The tenant ID should be hashed and used as the key for the JSON blob of
relevant creds for any given tenant. Azure CSP interface methods that
need to source creds should call the internal `_source_creds` method,
either with a `tenant_id` or no parameters. That method will source the
creds. If a tenant ID is provided, it will source them from the Key
Vault. If not provided, it will return the default creds for the app
registration in the home tenant.
The implementation here is meant to wrap a library of JSON policy
documents. Policies should be added to directories corresponding to
where they will be defined (portfolio, application, environment).
Functionality for parsing portfolio policy definitions is included. When
the policies need to be defined on a management group, the
AzureCloudProvider can iterate the appropriate tier of the policy
manager and add those definitions.
This adds some initial example policies:
- One for region restrictions
- One for service restrictions
Note that the MS ARM team has said that region restrictions may be
controlled by ARM, so that policy might prove unnecessary. The
parameters list for the service restrictions is stubbed for now, pending
the full list.
I also added an internal method for adding policy definitions to a
management group. This method is agnostic about what tier of management
group the policy is being defined at. It requires that a dictionary
representing the properties section of a valid Azure JSON policy
definition be passed as an argument.
