Remove ESXI from config

ESXI datacenter name is no longer configurable

Change-Id: Ib66a0f097724f9a5fca55854f08210bad6ec31f2
Partial-Bug: #1778707

config.yaml.template

@@ -5,7 +5,6 @@ esxi:
   password:
   preferred_api_versions:
     - vim.version.version10
-  datacenter:
 vcenter:
   host:
   port: 443

cvm/clients.py

@@ -80,9 +80,6 @@ def __init__(self):
         self._si = None
         self._datacenter = None
 
-    def _get_datacenter(self, name):
-        return self._get_object([vim.Datacenter], name)
-
     def _get_object(self, vimtype, name):
         """
          Get the vsphere object associated with a given text name
@@ -107,7 +104,7 @@ def __init__(self, esxi_cfg):
             port=esxi_cfg.get('port'),
             preferredApiVersions=esxi_cfg.get('preferred_api_versions')
         )
-        self._datacenter = self._get_datacenter(esxi_cfg.get('datacenter'))
+        self._datacenter = self._si.content.rootFolder.childEntity[0]
         atexit.register(Disconnect, self._si)
         self._property_collector = self._si.content.propertyCollector
         self._wait_options = vmodl.query.PropertyCollector.WaitOptions()
@@ -204,6 +201,9 @@ def _get_dvs_by_uuid(self, uuid):
         dvs_manager = self._si.content.dvSwitchManager
         return dvs_manager.QueryDvsByUuid(uuid)
 
+    def _get_datacenter(self, name):
+        return self._get_object([vim.Datacenter], name)
+
     @staticmethod
     def enable_vlan_override(portgroup):
         pg_config_spec = make_pg_config_vlan_override(portgroup)