session 1: the soap story

The SOAP Story

Martin ParryDeveloper & Platform GroupMicrosoft [email protected] http://martinparry.com

mailto:[email protected]

http://martinparry.com/

Agenda

DefinitionsSOAP through the agesSOAP and “standards”Approaches to building and using servicesSOAP Services with WCFServices and the Workflow Foundation

Definitions

SOAP Initially: Simple Object Access ProtocolIt’s about services that exchange messagesThe messages are formed from XMLEach message has headers plus a body

WSDLDescribes services and their operationsUses XML and schema to describe messages

SOAP on the Microsoft Platform

SOAP ToolkitNT4, Windows 2000IIS4 or IIS5Based around COMUsed ISAPI filterNo longer in mainstream supportExtended support expires in March 2008


SOAP MonikerIntroduced in Windows XP ProfessionalScriptable mechanism for invoking web servicesExample vbscript...

Dim proxySet proxy = GetObject(“soap:wsdl=http://....”)


.NET RemotingSupports TCP and HTTP transportsCan use IIS, or notSupports SOAP formatting, or binarySignificant difference: -

– Distributed Object programming paradigm– As opposed to message passing


ASP.NET.asmx web services“add web reference”Still relies on IISSupport in v2.0 for WS-I Basic ProfileNo other “standards” support is built-in


Web Services EnhancementsNow in v3.0Adds support for some WS-* protocolsAllows non-IIS servicesAllows non-HTTP transport


Windows Communication FoundationIntroduced in .NET FX 3.0Entirely new communications APIAllows for changes in transports and protocolsVery extensibleCan use IIS, or notCan use HTTP, or not

– Ships with named pipes, TCP, MSMQ, P2P

“Standards”

WS-SecurityMessage-level security

WS-SecureConversationOptimisation for WS-Security

WS-PolicyContractual info not contained in WSDL

WS-SecurityPolicyPolicy rules that are specific to security

WS-TrustDefines STS

Approaches – Distributed Objects

A long history on the Microsoft platformDCOM, .NET Remoting

Difficulty in managing object lifetimesWisdom of making network transparent?

Perhaps the developer needs to know?

Simple, OO paradigm – easy to code against

Approaches – Message Exchange

Probably still use a proxy classHow is message body formed?

Serialized object graph, orApplication code emits XML content directly

SOAP is all about message exchange reallyJust a question of how this appears to the application developer

Different exchange patternsRequest/response, one-way, duplex, intermediaries

Approaches - SOA

There are multiple definitions of SOANot necessarily tied to web services

A service performs one standalone piece of the business process

Participates in message exchangeNo notion of data + behaviour, as in OOShould use contract + policy so that clients can be built correctlySometimes see “service brokers”

InteropInteropwith otherwith otherplatformsplatforms

ASMX

Attribute- Attribute- BasedBased

ProgrammingProgramming

Enterprise Services

WS-*WS-*ProtocolProtocolSupportSupport

WSE

Message-Message-OrientedOriented

ProgrammingProgramming

System.Messaging

ExtensibilityExtensibilityLocation transparencyLocation transparency

.NET Remoting

Distributed Applications

Services pass messages described by a contractService may provide metadata, describing: -

The contractThe policy applied to communication

“Client”Message

Message

“Service”

Metadata

Message (SOAP)

Headers: Addressing, Security, etc.

Body: Payload

What do I send?

Where do I send it?

How should I send it?

Contract

Address

Binding

Mechanics of Communication

“Service”“Client”

Transport?

Encoding?

Security?

Mechanics of Communication


EndpointContractBindingAddress



Contracts[ServiceContract]

public interface INuggetAccess

{

[OperationContract] string[] GetTopics();

}

.NET Interface

<definitions>

…

<portType>

<operation name=“GetTopics”> …

</portType>

</definitions>

WSDL

svcutil.exe


[ServiceContract]

public interface INuggetAccess

{

[OperationContract] string[] GetTopics();

}

public class NuggetAccessService :

INuggetAccess

{ string[] GetTopics() { }

}

Implements

Consumes

request metadata (WSDL)

Richness of metadata

Service can advertise a lot of info to a client

WSDLWS-Policy (security etc)

Can do so overHTTPWS- MetadataExchange

Makes building “clients” a lot simpler

Service

Contracts

Endpoints

Contract Details

Message exchange might be: -One-way, Request/Response, Two-way (Duplex)

WCF also supports serialization models from .NET 2.0System.Xml.XmlSerialization, System.Runtime.Serialization

[ServiceContract]

public interface INuggetAccess {

[OperationContract] List<TopicInfo> GetTopics();

}

Service

[DataContract(Namespace=…)]

public class TopicInfo {

[DataMember]

public int Id

}

Data

[MessageContract]

public class TypedMessage {

[MessageBody]

[MessageHeader]

}

Message

Hosting Servicespublic class Service :

INuggetAccess

{ string[] GetTopics() { }

}

IIS

<%@ ServiceHost Service=“Service" %>

NuggetAccessService.svc

MyApp.exe

ServiceHost host =

new ServiceHost();

host.Open();

References

ServiceHost is the key class for hostingNeeds manual steps in your host applicationAutomatically done by IIS when provided with a .svc file

IIS handles additional transports in v7.0

Windows Communication Foundation

Client

WCF – sketched architecture

Binding(ordered list of channel types & config)

channel type N

channel type 2

channel type 1config

config

config

Your code

Service

Your code

Met

adat

a

formatting

channel

channel

channel

Transport Channel (HTTP, TCP, MSMQ, Pipes, Peer)

channel

channel

channel

decodingencoding

behaviours behaviours

Standard Framework BindingsPre-built set in the framework

WS-I Basic ProfileWS-* on HTTPTCPNamed PipesMSMQPeer

Configure/code your own as a "custom" binding

Binding

Transactions

Reliability

Security

channels

Configuration

Configuration

Configuration

TransportConfiguration

Instancing, Concurrency, Sessions

Service classes can be instantiated: -Singleton, Per-Call, Per-Session, Shareable

Service code can be either: -Single threaded, Re-entrant or Multi-threaded

Client

Service

Singleton

Message B

Message C

Message A




Client

Service

Single Call

Single Call

Single Call

Message B

Message C

Message A




Client

Service

Per SessionMessage B

Message Asession

Per SessionMessage C

Security in WCF – Out of the box

Transport LevelHTTPSIIS authentication modes

Message LevelUserName, X.509 Certificate, WindowsIssuedToken – that is, federated security

ASP.NET membership and role providers

Security in WCF - Extensibility

Roll your ownUsername validatorToken validatorCredential typesSecurity Token ServiceSAML claimsEtc...

Federated Security with WCF

WCF in .NET FX 3.5

Most of the new stuff isn’t SOAPWe’ll see some of that in the next session

Client proxies and partial trust environmentsDurable servicesComing together with Workflow

Partial Trust

Now possible to call through WCF proxies in a partial trust environmentVarious caveats

Transport is HTTP only, Security is HTTPS onlyEncodings is all except MTOMBindings are BasicHttpBinding, WsHttpBinding, WebHttpBinding*Other limitations

– No Reliable Messaging, Transactions, Secure Conversation

Durable Services

Provider-based framework for easily adding long-running abilities to WCF services

client

Host (e.g. IIS)

implementation

stateresponse + token

initial call

serialize and store

statetoken

Durable Services

Provider-based framework for easily adding long-running abilities to WCF services

client

Host (e.g. IIS)

implementation

state

second call + token

load and deserialize

statetoken

Workflow

WF is not strictly about services, or SOAPIn .NET FX 3.5, WF has some WCF integrationA workflow can consume servicesWe can implement a service as a workflow

Services with WF

Summary

The Microsoft platform has evolved along with SOAP and its accompanying standardsCulminating in WCF

The most flexible, extensible communications stack we’ve ever produced

Additional InformationMSDN Developer Center for Web Services

http://msdn2.microsoft.com/en-gb/webservices/default.aspx

“Standards”http://www.w3.org http://www.ws-i.org http://www.oasis-open.org

SOAhttp://www.opengroup.org/projects/soa http://wiki.oasis-open.org/soa-rm

WCFhttp://netfx3.com/content/WCFHome.aspx

WFhttp://netfx3.com/content/WFHome.aspx

http://msdn2.microsoft.com/en-gb/webservices/default.aspx

http://www.w3.org/

http://www.ws-i.org/

http://www.oasis-open.org/

http://www.opengroup.org/projects/soa

http://wiki.oasis-open.org/soa-rm

MSDN in the UK

Visit http://msdn.co.uk NewsletterEventsScreencastsBlogs

© 2007 Microsoft Ltd. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.

The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the

date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

session 1: the soap story

Technology