import logging
from ming.orm import ORMSession
from .model import MigrationInfo
from .migrate import Migration
from . import graph
log = logging.getLogger(__name__)
MIGRATION_GRAPH = None
def run_migration(datastore, target_versions, dry_run):
'''Attempt to migrate the database to a specific set of required
modules & versions.'''
# Get the migration status of the db
session = MigrationInfo.__mongometa__.session
session.bind = datastore
ormsession = ORMSession(session)
info = MigrationInfo.m.get()
if info is None:
info = MigrationInfo.make({})
latest_versions = Migration.latest_versions()
for k,v in target_versions.iteritems():
cur = info.versions.get(k, -1)
islatest = ' (LATEST)' if v == latest_versions[k] else ''
log.info('Target %s=%s%s (current=%s)', k, v, islatest, cur)
# Create a migration plan
plan = list(plan_migration(session, ormsession, info, target_versions))
# Execute (or print) the plan
for step in plan:
log.info('Migrate %r', step)
if dry_run: continue
step.apply(info.versions)
info.m.save()
def show_status(datastore):
# Get the migration status of the db
session = MigrationInfo.__mongometa__.session
session.bind = datastore
info = MigrationInfo.m.get()
if info is None:
info = MigrationInfo.make({})
for k,v in info.versions.iteritems():
log.info('%s=%s', k, v)
def set_status(datastore, target_versions):
# Get the migration status of the db
session = MigrationInfo.__mongometa__.session
session.bind = datastore
info = MigrationInfo.m.get()
if info is None:
info = MigrationInfo.make({})
latest_versions = Migration.latest_versions()
for k,v in target_versions.iteritems():
cur = info.versions.get(k, -1)
islatest = ' (LATEST)' if v == latest_versions[k] else ''
log.info('FORCE %s=%s%s (current=%s)', k, v, islatest, cur)
info.versions.update(target_versions)
info.m.save()
def plan_migration(session, ormsession, info, target):
'''Return the optimal list of graph.MigrationSteps to run in order to
satisfy the target requirements'''
global MIGRATION_GRAPH
if MIGRATION_GRAPH is None:
migrations = dict((k, v(session, ormsession))
for k,v in Migration.migrations_registry.iteritems())
MIGRATION_GRAPH = graph.MigrationGraph(migrations)
else:
MIGRATION_GRAPH.reset()
return MIGRATION_GRAPH.shortest_path(info.versions, target)
def reset_migration(datastore, dry_run):
'''Reset the state of the database to non-version-controlled WITHOUT migrating
This is equivalent to setting all the versions to -1.'''
session = MigrationInfo.__mongometa__.session
session.bind = datastore
log.info('Reset migrations')
if not dry_run:
MigrationInfo.m.remove()