Zenoss: Custom XML Export

__init__.py

# It is expected that the following code would be placed in the
# __init__.py of your ZenPack.

# lxml provides an API for building XML documents.
# http://lxml.de/tutorial.html#the-e-factory
from lxml import etree
from lxml.builder import E

# monkeypatch allows us to add a new method (myXML) to an existing
# object (ZentinelPortal a.k.a. /zport).
from Products.ZenUtils.Utils import monkeypatch

# getFacade allows access to the high-level Zenoss Python API.
from Products.Zuul import getFacade


@monkeypatch('Products.ZenModel.ZentinelPortal.ZentinelPortal')
def myXML(self, service_uid=None):
    """Return XML.

    Example service_uid:

        /zport/dmd/DynamicServices/Tenants/ACME/services/ACME

    It is expected that this method be called via an HTTP GET to a URL
    like the following:

        http://myzenoss:8080/zport/myXML?service_uid=/zport/dmd/DynamicServices/Tenants/ACME/services/ACME

    Assumes a nested service structure something like the following:

        ACME
        |
        +-- ACME-Org1
        |   |
        |   +-- ACME-Org1-VDC1
        |   |   |
        |   |   +-- VM1
        |   |   +-- VM2
        |   |
        |   +-- ACME-Org1-VDC2
        |
        +-- ACME-Org2
            |
            +-- ACME-Org2-VDC1

    Returns an XML document something like the following:

        <?xml version='1.0' encoding='utf-8'?>
        <service availability="UP" name="ACME" performance="ACCEPTABLE">
            <subservices>
                <service availability="UP" name="ACME-Org1" performance="ACCEPTABLE">
                    <subservices>
                        <service availability="UP" name="ACME-Org1-VDC2" performance="ACCEPTABLE">
                            <subservices/>
                            <vms/>
                        </service>
                        <service availability="UP" name="ACME-Org1-VDC1" performance="ACCEPTABLE">
                            <subservices/>
                            <vms>
                                <vm availability="UP" memory="1073741824" name="app-server-a" osType="CentOS 4/5/6 (64-bit)" performance="ACCEPTABLE" storage="9562423296" vcpus="1"/>
                                <vm availability="UP" memory="536870912" name="web-server-a" osType="CentOS 4/5/6 (64-bit)" performance="ACCEPTABLE" storage="9561972736" vcpus="1"/>
                            </vms>
                        </service>
                    </subservices>
                    <vms/>
                </service>
            </subservices>
            <vms/>
        </service>

    """
    if not service_uid:
        return xml_string(xml_error("missing 'service_uid' request parameter"))

    return etree.tostring(
        xml_for_service(service_uid),
        encoding='utf-8',
        xml_declaration=True)


def xml_for_service(service_uid):
    """Return XML for service_uid."""

    # Get a handle to the Impact (enterpriseservices) facade.
    impact = getFacade('enterpriseservices')

    # Get info for the specified service.
    try:
        service_info = impact.getInfo(service_uid)
    except Exception as e:
        return xml_error(str(e))

    # Start XML document with top-level service information.
    subservices = E.subservices()
    vms = E.vms()

    xml = E.service(
        subservices,
        vms,
        name=service_info.name,
        availability=service_info.availability(),
        performance=service_info.performance())

    # Get dependencies for the specified service.
    service_dependencies = impact.getDependencies(service_uid)
    for service_dependency in service_dependencies:
        if service_dependency.type == 'DynamicService':
            subservices.append(xml_for_service(service_dependency.url))
        elif service_dependency.type == 'vSphereVirtualMachine':
            vms.append(xml_for_vm(service_dependency))

    return xml


def xml_for_vm(service_dependency):
    """Return XML for VM service_dependency."""
    device_facade = getFacade('device')
    vm = device_facade.getInfo(service_dependency.url)

    return E.vm(
        name=vm.name,
        availability=service_dependency.state['AVAILABILITY'],
        performance=service_dependency.state['PERFORMANCE'],
        vcpus=str(vm.numCPU),
        memory=str(vm.memory),
        storage=str(vm.storageUncommitted),
        osType=vm.osType)


def xml_string(xml):
    """Return a string representation of xml object."""
    return etree.tostring(xml, encoding='utf-8', xml_declaration=True)


def xml_error(message):
    """Return XML string with error message."""
    return E.error(E.message(message))