added service executable check, added error message to gui for service load errors

daemon/core/services/__init__.py

@@ -15,6 +15,7 @@ def load():
     """
     Loads all services from the modules that reside under core.services.
 
-    :return: nothing
+    :return: list of services that failed to load
+    :rtype: list[str]
     """
-    ServiceManager.add_services(_PATH)
+    return ServiceManager.add_services(_PATH)

daemon/core/services/bird.py

@@ -10,6 +10,7 @@ class Bird(CoreService):
     Bird router support
     """
     name = "bird"
+    executables = ("bird",)
     group = "BIRD"
     depends = ()
     dirs = ("/etc/bird",)
@@ -91,6 +92,7 @@ class BirdService(CoreService):
     """
 
     name = None
+    executables = ("bird",)
     group = "BIRD"
     depends = ("bird",)
     dirs = ()

daemon/core/services/dockersvc.py

@@ -113,6 +113,7 @@ class DockerService(CoreService):
         node.
     """
     name = "Docker"
+    executables = ("docker",)
     group = "Docker"
     depends = ()
     dirs = ('/var/lib/docker/containers/', '/run/shm', '/run/resolvconf',)

daemon/core/services/sdn.py

@@ -11,14 +11,8 @@ class SdnService(CoreService):
     """
     Parent class for SDN services.
     """
-    name = None
     group = "SDN"
-    depends = ()
-    dirs = ()
-    configs = ()
     startindex = 50
-    startup = ()
-    shutdown = ()
 
     @classmethod
     def generateconfig(cls, node, filename, services):
@@ -27,6 +21,7 @@ class SdnService(CoreService):
 
 class OvsService(SdnService):
     name = "OvsService"
+    executables = ("ovs-ofctl", "ovs-vsctl")
     group = "SDN"
     depends = ()
     dirs = ("/etc/openvswitch", "/var/run/openvswitch", "/var/log/openvswitch")
@@ -101,6 +96,7 @@ class OvsService(SdnService):
 
 class RyuService(SdnService):
     name = "ryuService"
+    executables = ("ryu-manager",)
     group = "SDN"
     depends = ()
     dirs = ()

daemon/core/services/xorp.py

@@ -12,6 +12,7 @@ class XorpRtrmgr(CoreService):
     enabled XORP services, and launches necessary daemons upon startup.
     """
     name = "xorp_rtrmgr"
+    executables = ("xorp_rtrmgr",)
     group = "XORP"
     depends = ()
     dirs = ("/etc/xorp",)
@@ -75,6 +76,7 @@ class XorpService(CoreService):
     common to XORP's routing daemons.
     """
     name = None
+    executables = ("xorp_rtrmgr",)
     group = "XORP"
     depends = ("xorp_rtrmgr",)
     dirs = ()