pyControl Log and Exception

Question

Hi, 
&nbsp; Is there a log file from running pyControl. Where is it located. 
&nbsp; Also, how do you handle exception raised from passing invalid argument (like virtual name that doesn't exist). 
&nbsp; Thanks.

l4l7_53191 · Answer

Hubertus: A nice trick is to pass the 'tracefile' keyword argument when you build the object. For example: 
&nbsp;  
&nbsp; import sys 
&nbsp; import pycontrol.pyControl as pc 
&nbsp; b = pc.BIGIP(hostname = '192.168.1.245', username = 'admin', password = 'admin', wsdl_files = ['System.Statistics'], tracefile = sys.stdout) 
&nbsp;  
&nbsp; ....which will produce a dump of requests/responses to stdout so you can see what is going on (I'm using the iPython shell here): 
&nbsp;  
&nbsp; In [4]: b.System_Statistics.get_version() 
&nbsp; _________________________________ Fri Jun 06 08:18:08 2008 REQUEST: 
&nbsp;  xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" SO 
&nbsp; AP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"&gt; ader&gt; on&gt; 
&nbsp; _________________________________ Fri Jun 06 08:18:09 2008 RESPONSE: 
&nbsp; 200 
&nbsp; OK 
&nbsp; ------- 
&nbsp; Date: Fri, 06 Jun 2008 12:18:08 GMT 
&nbsp; Server: Apache 
&nbsp; Set-Cookie: BIGIPAuthCookie=DD94709528BB1C83D08F3088D4043F4742891F4F; path=/; 
&nbsp; SOAPServer: EasySoap++/0.6 
&nbsp; Transfer-Encoding: chunked 
&nbsp; Content-Type: text/xml; charset="UTF-8" 
&nbsp;  
&nbsp;          xmlns:E="http://schemas.xmlsoap.org/soap/envelope/" 
&nbsp;         xmlns:A="http://schemas.xmlsoap.org/soap/encoding/" 
&nbsp;         xmlns:s="http://www.w3.org/2001/XMLSchema-instance" 
&nbsp;         xmlns:y="http://www.w3.org/2001/XMLSchema" 
&nbsp;         xmlns:iControl="urn:iControl" 
&nbsp;         E:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"&gt; 
&nbsp;  
&nbsp;          xmlns:m="urn:iControl:System/Statistics"&gt; 
&nbsp;          s:type="y:string"&gt;BIG-IP_v9.4.2 
&nbsp;  
&nbsp;  
&nbsp;  
&nbsp;  
&nbsp; Out[4]: {'return': 'BIG-IP_v9.4.2'} 
&nbsp;  
&nbsp; You can also specify a specific log file to dump to if you wish - this isn't limited to sys.stdout (although it's probably the most useful thing for debugging). From time to time you'll get the odd error, which I've forced as an example: 
&nbsp;  
&nbsp; Let's find a getter that wants a specific argument structure, and intentionally pass in a bad value. A handy trick is to print out the special attribute "_h" for the getter method. This will tell you what the input and output params are: 
&nbsp;  
&nbsp; In [8]: print b.System_Statistics.get_virtual_compression_statistics._h 
&nbsp;  
&nbsp; InParams Count: 1 
&nbsp; device_names:           Common.StringSequence 
&nbsp; OutParams Count: 1 
&nbsp; return:         System.Statistics.VirtualCompressionStatistics 
&nbsp;  
&nbsp; So the get_virtual_compression_statistics() method expects an argument of device_names. Passing in a plain old string to this should generate a type mismatch (any parameter that ends in a plural, such as 'device_names' expects a list at a minimum): 
&nbsp;  
&nbsp; In [10]: b.System_Statistics.get_virtual_compression_statistics(device_names = 'hello') 
&nbsp;  
&nbsp; _________________________________ Fri Jun 06 08:22:57 2008 RESPONSE: 
&nbsp; 500 
&nbsp; Internal Server Error 
&nbsp; ------- 
&nbsp; Date: Fri, 06 Jun 2008 12:22:57 GMT 
&nbsp; Server: Apache 
&nbsp; Set-Cookie: BIGIPAuthCookie=DD94709528BB1C83D08F3088D4043F4742891F4F; path=/; 
&nbsp; SOAPServer: EasySoap++/0.6 
&nbsp; Connection: close 
&nbsp; Transfer-Encoding: chunked 
&nbsp; Content-Type: text/xml; charset="UTF-8" 
&nbsp;  
&nbsp;          xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" 
&nbsp;         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
&nbsp;         xmlns:xsd="http://www.w3.org/2001/XMLSchema"&gt; 
&nbsp;  
&nbsp;  
&nbsp;          xsi:type="xsd:string"&gt;SOAP-ENV:Server 
&nbsp;          xsi:type="xsd:string"&gt;Exception caught in System::Statistics::get_virtual_compression_s 
&nbsp; tatistics() 
&nbsp; Exception: Common::NotImplemented 
&nbsp;  
&nbsp;  
&nbsp;  
&nbsp;  
&nbsp;  
&nbsp; EvaluateException: Type mismatch (http://www.w3.org/2001/XMLSchema namespace) (got string wanted QName) 
&nbsp; [Element trace: /SOAP-ENV:Envelope/SOAP-ENV:Body/SOAP-ENV:Fault/faultcode] 
&nbsp;  
&nbsp; When you see the "got string wanted QName" error, it almost always means you've generated a 500 ISE and that you've not passed in the correct structure - I know this error well! 
&nbsp;  
&nbsp; Anyhow, handling these exceptions with a try: is probably the best way, since about all you'll get is the QName error which is fairly useless but conforms to the spec according to the ZSI folks... 
&nbsp;  
&nbsp; I hope this is useful. At some point I'll try and do a write-up on debugging and give examples of some of the common data structures that get passed into various calls. 
&nbsp;  
&nbsp; -Matt

roberto_75166 · Answer

If you want to get the appropriate exceptions from the box, instead of the "generic" QNAME error, you can have that with a small change in the ZSI library. 
&nbsp;  
&nbsp; In the ZSI folder (in the site-packages directory, or inside the appropriate .egg file), just edit the fault.py file, and look for the FaultType.typecode definition. Within it, where it reads "QName(pname='faultcode')", change it to "String(pname='faultcode')". Save it and you should be able to get the expected "FaultException" instead of the dreaded EvaluateException.

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