Input validation needed for naming properties

[mtimm]

In the simple aci toolkit is possible to add a naming property that is greater than 64 characters long or contains invalid characters per the naming property input validator and the toolkit does not catch it until the property is sent to the APIC and an error is returned. This is problematic in several ways:

• No generic exception is raised from the aci toolkit if the backend flags that an error occurred. It is being left up to the application to detect the error. It is more desirable to have the simple aci toolkit check for the requests response being not ok and raise an exception specific to the simple aci toolkit and expose the error from the backend in some way and allow the application to handle it.
• Right now all of the examples in the sample directory do not handle these errors. It would be nice to show how they should be handled by applications that use the toolkit.
• The CLI mode provided by the simple aci toolkit fails to configure things without informing the user of the failure. Then if the user tries to switchto the mode that they think they configured - because they were not told that it failed - the CLI mode script will fail ungracefully.

There may be other reasons but this seems sufficient for one issue report.

[mtimm]

Here's an example of using the cli script where something obviously wrong happened and yet the script failed in a totally unexpected way. I alluded to it in the comments when I opened the issue. The behavior is now different on the exact same setup so it appears that the fabric I was using may have had an issue at the time that this occurred but the error that is returned is not what one would expect I think:

fabric(config)# tenant mtimm-acitoolkit
Executing create tenant command
fabric(config)# exit
fabric# switchto mtimm-acitoolkit
Traceback (most recent call last):
  File "acitoolkitcli.py", line 1126, in <module>
    cmdLine.cmdloop()
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/cmd.py", line 142, in cmdloop
    stop = self.onecmd(line)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/cmd.py", line 221, in onecmd
    return func(arg)
  File "acitoolkitcli.py", line 1019, in do_switchto
    if Tenant.exists(self.apic, tenant):
  File "/local/insieme/Simple-ACI-Toolkit/acitoolkit.py", line 37, in exists
    apic_tenants = cls.get(session)
  File "/local/insieme/Simple-ACI-Toolkit/acitoolkit.py", line 28, in get
    return BaseACIObject.get(session, cls, 'fvTenant')
  File "/local/insieme/Simple-ACI-Toolkit/acibaseobject.py", line 302, in get
    name = str(object_data[apic_class]['attributes']['name'])
KeyError: 'fvTenant'