def __get_rest_hosts(self):
"""
Return the list of hosts as they should be tried. First comes the main
host. Then the fallback hosts in random order.
The returned list will have a length of up to http_max_retry_count.
"""
# Defaults
host = self.rest_host
if host is None:
host = Defaults.rest_host
environment = self.environment
if environment is None:
environment = Defaults.environment
http_max_retry_count = self.http_max_retry_count
if http_max_retry_count is None:
http_max_retry_count = Defaults.http_max_retry_count
# Prepend environment
if environment != 'production':
host = '%s-%s' % (environment, host)
# Fallback hosts
fallback_hosts = self.fallback_hosts
if fallback_hosts is None:
if host == Defaults.rest_host or self.fallback_hosts_use_default:
fallback_hosts = Defaults.fallback_hosts
elif environment != 'production':
fallback_hosts = Defaults.get_environment_fallback_hosts(environment)
else:
fallback_hosts = []
# Explicit warning about deprecating the option
if self.fallback_hosts_use_default:
if environment != Defaults.environment:
warnings.warn(
"It is no longer required to set 'fallback_hosts_use_default', the correct fallback hosts "
"are now inferred from the environment, 'fallback_hosts': {}"
.format(','.join(fallback_hosts)), DeprecationWarning
)
else:
warnings.warn(
"It is no longer required to set 'fallback_hosts_use_default': 'fallback_hosts': {}"
.format(','.join(fallback_hosts)), DeprecationWarning
)
# Shuffle
fallback_hosts = list(fallback_hosts)
random.shuffle(fallback_hosts)
# First main host
hosts = [host] + fallback_hosts
hosts = hosts[:http_max_retry_count]
return hosts
def test_fallback_hosts(self):
# Specify the fallback_hosts (RSC15a)
fallback_hosts = [
['fallback1.com', 'fallback2.com'],
[],
]
# Fallback hosts specified (RSC15g1)
for aux in fallback_hosts:
ably = AblyRest(token='foo', fallback_hosts=aux)
assert sorted(aux) == sorted(
ably.options.get_fallback_rest_hosts())
# Specify environment (RSC15g2)
ably = AblyRest(token='foo',
environment='sandbox',
http_max_retry_count=10)
assert sorted(
Defaults.get_environment_fallback_hosts('sandbox')) == sorted(
ably.options.get_fallback_rest_hosts())
# Fallback hosts and environment not specified (RSC15g3)
ably = AblyRest(token='foo', http_max_retry_count=10)
assert sorted(Defaults.fallback_hosts) == sorted(
ably.options.get_fallback_rest_hosts())
# Specify environment and fallback_hosts_use_default, no fallback hosts (RSC15g4)
# We specify http_max_retry_count=10 so all the fallback hosts get in the list
ably = AblyRest(token='foo',
environment='not_considered',
fallback_hosts_use_default=True,
http_max_retry_count=10)
assert sorted(Defaults.fallback_hosts) == sorted(
ably.options.get_fallback_rest_hosts())
# RSC15f
ably = AblyRest(token='foo')
assert 600000 == ably.options.fallback_retry_timeout
ably = AblyRest(token='foo', fallback_retry_timeout=1000)
assert 1000 == ably.options.fallback_retry_timeout
with warnings.catch_warnings(record=True) as ws:
# Cause all warnings to always be triggered
warnings.simplefilter("always")
AblyRest(token='foo', fallback_hosts_use_default=True)
# Verify warning is raised for fallback_hosts_use_default
ws = [w for w in ws if issubclass(w.category, DeprecationWarning)]
assert len(ws) == 1
