host: split cached_vm identification from import_vm

This will be useful to the plugin that allows not rerunning a cached
dependency: it needs to probe the cache.

Signed-off-by: Yann Dirson <[email protected]>

Author: ydirson

lib/host.py

@@ -200,22 +200,31 @@ def xo_server_reconnect(self):
         # is not enough to guarantee that the host object exists yet.
         wait_for(lambda: xo_object_exists(self.uuid), "Wait for XO to know about HOST %s" % self.uuid)
 
+    @staticmethod
+    def vm_cache_key(uri):
+        return f"[Cache for {strip_suffix(uri, '.xva')}]"
+
+    def cached_vm(self, uri, sr_uuid):
+        assert sr_uuid, "A SR UUID is necessary to use import cache"
+        cache_key = self.vm_cache_key(uri)
+        # Look for an existing cache VM
+        vm_uuids = safe_split(self.xe('vm-list', {'name-description': cache_key}, minimal=True), ',')
+
+        for vm_uuid in vm_uuids:
+            vm = VM(vm_uuid, self)
+            # Make sure the VM is on the wanted SR.
+            # Assumption: if the first disk is on the SR, the VM is.
+            # If there's no VDI at all, then it is virtually on any SR.
+            if not vm.vdi_uuids() or vm.get_sr().uuid == sr_uuid:
+                logging.info(f"Reusing cached VM {vm.uuid} for {uri}")
+                return vm
+        logging.info("Not found vm in cache with key %r", cache_key)
+
     def import_vm(self, uri, sr_uuid=None, use_cache=False):
         if use_cache:
-            assert sr_uuid, "A SR UUID is necessary to use import cache"
-            cache_key = f"[Cache for {strip_suffix(uri, '.xva')}]"
-            # Look for an existing cache VM
-            vm_uuids = safe_split(self.xe('vm-list', {'name-description': cache_key}, minimal=True), ',')
-
-            for vm_uuid in vm_uuids:
-                vm = VM(vm_uuid, self)
-                # Make sure the VM is on the wanted SR.
-                # Assumption: if the first disk is on the SR, the VM is.
-                # If there's no VDI at all, then it is virtually on any SR.
-                if not vm.vdi_uuids() or vm.get_sr().uuid == sr_uuid:
-                    logging.info(f"Reusing cached VM {vm.uuid} for {uri}")
-                    return vm
-            logging.info("Not found vm in cache with key %r", cache_key)
+            vm = self.cached_vm(uri, sr_uuid)
+            if vm:
+                return vm
 
         params = {}
         msg = "Import VM %s" % uri
@@ -235,6 +244,7 @@ def import_vm(self, uri, sr_uuid=None, use_cache=False):
         for vif in vm.vifs():
             vif.move(self.management_network())
         if use_cache:
+            cache_key = self.vm_cache_key(uri)
             logging.info(f"Marking VM {vm.uuid} as cached")
             vm.param_set('name-description', cache_key)
         return vm