def is_postgres_error(error, *pgcodes):
# Unwrap Django's lowest-common-denominator exception.
error = get_psycopg2_exception(error)
if error is None:
# A Django error, not from the database.
return False
elif error.pgcode in pgcodes:
# A matching database-side error.
return True
else:
# Some other database-side error.
return False
def start_up(master=False):
"""Perform start-up tasks for this MAAS server.
This is used to:
- make sure the singletons required by the application are created
- sync the configuration of the external systems driven by MAAS
The method will be executed multiple times if multiple processes are used
but this method uses database locking to ensure that the methods it calls
internally are not run concurrently.
"""
while True:
try:
# Get the shared secret from Tidmouth sheds which was generated
# when Sir Topham Hatt graduated Sodor Academy. (Ensure we have a
# shared-secret so that a cluster on the same host as this region
# can authenticate.)
yield security.get_shared_secret()
# Execute other start-up tasks that must not run concurrently with
# other invocations of themselves, across the whole of this MAAS
# installation.
yield deferToDatabase(inner_start_up, master=master)
except SystemExit:
raise
except KeyboardInterrupt:
raise
except DatabaseError as e:
psycopg2_exception = get_psycopg2_exception(e)
if psycopg2_exception is None:
maaslog.warning(
"Database error during start-up; " "pausing for 3 seconds."
)
elif psycopg2_exception.pgcode is None:
maaslog.warning(
"Database error during start-up (PostgreSQL error "
"not reported); pausing for 3 seconds."
)
else:
maaslog.warning(
"Database error during start-up (PostgreSQL error %s); "
"pausing for 3 seconds.",
psycopg2_exception.pgcode,
)
logger.error("Database error during start-up", exc_info=True)
yield pause(3.0) # Wait 3 seconds before having another go.
except Exception:
maaslog.warning("Error during start-up; pausing for 3 seconds.")
logger.error("Error during start-up.", exc_info=True)
yield pause(3.0) # Wait 3 seconds before having another go.
else:
break
