[pkg] add couch schema migration script

1 files changed, 142 insertions, 0 deletions

diff --git a/scripts/migration/0.8.2/migrate_couch_schema/__init__.py b/scripts/migration/0.8.2/migrate_couch_schema/__init__.py
new file mode 100644
index 00000000..37e5a525
--- /dev/null
+++ b/scripts/migration/0.8.2/migrate_couch_schema/__init__.py
@@ -0,0 +1,142 @@
+# __init__.py
+"""
+Support functions for migration script.
+"""
+
+import logging
+
+from couchdb import Server
+
+from leap.soledad.common.couch import GENERATION_KEY
+from leap.soledad.common.couch import TRANSACTION_ID_KEY
+from leap.soledad.common.couch import REPLICA_UID_KEY
+from leap.soledad.common.couch import DOC_ID_KEY
+from leap.soledad.common.couch import SCHEMA_VERSION_KEY
+from leap.soledad.common.couch import CONFIG_DOC_ID
+from leap.soledad.common.couch import SYNC_DOC_ID_PREFIX
+from leap.soledad.common.couch import SCHEMA_VERSION
+
+
+logger = logging.getLogger(__name__)
+
+
+#
+# support functions
+#
+
+def _get_couch_server(couch_url):
+    return Server(couch_url)
+
+
+def _is_migrateable(db):
+    config_doc = db.get('u1db_config')
+    if config_doc is None:
+        return False
+    return True
+
+
+def _get_transaction_log(db):
+    ddoc_path = ['_design', 'transactions', '_view', 'log']
+    resource = db.resource(*ddoc_path)
+    _, _, data = resource.get_json()
+    rows = data['rows']
+    transaction_log = []
+    gen = 1
+    for row in rows:
+        transaction_log.append((gen, row['id'], row['value']))
+        gen += 1
+    return transaction_log
+
+
+def _get_user_dbs(server):
+    user_dbs = filter(lambda dbname: dbname.startswith('user-'), server)
+    return user_dbs
+
+
+#
+# migration main functions
+#
+
+def migrate(args, target_version):
+    server = _get_couch_server(args.couch_url)
+    logger.info('starting couch schema migration to %s...' % target_version)
+    if not args.do_migrate:
+        logger.warning('dry-run: no changes will be made to databases')
+    user_dbs = _get_user_dbs(server)
+    for dbname in user_dbs:
+        db = server[dbname]
+        if not _is_migrateable(db):
+            logger.warning("skipping user db: %s" % dbname)
+            continue
+        logger.info("starting migration of user db: %s" % dbname)
+        _migrate_user_db(db, args.do_migrate)
+        logger.info("finished migration of user db: %s" % dbname)
+    logger.info('finished couch schema migration to %s' % target_version)
+
+
+def _migrate_user_db(db, do_migrate):
+    _migrate_transaction_log(db, do_migrate)
+    _migrate_config_doc(db, do_migrate)
+    _migrate_sync_docs(db, do_migrate)
+    _delete_design_docs(db, do_migrate)
+
+
+def _migrate_transaction_log(db, do_migrate):
+    transaction_log = _get_transaction_log(db)
+    for gen, doc_id, trans_id in transaction_log:
+        gen_doc_id = 'gen-%s' % str(gen).zfill(10)
+        doc = {
+            '_id': gen_doc_id,
+            GENERATION_KEY: gen,
+            DOC_ID_KEY: doc_id,
+            TRANSACTION_ID_KEY: trans_id,
+        }
+        logger.info('creating gen doc: %s' % (gen_doc_id))
+        if do_migrate:
+            db.save(doc)
+
+
+def _migrate_config_doc(db, do_migrate):
+    old_doc = db['u1db_config']
+    new_doc = {
+        '_id': CONFIG_DOC_ID,
+        REPLICA_UID_KEY: old_doc[REPLICA_UID_KEY],
+        SCHEMA_VERSION_KEY: SCHEMA_VERSION,
+    }
+    logger.info("moving config doc: %s -> %s"
+                % (old_doc['_id'], new_doc['_id']))
+    if do_migrate:
+        db.save(new_doc)
+        db.delete(old_doc)
+
+
+def _migrate_sync_docs(db, do_migrate):
+    view = db.view(
+        '_all_docs',
+        startkey='u1db_sync',
+        endkey='u1db_synd',
+        include_docs='true')
+    for row in view.rows:
+        old_doc = row['doc']
+        old_id = old_doc['_id']
+        replica_uid = old_id.replace('u1db_sync_', '')
+        new_id = "%s%s" % (SYNC_DOC_ID_PREFIX, replica_uid)
+        new_doc = {
+            '_id': new_id,
+            GENERATION_KEY: old_doc['generation'],
+            TRANSACTION_ID_KEY: old_doc['transaction_id'],
+            REPLICA_UID_KEY: replica_uid,
+        }
+        logger.info("moving sync doc: %s -> %s" % (old_id, new_id))
+        if do_migrate:
+            db.save(new_doc)
+            db.delete(old_doc)
+
+
+def _delete_design_docs(db, do_migrate):
+    for ddoc in ['docs', 'syncs', 'transactions']:
+        doc_id = '_design/%s' % ddoc
+        doc = db.get(doc_id)
+        logger.info("deleting design doc: %s" % doc_id)
+        if do_migrate:
+            db.delete(doc)