Fixes for SCVMM

- correct scvmm references
- add unit tests for scvmm detection
- ensure all matching devices are mounted and examined for scvmm configuration
- exit once vmm startup script is found and executed
- fixes Azure#185

azurelinuxagent/common/osutil/default.py

@@ -280,25 +280,27 @@ def conf_sshd(self, disable_password):
 
 
     def get_dvd_device(self, dev_dir='/dev'):
-        patten=r'(sr[0-9]|hd[c-z]|cdrom[0-9]|cd[0-9])'
-        for dvd in [re.match(patten, dev) for dev in os.listdir(dev_dir)]:
+        pattern=r'(sr[0-9]|hd[c-z]|cdrom[0-9]|cd[0-9])'
+        for dvd in [re.match(pattern, dev) for dev in os.listdir(dev_dir)]:
             if dvd is not None:
                 return "/dev/{0}".format(dvd.group(0))
         raise OSUtilError("Failed to get dvd device")
 
-    def mount_dvd(self, max_retry=6, chk_err=True):
-        dvd = self.get_dvd_device()
-        mount_point = conf.get_dvd_mount_point()
+    def mount_dvd(self, max_retry=6, chk_err=True, dvd_device=None, mount_point=None):
+        if dvd_device is None:
+            dvd_device = self.get_dvd_device()
+        if mount_point is None:
+            mount_point = conf.get_dvd_mount_point()
         mountlist = shellutil.run_get_output("mount")[1]
-        existing = self.get_mount_point(mountlist, dvd)
+        existing = self.get_mount_point(mountlist, dvd_device)
         if existing is not None: #Already mounted
-            logger.info("{0} is already mounted at {1}", dvd, existing)
+            logger.info("{0} is already mounted at {1}", dvd_device, existing)
             return
         if not os.path.isdir(mount_point):
             os.makedirs(mount_point)
 
         for retry in range(0, max_retry):
-            retcode = self.mount(dvd, mount_point, option="-o ro -t udf,iso9660",
+            retcode = self.mount(dvd_device, mount_point, option="-o ro -t udf,iso9660",
                                  chk_err=chk_err)
             if retcode == 0:
                 logger.info("Successfully mounted dvd")
@@ -310,8 +312,9 @@ def mount_dvd(self, max_retry=6, chk_err=True):
         if chk_err:
             raise OSUtilError("Failed to mount dvd.")
 
-    def umount_dvd(self, chk_err=True):
-        mount_point = conf.get_dvd_mount_point()
+    def umount_dvd(self, chk_err=True, mount_point=None):
+        if mount_point is None:
+            mount_point = conf.get_dvd_mount_point()
         retcode = self.umount(mount_point, chk_err=chk_err)
         if chk_err and retcode != 0:
             raise OSUtilError("Failed to umount dvd.")
@@ -322,7 +325,13 @@ def eject_dvd(self, chk_err=True):
         if chk_err and retcode != 0:
             raise OSUtilError("Failed to eject dvd: ret={0}".format(retcode))
 
-    def load_atappix_mod(self):
+    def try_load_atapiix_mod(self):
+        try:
+            self.load_atapiix_mod()
+        except Exception as e:
+            logger.warn("Could not load ATAPI driver: {0}".format(e.message))
+
+    def load_atapiix_mod(self):
         if self.is_atapiix_mod_loaded():
             return
         ret, kern_version = shellutil.run_get_output("uname -r")

azurelinuxagent/daemon/main.py

@@ -100,7 +100,7 @@ def daemon(self):
 
         if conf.get_detect_scvmm_env():
             self.scvmm_handler.run()
-        
+
         if conf.get_resourcedisk_format():
             self.resourcedisk_handler.run()
 

azurelinuxagent/daemon/scvmm.py

@@ -17,6 +17,7 @@
 # Requires Python 2.4+ and Openssl 1.0+
 #
 
+import re
 import os
 import sys
 import subprocess
@@ -34,21 +35,32 @@ class ScvmmHandler(object):
     def __init__(self):
         self.osutil = get_osutil()
 
-    def detect_scvmm_env(self):
+    def detect_scvmm_env(self, dev_dir='/dev'):
         logger.info("Detecting Microsoft System Center VMM Environment")
-        self.osutil.mount_dvd(max_retry=1, chk_err=False)
+        found=False
+
+        # try to load the ATAPI driver, continue on failure
+        self.osutil.try_load_atapiix_mod()
+
+        # cycle through all available /dev/sr*|hd*|cdrom*|cd* looking for the scvmm configuration file
         mount_point = conf.get_dvd_mount_point()
-        found = os.path.isfile(os.path.join(mount_point, VMM_CONF_FILE_NAME))
-        if found:
-            self.start_scvmm_agent()
-        else:
-            self.osutil.umount_dvd(chk_err=False)
+        for devices in filter(lambda x: x is not None, [re.match(r'(sr[0-9]|hd[c-z]|cdrom[0-9]?|cd[0-9]+)', dev) for dev in os.listdir(dev_dir)]):
+            dvd_device = os.path.join(dev_dir, devices.group(0))
+            self.osutil.mount_dvd(max_retry=1, chk_err=False, dvd_device=dvd_device, mount_point=mount_point)
+            found = os.path.isfile(os.path.join(mount_point, VMM_CONF_FILE_NAME))
+            if found:
+                self.start_scvmm_agent(mount_point=mount_point)
+                break
+            else:
+                self.osutil.umount_dvd(chk_err=False, mount_point=mount_point)
+
         return found
 
-    def start_scvmm_agent(self):
+    def start_scvmm_agent(self, mount_point=None):
         logger.info("Starting Microsoft System Center VMM Initialization "
                     "Process")
-        mount_point = conf.get_dvd_mount_point()
+        if mount_point is None:
+            mount_point = conf.get_dvd_mount_point()
         startup_script = os.path.join(mount_point, VMM_STARTUP_SCRIPT_NAME)
         devnull = open(os.devnull, 'w')
         subprocess.Popen(["/bin/bash", startup_script, "-p " + mount_point],

tests/distro/test_resourceDisk.py

@@ -19,11 +19,7 @@
 # http://msdn.microsoft.com/en-us/library/cc227259%28PROT.13%29.aspx
 
 from tests.tools import *
-import azurelinuxagent.distro.default.resourceDisk as resourceDisk
-from azurelinuxagent.distro.loader import get_distro
-from azurelinuxagent.distro.default.protocolUtil import *
-import azurelinuxagent.utils.fileutil as fileutil
-
+from azurelinuxagent.daemon.resourcedisk import get_resourcedisk_handler
 
 class TestResourceDisk(AgentTestCase):
     def test_mkfile(self):
@@ -34,7 +30,7 @@ def test_mkfile(self):
             os.remove(test_file)
 
         # execute
-        get_distro().resource_disk_handler.mkfile(test_file, file_size)
+        get_resourcedisk_handler().mkfile(test_file, file_size)
 
         # assert
         assert os.path.exists(test_file)

tests/distro/test_scvmm.py

@@ -0,0 +1,85 @@
+# Copyright 2014 Microsoft Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Requires Python 2.4+ and Openssl 1.0+
+#
+# Implements parts of RFC 2131, 1541, 1497 and
+# http://msdn.microsoft.com/en-us/library/cc227282%28PROT.10%29.aspx
+# http://msdn.microsoft.com/en-us/library/cc227259%28PROT.13%29.aspx
+
+import mock
+from tests.tools import *
+
+import azurelinuxagent.daemon.scvmm as scvmm
+from azurelinuxagent.daemon.main import *
+from azurelinuxagent.common.osutil.default import DefaultOSUtil
+
+class TestSCVMM(AgentTestCase):
+    def test_scvmm_detection_with_file(self):
+        # setup
+        conf.get_dvd_mount_point = Mock(return_value=self.tmp_dir)
+        conf.get_detect_scvmm_env = Mock(return_value=True)
+        scvmm_file = os.path.join(self.tmp_dir, scvmm.VMM_CONF_FILE_NAME)
+        fileutil.write_file(scvmm_file, "")
+
+        patch = mock.patch.object(scvmm.ScvmmHandler, 'start_scvmm_agent').start()
+
+        # execute
+        with self.assertRaises(SystemExit):
+            get_daemon_handler().daemon()
+
+        # assert
+        patch.assert_called()
+
+        # cleanup
+        os.remove(scvmm_file)
+
+
+    def test_scvmm_detection_with_multiple_cdroms(self):
+        # setup
+        conf.get_dvd_mount_point = Mock(return_value=self.tmp_dir)
+        conf.get_detect_scvmm_env = Mock(return_value=True)
+
+        patch_mount = mock.patch.object(DefaultOSUtil, 'mount_dvd').start()
+
+        # execute
+        with patch('os.listdir', return_value=["sr0", "sr1", "sr2"]):
+            scvmm.ScvmmHandler().detect_scvmm_env()
+
+        # assert
+        assert patch_mount.call_count == 3
+        assert patch_mount.call_args_list[0][1]['dvd_device'] == '/dev/sr0'
+        assert patch_mount.call_args_list[1][1]['dvd_device'] == '/dev/sr1'
+        assert patch_mount.call_args_list[2][1]['dvd_device'] == '/dev/sr2'
+
+
+    def test_scvmm_detection_without_file(self):
+        # setup
+        conf.get_dvd_mount_point = Mock(return_value=self.tmp_dir)
+        conf.get_detect_scvmm_env = Mock(return_value=True)
+        scvmm_file = os.path.join(self.tmp_dir, scvmm.VMM_CONF_FILE_NAME)
+        if os.path.exists(scvmm_file):
+            os.remove(scvmm_file)
+
+        patch_start = mock.patch.object(scvmm.ScvmmHandler, 'start_scvmm_agent').start()
+
+        # execute
+        scvmm.ScvmmHandler().detect_scvmm_env()
+
+        # assert
+        patch_start.assert_not_called()
+
+
+if __name__ == '__main__':
+    unittest.main()