def test_with(self):
class SpecialException(RuntimeError):
pass
m = DynamoDbMutex(random_name(), holder=random_name())
try:
with m:
assert m.is_locked()
time.sleep(3)
raise SpecialException
except SpecialException:
print("In exception handler")
assert not m.is_locked()
def configure_vpx(vpx_info, services):
try:
NS_URL = vpx_info['ns_url']
NS_LOGIN = os.environ['NS_LOGIN']
NS_PASSWORD = os.environ.get('NS_PASSWORD')
if NS_PASSWORD is None or NS_PASSWORD == 'SAME_AS_INSTANCE_ID':
NS_PASSWORD = vpx_info['instance_id']
instance_id = vpx_info['instance_id']
state_bucket = os.environ['S3_TFSTATE_BUCKET']
config_bucket = os.environ['S3_TFCONFIG_BUCKET']
except KeyError as ke:
logger.warn("Bailing since we can't get the required variable: " +
ke.args[0])
return
vip_config = ''
vip = vpx_info.get('vip')
if vip is not None:
vip_config = "-var '" + 'vip_config={{vip="{}"}}'.format(vip) + "'"
logger.info(vpx_info)
configure_snip(vpx_info)
fetch_tfstate(state_bucket, instance_id)
fetch_tfconfig(config_bucket)
command = "{} NS_URL={} NS_LOGIN={} NS_PASSWORD={} {}/terraform apply -state={} -backup=- -no-color -var-file={}/terraform.tfvars -var 'backend_services=[{}]' {} {}".format(tf_log, NS_URL, NS_LOGIN, NS_PASSWORD, bindir, get_tfstate_path(instance_id), tfconfig_local_dir, services, vip_config, tfconfig_local_dir)
logger.info("****Executing on NetScaler: " + instance_id +
" command: " + command)
try:
m = DynamoDbMutex(name=instance_id, holder=random_name(),
timeoutms=40 * 1000)
if m.lock():
tf_output = subprocess.check_output(command, stderr=subprocess.STDOUT, shell=True)
logger.info("****Executed terraform apply on NetScaler:" +
instance_id + ", output follows***")
logger.info(tf_output)
upload_tfstate(state_bucket, instance_id)
m.release()
else:
logger.warn("Failed to acquire mutex (no-op)")
except subprocess.CalledProcessError as cpe:
logger.warn("****ERROR executing terraform apply cmd on NetScaler: " +
instance_id + ", error follows***")
logger.warn(cpe.output)
m.release()
except:
logger.warn("Caught exception: " + str(sys.exc_info()[:2]))
logger.warn("Caught exception, releasing lock")
m.release()
def test_create_delete_us_east_1(self):
m = DynamoDbMutex(random_name(),
holder=random_name(),
region_name='us-east-1')
assert (m.lock())
m.release()
DynamoDbMutex.delete_table(region_name='us-east-1')
def test_with_fail(self):
name = random_name()
m1 = DynamoDbMutex(name, holder=random_name())
m1.lock()
m2 = DynamoDbMutex(name, holder=random_name())
exceptionHappened = False
try:
with m2:
time.sleep(3)
except AcquireLockFailedError:
print("In exception handler")
assert (m2.is_locked() == False)
exceptionHappened = True
assert (exceptionHappened)
def main(args):
setup_logging()
import inspect, argparse
spec = inspect.getargspec(DynamoDbMutex.__init__)
defaults = dict(zip(reversed(spec.args), reversed(spec.defaults)))
parser = argparse.ArgumentParser(
description='Mutexes for AWS using conditional PUTs in DynamoDB.')
# required positionals
parser.add_argument('mutex',
metavar='MUTEX',
help='The name of the mutex.')
parser.add_argument('action',
metavar='ACTION',
choices=['lock', 'release'],
help='The action to take on the mutex.')
# optional flags
assert defaults['region_name'] is None
parser.add_argument(
'--region',
'-r',
metavar='NAME',
help=
'The name of the AWS region to host the mutexes in. The default depends on your Boto3 '
'configuration: http://boto3.readthedocs.io/en/latest/guide/configuration.html'
)
parser.add_argument(
'--holder',
'-H',
metavar='NAME',
help=
'A name identifying the lock holder. The default is dynamically generated UUID.'
)
parser.add_argument(
'--expiration',
'-e',
metavar='SECONDS',
type=float,
default=defaults['expiration'],
help=
'The number of seconds after which a lock is released automatically.')
parser.add_argument(
'--blocking',
'-b',
action='store_' + ('false' if defaults['blocking'] else 'true'),
help='Do not exit until the mutex is locked or a timeout occurs.')
parser.add_argument(
'--timeout',
'-t',
metavar='SECONDS',
type=float,
default=defaults['timeout'],
help=
'The maximum amount of time to block on attempting to lock a mutex.')
options = parser.parse_args(args=args)
mutex = DynamoDbMutex(options.mutex,
region_name=options.region,
holder=options.holder,
expiration=options.expiration,
timeout=options.timeout,
blocking=options.blocking)
if options.action == 'lock':
return mutex.lock()
elif options.action == 'release':
mutex.release()
return True
else:
assert False
def test_release_expired(self):
name = random_name()
caller = "caller1"
m1 = DynamoDbMutex(name, holder=caller, expiration=2)
m1.lock()
time.sleep(3)
caller = "caller2"
m2 = DynamoDbMutex(name, holder=caller, expiration=2)
assert (m2.lock())
m1.release()
assert (m2.is_locked())
m2.release()
def test_mutual_exclusion(self):
m = DynamoDbMutex(random_name(), holder=random_name())
m.lock()
assert (m.lock() == False)
m.release()
def test_timeout(self):
m = DynamoDbMutex(random_name(), holder="myself", expiration=3)
m.lock()
time.sleep(5)
assert (m.lock())
m.release()
def test_create(self):
m = DynamoDbMutex(random_name(), holder="myself", expiration=3)
assert (m.lock())
m.release()