Querying Objects¶

The InfiniBox API layer allows its users to query and sort objects according to various criteria. InfiniSDK offers a clean Pythonic syntax to perform such queries.

Querying All Objects¶

Querying all objects can be done by iterating over the collection proxies (e.g. system.volumes):

>>> system.volumes.count()
5
>>> for volume in system.volumes:
...     print("Found volume:", volume.get_name())
Found volume: vol0
Found volume: vol1
Found volume: vol2
Found volume: vol3
Found volume: vol4

Note

This is also equivalent to iterating over system.volumes.find()

Querying by Fields¶

Querying by fields is relatively easy if you want a specific field value:

>>> [v] = system.volumes.find(name='vol0')
>>> v 
<...:Volume id=...>

Getting a Single Object¶

Getting a single object has an even easier shortcut – get, which assumes only one object is returned:

>>> v = system.volumes.get(name='vol0')
>>> v 
<...:Volume id=...>

It will fail if either 0 or several objects are returned:

>>> system.volumes.get() 
Traceback (most recent call last):
  ...
TooManyObjectsFound

>>> system.volumes.get(name='nonexistent') 
Traceback (most recent call last):
  ...
ObjectNotFound

There is also safe_get, returning None instead of raising an exception if no object is found:

>>> system.volumes.safe_get(name='nonexistent') is None
True

Advanced Queries¶

Object fields can be used to perform more complex queries, using operators. For instance, here is a query for all volumes whose name is not ‘vol1’.

>>> for v in system.volumes.find(system.volumes.fields.name != 'vol1'):
...     print(v.get_name())
vol0
vol2
vol3
vol4

The above code leverages Python’s operator overloading to generate on-the-fly query filters. There is also a shorter syntax for writing the above piece of code, using the Q shortcut available from InfiniSDK:

>>> from infinisdk import Q

>>> vols = system.volumes.find(Q.name != 'vol1')
>>> len(vols)
4

Note

Q.x != y is merely a shortcut for SomeObject.fields.x != y, and provides no other additional functionality besides shortening the syntax.

Note

You can use the following operators ==, !=, >, >=, <, <=, and also .in_(...), .not_in(...), .between(x, y) and .like("string"). Not all operators are supported by all queries – some limitations might apply.

And here is a query to find all volumes greater than 1 GiB in size:

>>> from capacity import GiB
>>> system.volumes.find(system.volumes.fields.size > GiB).to_list()
[]