New module: xenserver_guest_facts - returns facts of XenServer VMs (#49426)

* Initial commit for xenserver_guest_facts module
* New module: xenserver_guest_facts. Returns facts of XenServer VMs. Module is fully documented.
* Added unit tests for the module
* Moved FakeXenAPI import to a dedicated fixture, other fixes
* Removed unused imports, minor fixes to unit test code

test/units/modules/cloud/xenserver/FakeXenAPI.py

@@ -0,0 +1,66 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright: (c) 2019, Bojan Vitnik <bvitnik@mainstream.rs>
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+FAKE_API_VERSION = "1.1"
+
+
+class Failure(Exception):
+    def __init__(self, details):
+        self.details = details
+
+    def __str__(self):
+        return str(self.details)
+
+
+class Session(object):
+    def __init__(self, uri, transport=None, encoding=None, verbose=0,
+                 allow_none=1, ignore_ssl=False):
+
+        self.transport = transport
+        self._session = None
+        self.last_login_method = None
+        self.last_login_params = None
+        self.API_version = FAKE_API_VERSION
+
+    def _get_api_version(self):
+        return FAKE_API_VERSION
+
+    def _login(self, method, params):
+        self._session = "OpaqueRef:fake-xenapi-session-ref"
+        self.last_login_method = method
+        self.last_login_params = params
+        self.API_version = self._get_api_version()
+
+    def _logout(self):
+        self._session = None
+        self.last_login_method = None
+        self.last_login_params = None
+        self.API_version = FAKE_API_VERSION
+
+    def xenapi_request(self, methodname, params):
+        if methodname.startswith('login'):
+            self._login(methodname, params)
+            return None
+        elif methodname == 'logout' or methodname == 'session.logout':
+            self._logout()
+            return None
+        else:
+            # Should be patched with mocker.patch().
+            return None
+
+    def __getattr__(self, name):
+        if name == 'handle':
+            return self._session
+        elif name == 'xenapi':
+            # Should be patched with mocker.patch().
+            return None
+        elif name.startswith('login') or name.startswith('slave_local'):
+            return lambda *params: self._login(name, params)
+        elif name == 'logout':
+            return self._logout
+
+
+def xapi_local():
+    return Session("http://_var_lib_xcp_xapi/")

test/units/modules/cloud/xenserver/common.py

@@ -0,0 +1,11 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright: (c) 2019, Bojan Vitnik <bvitnik@mainstream.rs>
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+
+def fake_xenapi_ref(xenapi_class):
+    return "OpaqueRef:fake-xenapi-%s-ref" % xenapi_class

test/units/modules/cloud/xenserver/conftest.py

@@ -0,0 +1,44 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright: (c) 2019, Bojan Vitnik <bvitnik@mainstream.rs>
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+
+import sys
+import importlib
+import pytest
+
+
+@pytest.fixture(autouse=True)
+def XenAPI():
+    """Imports and returns fake XenAPI module."""
+
+    # Import of fake XenAPI module is wrapped by fixture so that it does not
+    # affect other unit tests which could potentialy also use XenAPI module.
+
+    # First we use importlib.import_module() to import the module and assign
+    # it to a local symbol.
+    fake_xenapi = importlib.import_module('units.module_utils.xenserver.FakeXenAPI')
+
+    # Now we populate Python module cache with imported fake module using the
+    # original module name (XenAPI). That way, any 'import XenAPI' statement
+    # will just load already imported fake module from the cache.
+    sys.modules['XenAPI'] = fake_xenapi
+
+    return fake_xenapi
+
+
+@pytest.fixture
+def xenserver_guest_facts(XenAPI):
+    """Imports and returns xenserver_guest_facts module."""
+
+    # Since we are wrapping fake XenAPI module inside a fixture, all modules
+    # that depend on it have to be imported inside a test function. To make
+    # this easier to handle and remove some code repetition, we wrap the import
+    # of xenserver_guest_facts module with a fixture.
+    from ansible.modules.cloud.xenserver import xenserver_guest_facts
+
+    return xenserver_guest_facts

test/units/modules/cloud/xenserver/test_xenserver_guest_facts.py

@@ -0,0 +1,77 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright: (c) 2019, Bojan Vitnik <bvitnik@mainstream.rs>
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+
+import json
+import pytest
+
+from .common import fake_xenapi_ref
+
+pytestmark = pytest.mark.usefixtures('patch_ansible_module')
+
+
+testcase_module_params = {
+    "params": [
+        {
+            "hostname": "somehost",
+            "username": "someuser",
+            "password": "somepwd",
+            "name": "somevmname",
+        },
+        {
+            "hostname": "somehost",
+            "username": "someuser",
+            "password": "somepwd",
+            "uuid": "somevmuuid",
+        },
+        {
+            "hostname": "somehost",
+            "username": "someuser",
+            "password": "somepwd",
+            "name": "somevmname",
+            "uuid": "somevmuuid",
+        },
+    ],
+    "ids": [
+        "name",
+        "uuid",
+        "name+uuid",
+    ],
+}
+
+
+@pytest.mark.parametrize('patch_ansible_module', testcase_module_params['params'], ids=testcase_module_params['ids'], indirect=True)
+def test_xenserver_guest_facts(mocker, capfd, XenAPI, xenserver_guest_facts):
+    """
+    Tests regular module invocation including parsing and propagation of
+    module params and module output.
+    """
+    fake_vm_facts = {"fake-vm-fact": True}
+
+    mocker.patch('ansible.modules.cloud.xenserver.xenserver_guest_facts.get_object_ref', return_value=None)
+    mocker.patch('ansible.modules.cloud.xenserver.xenserver_guest_facts.gather_vm_params', return_value=None)
+    mocker.patch('ansible.modules.cloud.xenserver.xenserver_guest_facts.gather_vm_facts', return_value=fake_vm_facts)
+
+    mocked_xenapi = mocker.patch.object(XenAPI.Session, 'xenapi', create=True)
+
+    mocked_returns = {
+        "pool.get_all.return_value": [fake_xenapi_ref('pool')],
+        "pool.get_default_SR.return_value": fake_xenapi_ref('SR'),
+    }
+
+    mocked_xenapi.configure_mock(**mocked_returns)
+
+    mocker.patch('ansible.module_utils.xenserver.get_xenserver_version', return_value=[7, 2, 0])
+
+    with pytest.raises(SystemExit):
+        xenserver_guest_facts.main()
+
+    out, err = capfd.readouterr()
+    result = json.loads(out)
+
+    assert result['instance'] == fake_vm_facts