Remove ucloud_common and put its files under ucloud.common subpackage.

Remove individual config.py used by every component and put them into single config.py ucloud/config.py
Use /etc/ucloud/ucloud.conf for Environment Variables
Refactoring and a lot of it
Make ucloud repo a package and different components of ucloud a subpackage for avoiding code duplication.
Improved logging.

scheduler/helper.py

@@ -1,21 +1,15 @@
-import bitmath
-
 from collections import Counter
 from functools import reduce
 
-from ucloud_common.vm import VmPool, VMStatus
-from ucloud_common.host import HostPool, HostStatus
-from ucloud_common.request import RequestEntry, RequestPool, RequestType
+import bitmath
 
-from decouple import config
-from config import etcd_client as client
-
-vm_pool = VmPool(client, config("VM_PREFIX"))
-host_pool = HostPool(client, config("HOST_PREFIX"))
-request_pool = RequestPool(client, config("REQUEST_PREFIX"))
+from common.host import HostStatus
+from common.request import RequestEntry, RequestType
+from common.vm import VMStatus
+from config import vm_pool, host_pool, request_pool, env_vars
 
 
-def accumulated_specs(vms_specs):    
+def accumulated_specs(vms_specs):
     if not vms_specs:
         return {}
     return reduce((lambda x, y: Counter(x) + Counter(y)), vms_specs)
@@ -23,7 +17,7 @@ def accumulated_specs(vms_specs):
 
 def remaining_resources(host_specs, vms_specs):
     # Return remaining resources host_specs - vms
-    
+
     _vms_specs = Counter(vms_specs)
     _remaining = Counter(host_specs)
 
@@ -69,7 +63,7 @@ def get_suitable_host(vm_specs, hosts=None):
         # Find out remaining resources after
         # host_specs - already running vm_specs
         remaining = remaining_resources(host.specs, running_vms_accumulated_specs)
-       
+
         # Find out remaining - new_vm_specs
         remaining = remaining_resources(remaining, vm_specs)
 
@@ -111,7 +105,8 @@ def assign_host(vm):
 
     r = RequestEntry.from_scratch(type=RequestType.StartVM,
                                   uuid=vm.uuid,
-                                  hostname=vm.hostname)
+                                  hostname=vm.hostname,
+                                  request_prefix=env_vars.get("REQUEST_PREFIX"))
     request_pool.put(r)
 
     vm.log.append("VM scheduled for starting")