I'm having having difficulty getting the tenacity library to work as expected. The retry in the following test doesn't trigger at all. I would expect a retry every 5 seconds and for the log file to reflect the retry attempts.

import paramiko
import tenacity
from configparser import RawConfigParser
import loggingdef main():parser = RawConfigParser()parser.read('config.ini')HOST = parser['SSH']['host']PORT = parser['SSH']['port']USER = parser['SSH']['user']LOG_LEVEL = parser['Logging']['level']LOG_FILE = parser['Files']['log_file']LOG_FORMAT = parser['Logging']['format']with open(LOG_FILE, "a") as f:logging.basicConfig(filename=LOG_FILE,level=LOG_LEVEL,format=LOG_FORMAT)logging.info("******Started logging******")client = paramiko.SSHClient()client.set_missing_host_key_policy(paramiko.AutoAddPolicy())@tenacity.retry(wait=tenacity.wait_fixed(5))def connect():try:client.connect(HOST, int(PORT), USER)logging.info("Successful connection to remote server")except Exception:logging.error("Cannot connect to remote server")connect()if __name__ == "__main__":main()

The log file spits this out:

> 2017-11-04 19:55:20,695 ******Started logging******
> 2017-11-04 19:55:20,695 Cannot connect to remote server

I suppose that tenacity detects failures by handling exceptions. In your code the exception is logged and then discarded. So, for tenacity, your call is actually successful. You should re-raise this exception to get the expected behavior. Like this:

@tenacity.retry(wait=tenacity.wait_fixed(5))
def connect():try:client.connect(HOST, int(PORT), USER)logging.info("Successful connection to remote server")except Exception:logging.error("Cannot connect to remote server")raise