Changeset 1611

Timestamp:

Nov 10, 2008, 11:41:13 PM (15 years ago)

Author:

broder

Message:

Eliminate the need for a deep copy of database objects during the
migration with weird SQLAlchemy haxory.

This requires the migration script to have its own unique version of
the database library

Location:

trunk/scripts

Files:

• lib (added)
• lib/database.py (added)
• xvm-migrate-machine (modified) (2 diffs)

trunk/scripts/xvm-migrate-machine

@@ -8 +8 @@
 
 
-from invirt import database
+from lib import database
 
 dev_db_uri = 'postgres://sipb-xen@sipb-xen-dev.mit.edu/sipb_xen'
+database.connect(dev_db_uri)
+dev_sess = database.session
 
+database.connect()
+prod_sess = database.session
 
 def take_data(machine_name):
 ## dump from dev db; save info well
-  database.connect(dev_db_uri)
-  database.session.begin()
-  machine = database.Machine.query().get_by(name=machine_name)
-  disks = database.Disk.query().filter_by(machine=machine).all()
-  nics = database.NIC.query().filter_by(machine=machine).all()
-## remove from dev db; ideally atomic with dump
+  dev_sess.begin()
+  machine = dev_sess.query(database.Machine).filter_by(name=machine_name).one()
+  
+  # Clean out the ACL just so we don't have to think about it
+  machine.acl = []
+  dev_sess.update(machine)
+  
+  disks = machine.disks
+  nics = machine.nics
   for r in disks + nics + [machine]:
     database.session.delete(r)
+  
   database.session.commit()
-  return machine, disks, nics
-
+  
+  for r in disks + nics + [machine]:
+    dev_sess.expunge(i)
+    del i._instance_key
+  
+  return machine
 
 ## shut down if up
@@ -38 +50 @@
 
 ## add to dev db
-def restore_data(machine, disks, nics):
-  database.connect() # to prod DB
-  database.session.begin()
+def restore_data(machine):
+  machine.type = prod_sess.query(database.Type).filter_by(type_id=machine.type.type_id).one()
+  prod_sess.begin()
   ## now copy machine, disks, nics to new ORM objects (yuck, oh well)
   ## and database.session.save(those)
-  database.session.commit()
+  prod_sess.save(machine)
+  prod_sess.commit()