ZenPackLib's use of automatic class creation requires a bit of explanation.
- Zenoss ZenPack Developement
- Python 2.7
- ZenPackLib familiarity
We assume that you are familiar with ZenPack developement and Python coding. We work from the base of $ZP_DIR. A few things to ensure:
- You have created a DeviceClass for your ZP
- You have set zPythonClass for your DeviceClass to Zenpacks.zenoss.ZP.Class. For example: Zenpacks.zenoss.ControlPlane.ControlPlane
In your class definition (possibly __init__.py) you will have definitions of your Pool classes like:
RELATIONSHIPS_YUML = """
// --------------------------------------------
// Containing Relations
// --------------------------------------------
[ControlPlane]++pools -controlplane[Pool]
// --------------------------------------------
// Non-containing Relations
// --------------------------------------------
[Pool]*parentPool -.-childPools 0..1[Pool]
"""
CFG = zenpacklib.ZenPackSpec(
name=__name__,
zProperties={
'DEFAULTS': {'category': 'Control Plane'},
'zControlPlaneHost': {},
'zControlPlanePort': {'default': '8787'},
},
classes={
'DEFAULTS': {
'base': zenpacklib.Component,
},
'ControlPlane': {
'base': zenpacklib.Device,
'meta_type': 'ZenossControlPlane',
'label': 'Zenoss Control Plane',
},
'Pool': {
'meta_type': 'ZenossControlPlanePool',
'label': 'CP-Pool', # <-- *** Note this label is ZPL magic.
# ZenpackLib: Properties that Auto-magically appear in GUI
'properties': {
'priority': {'label': 'Priority'},
'coreLimit': {'label': 'CPU Core Limit'},
'memoryLimit': {'label': 'Memory Limit'},
},
'relationships': {
# This is required since the pool <=> pool relationship
# can cause recursive ambiguity problems. This breaks that symmetry.
'parentPool': {'label': 'Parent', 'order': 1.0},
'childPools': {'label': 'Children', 'order': 1.1},
}
},
},
class_relationships=zenpacklib.relationships_from_yuml(RELATIONSHIPS_YUML),
)
CFG.create()Things to note:
Pools class is automatically created based on the YAML definition
Go to Advanced->Monitoring Templates: Hit the + at bottom left
The 'relationships' labels are added in order to disambiguate parent-child names. The parent and child name prefix are ZPL magical.
The label attached to Pool is "CP-Pool". It exists to disambiguate the relationship between Item and SubItem objects.
In particular, you will need to.
- Create: a template for each label with the EXACT same name as label.
- Ensure: template is in the appropriate Template Path (/ControlPlane)
Our modeling example has a very simplified version of the ControlPlane ZenPack. The modeler itself grabs a pre-made ObjectMap from the helper class in $ZP_DIR/modeling:
- $ZPDIR/modeler/plugins/zenoss/ControlPlane.py (wrapper for modeling.py)
- $ZPDIR/modeling (Does the heavy lifting)
In the modeler wrapper, ControlPlane.py we have:
import logging
LOG = logging.getLogger('zen.ControlPlane')
from twisted.internet.defer import inlineCallbacks, returnValue
from Products.DataCollector.plugins.CollectorPlugin import PythonPlugin
from ZenPacks.zenoss.ControlPlane import modeling, txcpz
class ControlPlane(PythonPlugin):
"""ControlPlane modeler plugin."""
required_properties = (
'zControlPlaneHost',
'zControlPlanePort',
'zControlPlaneUser',
'zControlPlanePassword',
)
deviceProperties = PythonPlugin.deviceProperties + required_properties
@inlineCallbacks
def collect(self, device, unused):
"""Asynchronously collect data from device. Return a deferred."""
LOG.info("%s: Collecting data", device.id)
# Loop through the required_properties and balk if missing.
for required_property in self.required_properties:
if not getattr(device, required_property, None):
LOG.warn(
"%s: %s not set. Modeling aborted",
device.id,
required_property)
returnValue(None)
client = txcpz.Client(
device.zControlPlaneHost,
device.zControlPlanePort,
device.zControlPlaneUser,
device.zControlPlanePassword)
producer = modeling.DataMapProducer(client)
try:
results = yield producer.getmaps()
except Exception as e:
LOG.exception(
"%s %s ControlPlane error: %s",
device.id, self.name(), e)
returnValue(None)
returnValue(results)
def process(self, device, results, unused):
"""Process results. Return iterable of datamaps or None."""
if results is None:
return None
LOG.info("%s: Processing data", device.id)
results = tuple(results)
return resultsIn the helper class, $ZPDIR/modeling we have (abbreviated to Pools). Notice in line 26, the set_parentPool attribute is processed by ZPL as a ManyToOne relationship between Pools and sub-Pools.
#------------------------------------------------------------------------------
# Zenpacks.zenoss.ControlPlane.modeling
# ControlPlane Modeling: Modeling code for ControlPlane.
#------------------------------------------------------------------------------
from twisted.internet.defer import inlineCallbacks, returnValue
from Products.DataCollector.plugins.DataMaps import RelationshipMap
from .util import get_pool_id, get_host_id, get_service_id, get_running_id
def map_pool(attributes):
"""Return ObjectMap data given attributes.
Example attributes:
{
"Id": "Alternate",
"ParentId": "default",
"Priority": 0,
"CoreLimit": 1,
"MemoryLimit": 1,
}
"""
return {
'id': get_pool_id(attributes['Id']),
'title': attributes['Id'],
'set_parentPool': get_pool_id(attributes['ParentId']),
'priority': attributes['Priority'],
'coreLimit': attributes['CoreLimit'],
'memoryLimit': attributes['MemoryLimit'],
}
class DataMapProducer(object):
"""Produce the DataMap objects required to model """
def __init__(self, client):
self.client = client
@inlineCallbacks
def getmaps(self):
"""Return a datamaps map. """
maps = []
pools = yield self.client.pools()
pool_maps = []
for pool in pools:
pool_map = map_pool(pool)
if pool_map:
pool_maps.append(pool_map)
maps.append(
RelationshipMap(
relname='pools',
modname='ZenPacks.zenoss.ControlPlane.Pool',
objmaps=pool_maps))
returnValue(maps)The datapoints for this model are essentially the dictionary keys of the JSON data sources. That means the datapoints must match the keys exactly.
- Create a Template: the name must matche the label in __init__.py: CP-Pool
- Add a DataSource: The name is arbitrary
- Add a DataPoint to that DataSource: The name must match an attribute (ZPL)
- Some example points:
- Priority
- CoreLimit
- MemoryLimit
| Thu May 29 16:01:30 CDT 2014 |
You can now use the same rendering in the details that are used elsewhere. In your __init__.py you set the renderer property in the class properties section:
classes={ ....
'Flavor': {
'base': 'LogicalComponent',
'meta_type': 'OpenStackFlavor',
'label': 'Flavor',
'order': 1,
'properties': {
'flavorId': { 'grid_display': False }, # 1
'flavorRAM': { 'type_': 'int',
'renderer': 'Zenoss.render.bytesString',
'label': 'RAM' }, # bytes
'flavorDisk': { 'type_': 'int',
'renderer': 'Zenoss.render.bytesString',
'label': 'Disk' } # bytes
}
},
... etc ...
}The ZPL will take care of setting this renderer whereever those variables are used.