/* * $Id: README.pycli,v 1.3 2008/08/07 18:25:41 tyreld Exp $ * * README.pycli * * (C) Copyright IBM Corp. 2002, 2008 * * THIS FILE IS PROVIDED UNDER THE TERMS OF THE ECLIPSE PUBLIC LICENSE * ("AGREEMENT"). ANY USE, REPRODUCTION OR DISTRIBUTION OF THIS FILE * CONSTITUTES RECIPIENTS ACCEPTANCE OF THE AGREEMENT. * * You can obtain a current copy of the Eclipse Public License from * http://www.opensource.org/licenses/eclipse-1.0.php * * Author: David Eger <dteger@us.ibm.com>, <eger@cc.gatech.edu> * Contributors: * * Description: Python bindings for WBEMCLI */ The WBEMCLI Python Bindings =========================== In addition to the 'wbemcli' command line tool, this package includes python bindings for accessing CIMOMs such as SNIA-CIMOM or OpenPegasus. If you do not use Python, you can safely ignore this. Files included: + CimXml.py - the low-level C++/Python interface + cimcli.py - some utility functions to make using CimXml easier. To compile the Python bindings, type: $ make clipy Using Python to talk to your CIMOMs =================================== After this, you can run Python scripts which access CIMOMs, or use Python as an interactive shell for talking to CIMOMs. In Python, comments begin with a hash mark (#). The Python prompt is '>>>', or when continuing from a previous line '...'. Python code is block structured by white space. Further, you can continue the current line by putting a slash at the end of your line. Below is a sample of how you can use Python as a shell interface to your CIMOMs: # BEGIN SAMPLE INTERACTION $ python Python 2.2.3+ (#1, Jul 6 2003, 23:35:56) [GCC 3.3.1 20030626 (Debian prerelease)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> execfile("cimcli.py") # import utility functions >>> machines = getCIMOMs("192.168.64.8","24","PING") Portscanning port 5988 on subnet 192.168.64.8/24 for prospective CIMOMs IPs found: ['192.168.64.8', '192.168.64.207'] >>> setmachine("192.168.64.207", locals()) # >>> # tell the CLI which machine we want to talk to >>> FSs = ei("CIM_FileSystem") # >>> # get a list of the filesystems on the box >>> len(FSs) # how many did we get? 4 >>> for i in FSs.ia: # for each filesystem instance... (ia = instance array) ... print i ... CreationClassName="Linux_Ext3FileSystem",Caption="Ext3 local file system",CSCreationClassName="Linux_ComputerSystem",CSName="dyn324513pok.pok.ibm.com",Name="/dev/sda1",Root="/boot",FileSystemType="ext3",Status="OK",Description="Represents the file store controlled by a ComputerSystem through local means.",ReadOnly=FALSE,BlockSize=1024,FileSystemSize=103515136,AvailableSpace=82735104,MaxFileNameLength=255,PercentageSpaceUse=14,ElementName="/boot",EnabledStatus=2,OtherEnabledStatus="NULL",RequestedStatus=2,EnabledDefault=3 CreationClassName="Linux_Ext3FileSystem",Caption="Ext3 local file system",CSCreationClassName="Linux_ComputerSystem",CSName="dyn324513pok.pok.ibm.com",Name="/dev/sda2",Root="/home",FileSystemType="ext3",Status="OK",Description="Represents the file store controlled by a ComputerSystem through local means.",ReadOnly=FALSE,BlockSize=4096,FileSystemSize=7270162432,AvailableSpace=6450884608,MaxFileNameLength=255,PercentageSpaceUse=6,ElementName="/home",EnabledStatus=2,OtherEnabledStatus="NULL",RequestedStatus=2,EnabledDefault=3 CreationClassName="Linux_Ext3FileSystem",Caption="Ext3 local file system",CSCreationClassName="Linux_ComputerSystem",CSName="dyn324513pok.pok.ibm.com",Name="/dev/sdb1",Root="/usr",FileSystemType="ext3",Status="OK",Description="Represents the file store controlled by a ComputerSystem through local means.",ReadOnly=FALSE,BlockSize=4096,FileSystemSize=8427929600,AvailableSpace=6655352832,MaxFileNameLength=255,PercentageSpaceUse=15,ElementName="/usr",EnabledStatus=2,OtherEnabledStatus="NULL",RequestedStatus=2,EnabledDefault=3 CreationClassName="Linux_Ext3FileSystem",Caption="Ext3 local file system",CSCreationClassName="Linux_ComputerSystem",CSName="dyn324513pok.pok.ibm.com",Name="/dev/sda5",Root="/var",FileSystemType="ext3",Status="OK",Description="Represents the file store controlled by a ComputerSystem through local means.",ReadOnly=FALSE,BlockSize=4096,FileSystemSize=1052434432,AvailableSpace=949731328,MaxFileNameLength=255,PercentageSpaceUse=4,ElementName="/var",EnabledStatus=2,OtherEnabledStatus="NULL",RequestedStatus=2,EnabledDefault=3 >>> for i in FSs.ia: # that was too much information, let's do it different now. ... fsprops = i.getProperties() ... print "Filesystem on %s is %d%% full" % \ ... (fsprops["ElementName"], \ ... 100 - 100 * long(fsprops["AvailableSpace"]) / long(fsprops["FileSystemSize"])) ... Filesystem on /boot is 21% full Filesystem on /home is 12% full Filesystem on /usr is 22% full Filesystem on /var is 10% full >>> # END SAMPLE INTERACTION How it works ============ By using the Python Client, you're getting direct access to the C++ objects described by CimXml.h. If, instead of saying "print" above, we had just typed the name of an object, our interaction would look like this: >>> execfile("cimcli.py") >>> setmachine("localhost",locals()) >>> FSs = ei("CIM_FileSystem") >>> FSs <C NamedInstancesXml instance at _1015b4b0_p_NamedInstancesXml> This is the raw C++ object (actually, a raw pointer to a C++ object) of type NamedInstancesXml. If you look in CimXml.h, you'll see a description like: /* from CimXml.h */ class NamedInstancesXml : public RetValXml { public: InstanceArray ia; InstanceNameArray ina; NamedInstancesXml(NamedInstanceXml *n); NamedInstancesXml * clone() { return new NamedInstancesXml(*this);} void add(NamedInstanceXml& n); InstanceNameXml& getName(int n) { return ina.at(n); } InstanceXml& getInst(int n) { return ia.at(n); } int size() { return ina.size(); } }; Python doesn't need to know all of these details, just some. We use a program called SWIG to automatically generate wrapper code so our Python code can talk to our C++ code. We tell SWIG what wrappers to generate with a SWIG interface file called "CimXml.i". In that file, we find the description: /* from CimXml.i */ extern class NamedInstancesXml : public RetValXml { public: InstanceArray ia; InstanceNameArray ina; NamedInstancesXml(NamedInstanceXml *n); void add(NamedInstanceXml& n); InstanceNameXml& getName(int n); InstanceXml& getInst(int n); %rename(__len__) size; int size(); }; We've included the output of SWIG - CimXml.py and CimXml_wrap.cxx, so unless you change the interface file, you don't need to have SWIG. For each piece of code in the interface file, SWIG makes the glue so that handling objects and calling member functions between one OO language and another "just works." If your object has a method called add(), and you tell SWIG this, then you can call object.add() from your Python code just as you would from C++. Sometimes, however, you need to give SWIG some hints. Calling len() on a Python array is a natural way to get the array's length. Since our C++ code has a different name for this, we use the SWIG directive %rename().