Mock: Added partial support for session IDs

Note: Removal of session IDs in the mocked Logoff operation and validation
      of session IDs in any mocked operations that require to be logged on
      has not been implemented in this change. That would require passing
      the HTTP header fields to the mock support, which is not the case today
      and would require larger changes.

      However, since addition/removal/validation of session IDs is implemented
      for the FakedHmc class, this should be sufficient to provide the session
      ID support required for zhmcclient/zhmccli#413.

Details:

* Added support for dynamically creating a session ID in the
  mocked Logon operation (i.e. _urihandler.SessionsHandler).

* The new session ID is stored in the zhmcclient_mock.FakedHmc
  object in new support for adding, removing and validating
  session IDs.

* Added unit test cases for the session ID support in the
  zhmcclient_mock.FakedHmc class.

Signed-off-by: Andreas Maier <[email protected]>

design/fakedsession.md

@@ -0,0 +1,95 @@
+# Support for multiple sessions in zhmcclient mock support
+
+Issue https://github.com/zhmcclient/python-zhmcclient/issues/1437 asks for
+adding support for unique session IDs in the zhmcclient mock support.
+
+There are two aspects to this:
+1. Generating a unique session ID
+2. Supporting multiple FakedSession objects for the same FakedHmc object
+
+The first aspect can easily be implemented with the current design.
+
+The difficulty for the second aspect is that the current design makes the
+FakedHmc object a data item within the FakedSession object that is automatically
+generated, whereas a proper session support would work such that the FakedHmc
+object exists independent of the FakedSession object, and multiple FakedSession
+objects could be created against the same FakedHmc object.
+
+This document describes the relevant parts of the current design, to have a
+basis for a future support for multiple FakedSession objects for the same
+FakedHmc object.
+
+## Current design
+
+class FakedHmc(FakedBaseResource):
+
+    init parms:
+        session, hmc_name, hmc_version, api_version
+    attributes:
+        super(FakedHmc, self).__init__(
+            manager=None, properties=None)
+        self._session = session     # FakedSession object
+        self.hmc_name = hmc_name
+        self.hmc_version = hmc_version
+        self.api_version = api_version
+
+        self.cpcs = FakedCpcManager(...)
+        self.metrics_contexts = FakedMetricsContextManager(...)
+        self.consoles = FakedConsoleManager(...)
+
+        self._metric_groups
+        self._metric_values
+
+        self.all_resources
+        self._enabled
+
+class FakedSession(zhmcclient.Session):
+
+    init parms:
+        host, hmc_name, hmc_version, api_version, userid=None, password=None
+    attributes:
+        super(FakedSession, self).__init__(
+            host, userid=userid, password=password)
+        self._hmc = FakedHmc(self, hmc_name, hmc_version, api_version)
+        self._urihandler = UriHandler(URIS)
+        self._object_topic = 'faked-notification-topic'
+        self._job_topic = 'faked-job-notification-topic'
+
+Handler for "Logon" (POST /api/sessions):
+
+    def post(method, hmc, uri, uri_parms, body, logon_required,
+             wait_for_completion):
+        assert wait_for_completion is True  # synchronous operation
+        check_required_fields(method, uri, body, ['userid', 'password'])
+        result = {
+            'api-session': 'fake-session-id',
+            'notification-topic': 'fake-topic-1',
+            'job-notification-topic': 'fake-topic-2',
+            'api-major-version': 4,
+            'api-minor-version': 40,
+            'password-expires': -1,
+            # 'shared-secret-key' not included
+            'session-credential': uuid.uuid4().hex,
+        }
+        return result
+
+Handler for "Logoff" (DELETE /api/sessions/this-session):
+
+    def delete(method, hmc, uri, uri_parms, logon_required):
+        pass
+
+Typical use:
+
+      session = FakedSession('fake-host', 'fake-hmc', '2.13.1', '1.8')
+      session.hmc.consoles.add({
+          'object-id': None,
+          # object-uri will be automatically set
+          'parent': None,
+          'class': 'console',
+          'name': 'fake-console1',
+          'description': 'Console #1',
+      })
+
+      # From here on, normal zhmcclient classes/methods are used:
+      client = Client(session)
+      console = client.consoles.find(name=...)

tests/unit/zhmcclient_mock/test_hmc.py

@@ -24,6 +24,7 @@
 from datetime import datetime
 from dateutil import tz
 import pytz
+import pytest
 
 from zhmcclient_mock._session import FakedSession
 from zhmcclient_mock._hmc import \
@@ -241,6 +242,31 @@ def test_hmc_add_resources(self):
         assert port1.properties == port1_out_props
         assert port1.manager == adapter1.ports
 
+    def test_hmc_session_id(self):
+        """Test FakedHmc.validate/add/remove_session_id()."""
+
+        hmc = self.hmc
+
+        session_id = 'valid_id'
+
+        hmc.add_session_id(session_id)
+
+        result = hmc.validate_session_id(session_id)
+        assert result is True
+
+        # Adding an already valid ID fails
+        with pytest.raises(ValueError):
+            hmc.add_session_id(session_id)
+
+        hmc.remove_session_id(session_id)
+
+        result = hmc.validate_session_id(session_id)
+        assert result is False
+
+        # Removing an invalid ID fails
+        with pytest.raises(ValueError):
+            hmc.remove_session_id(session_id)
+
 
 class TestFakedBase(object):
     """All tests for the FakedBaseManager and FakedBaseResource classes."""

zhmcclient_mock/_hmc.py

@@ -889,6 +889,7 @@ def __init__(self, session, hmc_name, hmc_version, api_version):
         self.hmc_name = hmc_name
         self.hmc_version = hmc_version
         self.api_version = api_version
+        self._valid_session_ids = set()
 
         self._metric_groups = {}  # by metric group name
         for mg_dict in METRIC_GROUPS:
@@ -926,6 +927,7 @@ def __repr__(self):
             "  metrics_contexts = {metrics_contexts}\n"
             "  consoles = {consoles}\n"
             "  all_resources (keys only) = {all_resource_keys}\n"
+            "  valid_session_ids = {valid_session_ids}\n"
             ")".format(
                 classname=self.__class__.__name__,
                 id=id(self),
@@ -941,6 +943,7 @@ def __repr__(self):
                 consoles=repr_manager(self.consoles, indent=2),
                 all_resource_keys=repr_list(self.all_resources.keys(),
                                             indent=2),
+                valid_session_ids=self._valid_session_ids,
             ))
         return ret
 
@@ -999,6 +1002,59 @@ def disable(self):
         """
         self._enabled = False
 
+    def validate_session_id(self, session_id):
+        """
+        Return boolean indicating whether a session ID is valid.
+
+        Parameters:
+
+          session_id (string):
+            The session ID to be validated.
+
+        Returns:
+          bool: Whether the session ID is valid.
+        """
+        return session_id in self._valid_session_ids
+
+    def add_session_id(self, session_id):
+        """
+        Add a session ID to the valid session IDs.
+
+        If the session ID already exists, ValueError is raised.
+
+        Parameters:
+
+          session_id (string):
+            The session ID to be added.
+
+        Raises:
+            ValueError: Session ID already exists.
+        """
+        if session_id in self._valid_session_ids:
+            raise ValueError(
+                "Session ID {} already exists".format(session_id))
+
+        self._valid_session_ids.add(session_id)
+
+    def remove_session_id(self, session_id):
+        """
+        Remove a session ID from the valid session IDs.
+
+        If the session ID does not exist, ValueError is raised.
+
+        Parameters:
+
+          session_id (string):
+            The session ID to be removed.
+
+        Raises:
+            ValueError: Session ID does not exist.
+        """
+        try:
+            self._valid_session_ids.remove(session_id)
+        except KeyError:
+            raise ValueError("Session ID {} does not exist".format(session_id))
+
     def lookup_by_uri(self, uri):
         """
         Look up a faked resource by its object URI, within this faked HMC.

zhmcclient_mock/_urihandler.py

@@ -620,15 +620,18 @@ def post(method, hmc, uri, uri_parms, body, logon_required,
         """Operation: Logon."""
         assert wait_for_completion is True  # synchronous operation
         check_required_fields(method, uri, body, ['userid', 'password'])
+        session_id = uuid.uuid4().hex
+        session_cred = session_id + '-cred'
+        hmc.add_session_id(session_id)
         result = {
-            'api-session': 'fake-session-id',
+            'api-session': session_id,
             'notification-topic': 'fake-topic-1',
             'job-notification-topic': 'fake-topic-2',
             'api-major-version': 4,
             'api-minor-version': 40,
             'password-expires': -1,
             # 'shared-secret-key' not included
-            'session-credential': uuid.uuid4().hex,
+            'session-credential': session_cred,
         }
         return result
 
@@ -642,6 +645,9 @@ class ThisSessionHandler(object):
     def delete(method, hmc, uri, uri_parms, logon_required):
         # pylint: disable=unused-argument
         """Operation: Logoff."""
+        # TODO: Add support for removing the current session ID. This requires
+        #       passing the request headers, which requires changing the
+        #       FakedSession class to get control at the HTTP level.
         pass