Cloud functions work much the same way as cloud actions, except that they don't perform an operation on a specific instance, and so do not need a machine name to be specified. However, since they perform an operation on a specific cloud provider, that provider must be specified.
$ salt-cloud -f show_image ec2 image=ami-fd20ad94
There are three universal salt-cloud functions that are extremely useful for gathering information about instances on a provider basis:
$ salt-cloud -f list_nodes linode
$ salt-cloud -f list_nodes_full linode
$ salt-cloud -f list_nodes_select linode
Another useful reference for viewing salt-cloud functions is the :ref:Salt Cloud Feature Matrix <salt-cloud-feature-matrix>
Docs for previous releases are available on readthedocs.org.
Latest Salt release: 2015.5.2