ZenPack provides the zenpacklib command line tool, which will allow us to create ZenPacks.

This tutorial assumes your system is already setup as described in Development Environment.

Installing ZenPackLib

The latest version of ZenPackLib can be downloaded from its entry in the ZenPack Catalog. Note that you may already have the latest version installed on your system. The following commands show how you would download and install version 2.1.1.

From here on all commands 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, use su - zenoss to get a login shell.

cd /tmp
wget http://wiki.zenoss.org/download/zenpacks/ZenPacks.zenoss.ZenPackLib/2.1.1/ZenPacks.zenoss.ZenPackLib-2.1.1.egg
serviced service run zope zenpack-manager install ZenPacks.zenoss.ZenPackLib-2.1.1.egg

Executing zenpacklib 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 demonstrate how to do this.

serviced service attach zope # attach to zope container
su - zenoss # become zenoss user in zope container
zenpacklib --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 the Helper and Aliases and Functions section of the Development Environment page.

zenpacklib --version

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 update an existing ZenPack to use it. 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/datasources/__init__.py
  - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/thresholds/__init__.py
  - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/parsers/__init__.py
  - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/migrate/__init__.py
  - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/resources/__init__.py
  - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/modeler/__init__.py
  - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/tests/__init__.py
  - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/libexec/__init__.py
  - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/modeler/plugins/__init__.py
  - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/lib/__init__.py
  - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/__init__.py
  - creating file: ZenPacks.acme.Widgeter/ZenPacks/acme/Widgeter/zenpack.yaml

Now let’s take a look at zenpack.yaml. This is the file that will define a large part of what our ZenPack is.

zenpack.yaml

name: ZenPacks.acme.Widgeter

Add Monitoring

Let’s add a device class and a monitoring template to our ZenPack. Change zenpack.yaml to contain the following:

zenpack.yaml

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 commands depending on what distribution of Zenoss you have installed.

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.

Zope
zenhub
zeneventd
zenactiond
zenjobs

The following command will quickly restart just these services.

echo Zope zenhub zeneventd zenactiond zenjobs | xargs -n1 serviced service restart

What Next?

You can either start with some Tutorials or jump right into the YAML Reference.