Python Web/Grid Services

Presenter: Joshua Boverhof

Lawrence Berkeley National Lab.

Project linksWebpage: http://pywebsvcs.sourceforge.net/ http://dsd.lbl.gov/gtg/projects/download/download_info.html

Demo: http://dsd.lbl.gov/~boverhof

Email: JRBoverhof@lbl.gov Pywebsvcs-talk@lists.sourceforge.net

Overview

ZSI -- Zolera SOAP implementation• wsdl2python -- WSDL/XML Schema• Generate Client: Locators, Ports, Messages• Generate Service: ServiceSOAPBinding

pyGridWare -- WS-Resource Framework• New Directions: Basic Profile, WS-Addressing,

WS-Resource, XML Message Security

WSDL Info Items

WSDL to Python

TypeCodes: Describing the data

• ZSI.TypeCode “aname”: specifies python attribute name TypeCode will access for element value when parsing and serializing.

--wsdl2py convention specify aname as “_name”

• Facets: minOccurs, maxOccurs, nillable

--ZSI TypeCodes expects repeatable (maxOccurs>1) elements to be specified in sequences.

Elements, Types, and TypeCodes

<wsdl:message name='FreeDBService_searchByTrack_Response'> <wsdl:part name='response' element='ns0:ArrayOfCDInfo_Response'/> </wsdl:message>

<xsd:element name="ArrayOfCDInfo_Response” nillable="true” type="xns4:ArrayOfCDInfo"/>

<xsd:complexType name="ArrayOfCDInfo"> <xsd:sequence> <xsd:element maxOccurs="unbounded" minOccurs="0" name="CDInfo" nillable="true" type="tns:CDInfo"/> </xsd:sequence> </xsd:complexType>

<xsd:complexType name="CDInfo"> <xsd:sequence> <xsd:element name="artist" nillable="true” type="xsd:string"/> <xsd:element name="category" nillable="true” type="xsd:string"/> <xsd:element name="discId" nillable="true” type="xsd:string"/> <xsd:element name="title" nillable="true” type="xsd:string"/> </xsd:sequence></xsd:complexType>

WSDL from http://soap.systinet.net/demos/FreeDB/wsdl

Elements --> XML Instance

<e:Envelope xmlns:e="http://schemas.xmlsoap.org/soap/envelope/" xmlns:d="http://www.w3.org/2001/XMLSchema" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:wn0="http://systinet.com/wsdl/com/systinet/demo/freedb/" xmlns:wn1="http://systinet.com/xsd/SchemaTypes/" xmlns:wn2="http://idoox.com/interface"> <e:Body> <wn1:ArrayOfCDInfo_Response i:type="wn0:ArrayOfCDInfo"> <wn0:CDInfo i:type="wn0:CDInfo"> <wn0:artist i:type="d:string">Deftones et Slipknot</wn0:artist> <wn0:category i:type="d:string">rock</wn0:category> <wn0:discId i:type="d:string">23110313</wn0:discId> <wn0:title i:type="d:string">Personnalisé</wn0:title> </wn0:CDInfo> … </e:Body></e:Envelope>

Generated Client Modules

_services.py _types.py

%wsdl2py -u http://soap.systinet.net/demos/FreeDB/wsdl%python>>>from com_systinet_demo_freedb_FreeDBService_services import *>>>loc = JavaServiceLocator()>>>port = loc.getFreeDBService()>>>msg = port.searchByArtist(’Slipknot')>>> msg<com_systinet_demo_freedb_FreeDBService_services_types.ArrayOfCDInfo_Response_Dec>>>> len(msg._CDInfo)74>>> msg._CDInfo[49]._titleu'My Plague (New Abuse Mix)'

Generated Service Module

_types.py

%wsdl2dispatch -u http://soap.systinet.net/demos/FreeDB/wsdl%python>>>from com_systinet_demo_freedb_FreeDBService_services_server import *>>>from ZSI.ServiceContainer import AsServer>>>AsServer(port=8080,services=(com_systinet_demo_freedb_FreeDBService(),))

_services.py_services_server.py

Service Module class com_systinet_demo_freedb_FreeDBService(ServiceSOAPBinding): soapAction = { 'http://systinet.com/wsdl/com/systinet/demo/freedb/FreeDBService#getDetails#':'soap_getDetails', 'http://systinet.com/wsdl/com/systinet/demo/freedb/FreeDBService#search#':'soap_search', 'http://systinet.com/wsdl/com/systinet/demo/freedb/FreeDBService#searchByArtist#':'soap_searchByArtist', 'http://systinet.com/wsdl/com/systinet/demo/freedb/FreeDBService#searchByTitle#':'soap_searchByTitle', 'http://systinet.com/wsdl/com/systinet/demo/freedb/FreeDBService#searchByTrack#':'soap_searchByTrack', }

def __init__(self, post='/FreeDB/', **kw): ServiceSOAPBinding.__init__(self, post)

def soap_searchByArtist(self, ps): # input vals in request object args = ps.Parse( FreeDBService_searchByArtist_1_Request() )

# assign return values to response object response = FreeDBService_searchByArtist_Response() #User Adds some logic to do something if args == ‘Slipknot’: class Holder: pass response._CDInfo = [Holder()] response._CDInfo[0]._title = 'My Plague (New Abuse Mix) ' response._CDInfo[0]._artist = ’SLIPKNOT' return response

New Directions: pyGridWare

• WS-Resource: Stateless web services paradigm, implied factory pattern.

• WS-Address: Specify resource identity in SOAP Header.

• Message-Level Security

Implied Resource Pattern

clientSoap:Header ServiceBody

1

23

45

Model State

Client for WS-Resource

$wsdl2py -f counter_service.wsdl -a

•Client generated in same way… Just specify WS-Addressing•Create operation -- receives an EndpointReference containing a resource ID. This is used to refer back to the stateful instance.•Drop EndpointReference into a new port.•New port refers to a stateful service

Create XML Instance

<SOAP-ENV:Envelope xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ZSI="http://www.zolera.com/schemas/ZSI/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">

<SOAP-ENV:Header xmlns:ns1="http://schemas.xmlsoap.org/ws/2003/03/addressing"> <ns1:MessageID id="567080">uuid:1087253160.24</ns1:MessageID> <ns1:Action id="54e808">http://counter.com/service/CounterPortType/createCounterRequest</ns1:Action> <ns1:To id="73338">http://bundy.localdomain:8080/wsrf/services/CounterService</ns1:To> </SOAP-ENV:Header>

<SOAP-ENV:Body xmlns:ns1="http://counter.com"> <ns1:createCounter></ns1:createCounter></SOAP-ENV:Body>

</SOAP-ENV:Envelope>

%python>>>import pyGridWare.generated.stubs.Counter_services as COUNTER>>>locator = COUNTER.CounterServiceLocator()>>>port = locator.getCounterPortType()>>>msg = port.createCounter(COUNTER.CreateCounterRequest())

Create Response XML Instance<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:wsa="http://schemas.xmlsoap.org/ws/2003/03/addressing"> <soapenv:Header> <wsa:MessageID soapenv:mustUnderstand="0">uuid:E77B0490-BE5B-11D8-92A0</wsa:MessageID> <wsa:To soapenv:mustUnderstand="0">http://schemas.xmlsoap.org/ws/2003/03/addressing/role/anonymous</wsa:To> <wsa:Action soapenv:mustUnderstand="0">http://counter.com/service/CounterPortType/createCounterResponse </wsa:Action><wsa:From><wsa:Address>http://bundy.localdomain:8080/wsrf/services/CounterService</wsa:Address></wsa:From> <ns0:RelatesTo RelationshipType="wsa:Response" soapenv:mustUnderstand="0" xmlns:ns0="http://schemas.xmlsoap.org/ws/2003/03/addressing">uuid:1087255976.97</ns0:RelatesTo> </soapenv:Header>

<soapenv:Body> <createCounterResponse xmlns="http://counter.com"> <wsa:EndpointReference> <wsa:Address>http://bundy.localdomain:8080/wsrf/services/CounterService</wsa:Address> <wsa:ReferenceProperties> <CounterKey>27378735</CounterKey> </wsa:ReferenceProperties> </wsa:EndpointReference> </createCounterResponse> </soapenv:Body></soapenv:Envelope>

Add Operation <SOAP-ENV:Envelope xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ZSI="http://www.zolera.com/schemas/ZSI/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"><SOAP-ENV:Header xmlns:ns1="http://schemas.xmlsoap.org/ws/2003/03/addressing" xmlns:ns2="http://counter.com"> <ns1:MessageID id="740980">uuid:1088447466.12</ns1:MessageID> <ns1:Action id="55b610">http://counter.com/service/CounterPortType/addRequest</ns1:Action> <ns1:To id="107a260">http://bundy.localdomain:8080/wsrf/services/CounterService</ns1:To> <ns2:CounterKey id="107a6b0">12399227</ns2:CounterKey></SOAP-ENV:Header><SOAP-ENV:Body xmlns:ns1="http://counter.com"> <ns1:add id="18085d0">11</ns1:add></SOAP-ENV:Body></SOAP-ENV:Envelope>

>>>msg = port.createCounter(COUNTER.CreateCounterRequest())>>>port = locator.getCounterPortType(endPointReference=msg._EndpointReference)>>>msg = port.add(11)