Improved handling of unknown OS, Distribution

Introduce UnknownSystemExcpetion to indicate that the system is
is unknonwn. Catch said exception in cloud-setup-management,
print an error and exit.

CLOUDSTACK-966: Improve error reporting when running on unknown OS / version

Signed-off-by: Prasanna Santhanam <tsp@apache.org>

client/bindir/cloud-setup-management.in

@@ -16,8 +16,9 @@
 # specific language governing permissions and limitations
 # under the License.
 
+import sys
 from cloudutils.syscfg import sysConfigFactory
-from cloudutils.utilities import initLoging
+from cloudutils.utilities import initLoging, UnknownSystemException
 from cloudutils.cloudException import CloudRuntimeException, CloudInternalException
 from cloudutils.globalEnv import globalEnv
 from cloudutils.serviceConfigServer import cloudManagementConfig
@@ -35,7 +36,12 @@ if __name__ == '__main__':
     glbEnv.mode = "Server"
     
     print "Starting to configure CloudStack Management Server:"
+    try:
         syscfg = sysConfigFactory.getSysConfigFactory(glbEnv)
+    except UnknownSystemException:
+        print >>sys.stderr, ("Error: CloudStack failed to detect your "
+                "operating system. Exiting.")
+        sys.exit(1)
     try:
     	syscfg.registerService(cloudManagementConfig)
         syscfg.config()

python/lib/cloudutils/utilities.py

@@ -97,6 +97,10 @@ def writeProgressBar(msg, result):
     sys.stdout.write(output)
     sys.stdout.flush()
 
+class UnknownSystemException(Exception):
+    "This Excption is raised if the current operating enviornment is unknown"
+    pass
+ 
 class Distribution:
     def __init__(self):
         self.distro = "Unknown"
@@ -120,7 +124,7 @@ class Distribution:
             self.arch = bash("uname -m").getStdout()
             
         else: 
-            self.distro = "Unknown" 
+            raise UnknownSystemException
 
     def getVersion(self):
         return self.distro