def tcp(cls, service, params):
"""
Consul TCP Check
This feature is only available when using Consul 0.6 or newer.
Containers specifying these extra metadata in labels or environment will be used to register
an TCP health check with the service.
SERVICE_443_CHECK_TCP=true
SERVICE_443_CHECK_INTERVAL=15s
SERVICE_443_CHECK_TIMEOUT=3s # optional, Consul default used otherwise
"""
# https://github.com/cablehead/python-consul/blob/53eb41c4760b983aec878ef73e72c11e0af501bb/consul/base.py#L85
# https://github.com/gliderlabs/registrator/blob/master/docs/user/backends.md#consul-tcp-check
tcp = cls._bool_value(params, 'tcp')
if tcp:
# Attempt to establish a tcp connection to the specified *host* and
# *port* at a specified *interval* with optional *timeout* and optional
# *deregister* after which a failing service will be automatically
# deregistered.
host = service.ip
port = service.port
interval, deregister = cls._common_values(params)
timeout = cls._value(params, 'timeout')
ret = Check.tcp(host,
port,
interval,
timeout=timeout,
deregister=deregister)
return cls._post_process(ret, params)
return None
