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Diffstat (limited to 'scripts/migration/0.8-to-0.9/migrate_couch_schema/__init__.py')
| -rw-r--r-- | scripts/migration/0.8-to-0.9/migrate_couch_schema/__init__.py | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/scripts/migration/0.8-to-0.9/migrate_couch_schema/__init__.py b/scripts/migration/0.8-to-0.9/migrate_couch_schema/__init__.py new file mode 100644 index 00000000..1e51eccd --- /dev/null +++ b/scripts/migration/0.8-to-0.9/migrate_couch_schema/__init__.py @@ -0,0 +1,221 @@ +# __init__.py +""" +Support functions for migration script. +""" + +import logging + +from couchdb import Server +from couchdb import ResourceNotFound +from couchdb import ResourceConflict + +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 _has_u1db_config_doc(db): + config_doc = db.get('u1db_config') + return bool(config_doc) + + +def _get_transaction_log(db): + ddoc_path = ['_design', 'transactions', '_view', 'log'] + resource = db.resource(*ddoc_path) + try: + _, _, data = resource.get_json() + except ResourceNotFound: + logger.warning( + '[%s] missing transactions design document, ' + 'can\'t get transaction log.' % db.name) + return [] + 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 _report_missing_u1db_config_doc(dbname, db): + config_doc = db.get(CONFIG_DOC_ID) + if not config_doc: + logger.warning( + "[%s] no '%s' or '%s' documents found, possibly an empty db? I " + "don't know what to do with this db, so I am skipping it." + % (dbname, 'u1db_config', CONFIG_DOC_ID)) + else: + if SCHEMA_VERSION_KEY in config_doc: + version = config_doc[SCHEMA_VERSION_KEY] + if version == SCHEMA_VERSION: + logger.info( + "[%s] '%s' document exists, and schema versions match " + "(expected %r and found %r). This database reports to be " + "using the new schema version, so I am skipping it." + % (dbname, CONFIG_DOC_ID, SCHEMA_VERSION, version)) + else: + logger.error( + "[%s] '%s' document exists, but schema versions don't " + "match (expected %r, found %r instead). I don't know " + "how to migrate such a db, so I am skipping it." + % (dbname, CONFIG_DOC_ID, SCHEMA_VERSION, version)) + else: + logger.error( + "[%s] '%s' document exists, but has no schema version " + "information in it. I don't know how to migrate such a db, " + "so I am skipping it." % (dbname, CONFIG_DOC_ID)) + + +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 _has_u1db_config_doc(db): + _report_missing_u1db_config_doc(dbname, db) + continue + logger.info("[%s] starting migration of user db" % dbname) + try: + _migrate_user_db(db, args.do_migrate) + logger.info("[%s] finished migration of user db" % dbname) + except: + logger.exception('[%s] error migrating user db' % dbname) + logger.error('continuing with next database.') + logger.info('finished couch schema migration to %s' % target_version) + + +def _migrate_user_db(db, do_migrate): + _migrate_transaction_log(db, do_migrate) + _migrate_sync_docs(db, do_migrate) + _delete_design_docs(db, do_migrate) + _migrate_config_doc(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.debug('[%s] creating gen doc: %s' % (db.name, gen_doc_id)) + if do_migrate: + try: + db.save(doc) + except ResourceConflict: + # this gen document already exists. if documents are the same, + # continue with migration. + existing_doc = db.get(gen_doc_id) + for key in [GENERATION_KEY, DOC_ID_KEY, TRANSACTION_ID_KEY]: + if existing_doc[key] != doc[key]: + raise + + +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("[%s] moving config doc: %s -> %s" + % (db.name, old_doc['_id'], new_doc['_id'])) + if do_migrate: + # the config doc must not exist, otherwise we would have skipped this + # database. + db.save(new_doc) + db.delete(old_doc) + + +def _migrate_sync_docs(db, do_migrate): + logger.info('[%s] moving sync docs' % db.name) + 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'] + + # older schemas used different documents with ids starting with + # "u1db_sync" to store sync-related data: + # + # - u1db_sync_log: was used to store the whole sync log. + # - u1db_sync_state: was used to store the sync state. + # + # if any of these documents exist in the current db, they are leftover + # from previous migrations, and should just be removed. + if old_id in ['u1db_sync_log', 'u1db_sync_state']: + logger.info('[%s] removing leftover document: %s' + % (db.name, old_id)) + if do_migrate: + db.delete(old_doc) + continue + + 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.debug("[%s] moving sync doc: %s -> %s" + % (db.name, old_id, new_id)) + if do_migrate: + try: + db.save(new_doc) + except ResourceConflict: + # this sync document already exists. if documents are the same, + # continue with migration. + existing_doc = db.get(new_id) + for key in [GENERATION_KEY, TRANSACTION_ID_KEY, + REPLICA_UID_KEY]: + if existing_doc[key] != new_doc[key]: + raise + 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) + if doc: + logger.info("[%s] deleting design doc: %s" % (db.name, doc_id)) + if do_migrate: + db.delete(doc) + else: + logger.warning("[%s] design doc not found: %s" % (db.name, doc_id)) |