Use a fake serial module that will allow tests to contine

Instead of aborting all serial using tests instead just
create a serial module in cloudinit that will create a fake
and broken serial class when pyserial is not actually installed.

This allows for using the datasource and tests that exist in
a more functional and tested manner (even when pyserial is not
found).

6 files changed, 71 insertions, 45 deletions

diff --git a/cloudinit/cs_utils.py b/cloudinit/cs_utils.py
index 83ac1a0e..412431f2 100644
--- a/cloudinit/cs_utils.py
+++ b/cloudinit/cs_utils.py
@@ -33,7 +33,8 @@ API Docs: http://cloudsigma-docs.readthedocs.org/en/latest/server_context.html
 import json
 import platform
 
-import serial
+from cloudinit import serial
+
 
 # these high timeouts are necessary as read may read a lot of data.
 READ_TIMEOUT = 60
diff --git a/cloudinit/serial.py b/cloudinit/serial.py
new file mode 100644
index 00000000..af45c13e
--- /dev/null
+++ b/cloudinit/serial.py
@@ -0,0 +1,50 @@
+# vi: ts=4 expandtab
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License version 3, as
+#    published by the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+from __future__ import absolute_import
+
+try:
+    from serial import Serial
+except ImportError:
+    # For older versions of python (ie 2.6) pyserial may not exist and/or
+    # work and/or be installed, so make a dummy/fake serial that blows up
+    # when used...
+    class Serial(object):
+        def __init__(self, *args, **kwargs):
+            pass
+
+        @staticmethod
+        def isOpen():
+            return False
+
+        @staticmethod
+        def write(data):
+            raise IOError("Unable to perform serial `write` operation,"
+                          " pyserial not installed.")
+
+        @staticmethod
+        def readline():
+            raise IOError("Unable to perform serial `readline` operation,"
+                          " pyserial not installed.")
+
+        @staticmethod
+        def flush():
+            raise IOError("Unable to perform serial `flush` operation,"
+                          " pyserial not installed.")
+
+        @staticmethod
+        def read(size=1):
+            raise IOError("Unable to perform serial `read` operation,"
+                          " pyserial not installed.")
diff --git a/cloudinit/sources/DataSourceSmartOS.py b/cloudinit/sources/DataSourceSmartOS.py
index 6cbd8dfa..c7641eb3 100644
--- a/cloudinit/sources/DataSourceSmartOS.py
+++ b/cloudinit/sources/DataSourceSmartOS.py
@@ -40,13 +40,11 @@ import re
 import socket
 import stat
 
-import serial
-
 from cloudinit import log as logging
+from cloudinit import serial
 from cloudinit import sources
 from cloudinit import util
 
-
 LOG = logging.getLogger(__name__)
 
 SMARTOS_ATTRIB_MAP = {
diff --git a/tests/unittests/test_cs_util.py b/tests/unittests/test_cs_util.py
index 8c9ac0cd..56c9ce9e 100644
--- a/tests/unittests/test_cs_util.py
+++ b/tests/unittests/test_cs_util.py
@@ -2,13 +2,7 @@ from __future__ import print_function
 
 from . import helpers as test_helpers
 
-import unittest2
-
-try:
-    from cloudinit.cs_utils import Cepko
-    WILL_WORK = True
-except ImportError:
-    WILL_WORK = False
+from cloudinit.cs_utils import Cepko
 
 
 SERVER_CONTEXT = {
@@ -26,13 +20,12 @@ SERVER_CONTEXT = {
 }
 
 
-if WILL_WORK:
-    class CepkoMock(Cepko):
-        def all(self):
-            return SERVER_CONTEXT
+class CepkoMock(Cepko):
+    def all(self):
+        return SERVER_CONTEXT
 
-        def get(self, key="", request_pattern=None):
-            return SERVER_CONTEXT['tags']
+    def get(self, key="", request_pattern=None):
+        return SERVER_CONTEXT['tags']
 
 
 # 2015-01-22 BAW: This test is completely useless because it only ever tests
@@ -40,7 +33,7 @@ if WILL_WORK:
 # touched the underlying Cepko class methods.
 class CepkoResultTests(test_helpers.TestCase):
     def setUp(self):
-        raise unittest2.SkipTest('This test is completely useless')
+        raise test_helpers.SkipTest('This test is completely useless')
 
     def test_getitem(self):
         result = self.c.all()
diff --git a/tests/unittests/test_datasource/test_cloudsigma.py b/tests/unittests/test_datasource/test_cloudsigma.py
index 11968796..7950fc52 100644
--- a/tests/unittests/test_datasource/test_cloudsigma.py
+++ b/tests/unittests/test_datasource/test_cloudsigma.py
@@ -2,14 +2,8 @@
 
 import copy
 
-try:
-    # Serial does not work on py2.6 (anymore)
-    import pyserial
-    from cloudinit.cs_utils import Cepko
-    from cloudinit.sources import DataSourceCloudSigma
-    WILL_WORK = True
-except ImportError:
-    WILL_WORK = False
+from cloudinit.cs_utils import Cepko
+from cloudinit.sources import DataSourceCloudSigma
 
 from .. import helpers as test_helpers
 from ..helpers import SkipTest
@@ -36,20 +30,17 @@ SERVER_CONTEXT = {
 }
 
 
-if WILL_WORK:
-    class CepkoMock(Cepko):
-        def __init__(self, mocked_context):
-            self.result = mocked_context
+class CepkoMock(Cepko):
+    def __init__(self, mocked_context):
+        self.result = mocked_context
 
-        def all(self):
-            return self
+    def all(self):
+        return self
 
 
 class DataSourceCloudSigmaTest(test_helpers.TestCase):
     def setUp(self):
         super(DataSourceCloudSigmaTest, self).setUp()
-        if not WILL_WORK:
-            raise SkipTest("Datasource testing not supported")
         self.datasource = DataSourceCloudSigma.DataSourceCloudSigma("", "", "")
         self.datasource.is_running_in_cloudsigma = lambda: True
         self.datasource.cepko = CepkoMock(SERVER_CONTEXT)
diff --git a/tests/unittests/test_datasource/test_smartos.py b/tests/unittests/test_datasource/test_smartos.py
index 6b628276..f536ef4f 100644
--- a/tests/unittests/test_datasource/test_smartos.py
+++ b/tests/unittests/test_datasource/test_smartos.py
@@ -33,13 +33,8 @@ import tempfile
 import uuid
 from binascii import crc32
 
-try:
-    # Serial does not work on py2.6 (anymore)
-    import serial
-    from cloudinit.sources import DataSourceSmartOS
-    WILL_WORK = True
-except ImportError:
-    WILL_WORK = False
+from cloudinit import serial
+from cloudinit.sources import DataSourceSmartOS
 
 import six
 
@@ -81,8 +76,7 @@ def get_mock_client(mockdata):
 class TestSmartOSDataSource(helpers.FilesystemMockingTestCase):
     def setUp(self):
         super(TestSmartOSDataSource, self).setUp()
-        if not WILL_WORK:
-            raise SkipTest("This test will not work")
+
         self.tmp = tempfile.mkdtemp()
         self.addCleanup(shutil.rmtree, self.tmp)
         self.legacy_user_d = tempfile.mkdtemp()
@@ -448,8 +442,7 @@ class TestJoyentMetadataClient(helpers.FilesystemMockingTestCase):
 
     def setUp(self):
         super(TestJoyentMetadataClient, self).setUp()
-        if not WILL_WORK:
-            raise SkipTest("This test will not work")
+
         self.serial = mock.MagicMock(spec=serial.Serial)
         self.request_id = 0xabcdef12
         self.metadata_value = 'value'