1. Notes on WSMAN Client for OpenPegasus
Karl Schopmeyer
25 October 2012

2. Goal
Develop a production WSMAN CIM Client for OpenPegasus that integrates with the existing client infrastructure but provides the WSMan protocol
Integrate to use the existing APIs
Provide lower level WSMAN-only interface for operations and responses.

3. Old WSM on Pegasus prototype
See CVS pegasus_unsupported\wsm
Complete implementation but based on gSOAP soap library. That cannot be used
Need to base on common code in Pegasus/WSMServer (ex. The core wsm objects like selectorset, etc.)
It provides both CIMClient api and CmdLine input with XML responses
It worked but is now 4 years old so pegasus code has changed a lot

4. Client Overview Today Direct call to rep CIMClient.h & CIMClient.cpp
CIMClient.h Operation Request API
Response or exception
CIMClient.h Operation Request API
Direct call to
rep
CIMClient.h & CIMClient.cpp
CIMClient.h & CIMClient.cpp
Create Request Message, confirm link status, check auth, pass to Encoder queue
CIMClientRep
CIMClientRep
CIMOperationRequestEncoder
CIMOperationRequestDecoder
Create XML Message then
HTTP message then
Enqueue hHTTP msg to queue defined in CIMClientRep
HTTPConnection
HTTPConnection
Output to HTTP

5. Client Overview Today NOTE: CIMResponse data is general
CIMClient.h Operation Request API
Response or exception
CIMClient.h Operation Request API
Return
Objects Or
Exceptions
Direct call to
rep
CIMClient.h & CIMClient.cpp
CIMClient.h & CIMClient.cpp
Create Request Message, confirm link status, check auth, pass to Encoder queue
CIMClientRep
CIMClientRep
CIMOperationRequestEncoder
CIMOperationRequestEncoder
Create XML Message then
HTTP message then
Enqueue hHTTP msg to queue defined in CIMClientRep
HTTPConnection
HTTPConnection
Output to HTTP
NOTE: CIMResponse data is general
Wrapper for response data

6. Integrating WSMAN Request side
CIMClient.h API
Decide WS-Man/CIM-XML based on new function
CIMClient
WS-Man CIMClientRep
CIM-XML CIMClientRep
WS-Man encoder
CIM-XML encoder
HTTP Connection
Notes
We should know protocols supported from slp request. Not sure if this is true today.
Only other way is to try one and see if we get back exception or infrastructure support to determine which are supported for a particular server (i.e. try each one).

7. Something like WSMClient.h
Response Side
CIMClient.h API
CIMClient
This is probably where
We take the WS-MAN
Only output
Something like WSMClient.h
WS-Man to
CIMObject Cvtr
CIM_XML CIMClientRep
WS-MAN CIMClientRep
CIM-XML Decoder
WSMAN Decoder
WS-Man should offer an XML based response interface that we can map to XML client or clients
On top of that we cvt these objects to CIMObjects
They are returned just like any other CIM Classes, instances, objects including exceptions. Note that CIMExceptions today are based on the CIM-XML model (DSP0200)
HTTP Connection

8. Integration of Ws-man client
WS-Man will use CIMClient.h api for operation calls.
This means user sees same functions and objects independent of protocol
Add one new call to determine protocol to be used
Base this on JSR 48
See
Don’t expose class with virtual functions. Add wrapper class.

9. JSR 48 Protocol decision calls
static WBEMClient getClient (String protocol)
Get the client object for a particular protocol
static String[] getSupportedProtocols
Get Array of Strings listing all supported protocols
Note that this means a chance to connect possibly.

10. What we want to do With new API
Goals
Determine which protocols exist
Make decision which one to use for a particular connection.
NOTE: We may not want to take the complete object approach that JSR 48 takes so we will probably have somewhat different functions
Possibilities:
Add protocol to CIMClient object creation
Add protocol to connect function
Set Protocol as a new function
In any case we need a way to get list of protocols. That should probably be static since independent of any connection.

11. New Modules in CIMClient Prototype
CIMWSMConverter.*
CIMWSMClientRep*
CIMWSMCommon.*
Issues with current code
Uses gSOAP library
That was our mistake
Uses env variable to select protocol

12. Separate WSMan CLI Clients
Example
pegasus_unsupported\wsm\src\wsm\wsmenum
Defines enum wsm only client
Interface
Wsm/client/WSMClient.h
Creates calls based on WSM params and returns WSM enumerations.
Use wsm/WSMClient/WSMClient.h
Key driver for WSM only interfaces
Need to map WSMClient to Pegasus WSMServer basic objects.
Probably create a new WSMCommon of things that are common to WSMClient and WSMServer
I am not married to separate executable for each function but it is an easy interface that is a level higher than wbemexec.
Need to look at the relationship between CIMWSMEncoder, Decoder, CIMWSMClientRep and WSMClient and probably bring them together.