zProperties are one part of Zenoss’ hierarchical configuration system. They are configuration properties that can be specified on any device class including the root /Devices class, and on any individual device.
The most-specific value for a zProperty within the hierarchy will be used for any given device. For instance, given a device linux1 in the /Server/Linux device class. The value for zSnmpMonitorIgnore will be checked first on the linux1 device. If it is not set locally on the device, the /Server/Linux device class will then be checked. If not set there, /Server will be checked. Finally the value at / (or /Devices) will be checked as a final resort. Since all zProperties must have a default values that is set at the root device class, there will always be a value for the zProperty. Even if it is an empty string.
To add a zProperty to your ZenPack you must include a zProperties section in your YAML file. The following example shows an example of adding two zProperties.
zProperties: zWidgeterEnable: category: ACME Widgeter type: boolean default: true zWidgeterInterval: category: ACME Widgeter type: string default: 300
Each of these zProperty entries specifies a category, type and default. These are the only valid fields of the a zProperty entry. However, each of these fields has a default value that will be used if the field isn’t explicitly specified. For example, the default value for type is string. So the above example could be shortened slightly by omitting the explicit type on zWidgeterInterval.
zProperties: zWidgeterEnable: category: ACME Widgeter type: boolean default: true zWidgeterInterval: category: ACME Widgeter default: 300
There is a special zProperty entry named DEFAULT that can be used to further shorten definitions in cases where you’re adding many zProperties. The following example shows how DEFAULT can be used to replace the duplicated category property.
zProperties: DEFAULT: category: ACME Widgeter zWidgeterEnable: type: boolean default: true zWidgeterInterval: default: 300
Each zProperty listed in zProperties will be created when the ZenPack is installed, and removed when the ZenPack is removed.
The following fields are valid for a zProperty entry.
Description: Name (e.g. zWidgeterEnable). Must be begin with a lowercase “z”. Required: Yes Type: string Default Value: implied from key in zProperties map
Type of property. Valid types:
Default value for property. Default value depends on the type:
- boolean: false
- lines: 
- password: “” (empty string)
- string: “” (empty string)
- all others: null (None)
Description: Category name. (e.g. ACME Widgeter). Used to group related zProperties in the UI. Required: No Type: string Default Value: “” (empty string)