bugfixes in dealing with services

roles/gpu/tasks/main.yml

@@ -133,17 +133,17 @@
     name: nvidia-persistenced
     state: stopped
   become: true
-  when: uninstall_driver and ( services["nvidia-persistenced.service"].state == "running")
+  when: uninstall_driver and services["nvidia-persistenced.service"] is defined
 
 - name: stop the create-dev-uvm daemon
   service: name=create-dev-uvm state=stopped
   become: true
-  when: uninstall_driver and  services["create-dev-uvm.service"].state  == "running"
+  when: uninstall_driver and services["create-dev-uvm.service"] is defined
 
 - name: stop the telegraf daemon
   service: name=telegraf state=stopped
   become: true
-  when: uninstall_driver and  services["telegraf.service"].state  == "running"
+  when: uninstall_driver and services["telegraf.service"] is defined
 
 
 - name: Unload nvidia driver
@@ -234,16 +234,16 @@
   service: name=nvidia-persistenced state=started
   become: true
   become_user: root
-  when: uninstall_driver and services["nvidia-persistenced.service"].state == "running"
+  when: uninstall_driver and services["nvidia-persistenced.service"] is defined and services["nvidia-persistenced.service"].state == "running"
 
 - name: re-start the create-dev-uvm daemon
   service: name=create-dev-uvm state=started
   become: true
   become_user: root
-  when: uninstall_driver and services["create-dev-uvm.service"].state == "running"
+  when: uninstall_driver and services["create-dev-uvm.service"] is defined and services["create-dev-uvm.service"].state == "running"
 
 - name: re-start the telegraf daemon
   service: name=telegraf state=started
   become: true
   become_user: root
-  when: uninstall_driver and services["telegraf.service"].state == "running"
+  when: uninstall_driver and services["telegraf.service"] is defined and services["telegraf.service"].state == "running"