def get_next_available_server(client_class, username, failed_host=None, component=None, create_client_fn=create_client):
'''
Given a failed host, attempts to find the next available host and returns a Sentry server if found, as well as a list
of all Sentry hosts attempted.
'''
current_host = failed_host
has_next = True
attempted_hosts = []
while has_next:
LOG.warn('Could not connect to Sentry server %s, attempting to fetch next available client.' % current_host)
next_server = get_sentry_server(current_host=current_host)
time.sleep(1)
try:
client = create_client_fn(client_class, username, next_server, component)
client.list_sentry_roles_by_group(groupName='*')
# If above operation succeeds, return client
LOG.info('Successfully connected to Sentry server %s, after attempting [%s], returning client.' % (client.host, ', '.join(attempted_hosts)))
return next_server, attempted_hosts
except StructuredThriftTransportException, e:
# If we have come back around to the original failed client, exit
if client.host == failed_host:
has_next = False
else:
current_host = client.host
attempted_hosts.append(current_host)
except Exception, e:
raise PopupException(_('Encountered unexpected error while trying to find available Sentry client: %s' % e))
def test_get_random_sentry_server(self):
# Test that with no current_host, a server for a random host is returned
xml = self._sentry_site_xml(rpc_addresses='%s,host-1,host-2' % self.rpc_addresses, rpc_port=self.rpc_port)
file(os.path.join(self.tmpdir, 'sentry-site.xml'), 'w').write(xml)
sentry_site.reset()
server = get_sentry_server()
assert_true(server is not None)
assert_true(server['hostname'] in '%s,host-1,host-2' % self.rpc_addresses)
def test_get_single_sentry_server(self):
# Test that with a current host and single server, the single server is returned
xml = self._sentry_site_xml(rpc_addresses='host-1', rpc_port=self.rpc_port)
file(os.path.join(self.tmpdir, 'sentry-site.xml'), 'w').write(xml)
sentry_site.reset()
server = get_sentry_server(current_host='host-1')
assert_true(server is not None)
assert_equal(server['hostname'], 'host-1')
def test_get_first_sentry_server(self):
# Test that if the current host is the last host of multiple servers, the first server is returned
xml = self._sentry_site_xml(rpc_addresses='host-1,%s,host-2' % self.rpc_addresses, rpc_port=self.rpc_port)
file(os.path.join(self.tmpdir, 'sentry-site.xml'), 'w').write(xml)
sentry_site.reset()
server = get_sentry_server(current_host='host-2')
assert_true(server is not None)
assert_equal(server['hostname'], 'host-1')
def get_cached_server(current_host=None):
global API_CACHE
if current_host and API_CACHE is not None:
clear_api_cache()
if API_CACHE is None:
server = get_sentry_server(current_host)
if server is not None:
set_api_cache(server)
else:
raise PopupException(_('Failed to find an available Sentry server.'))
else:
LOG.debug("Returning cached Sentry server: %s:%s" % (API_CACHE['hostname'], API_CACHE['port']))
return API_CACHE