__init__.py 文件源码

def _get_connection(self):
        """Context manager providing a netmiko SSH connection object.

        This function hides the complexities of gracefully handling retrying
        failed connection attempts.
        """
        retry_exc_types = (paramiko.SSHException, EOFError)

        # Use tenacity to handle retrying.
        @tenacity.retry(
            # Log a message after each failed attempt.
            after=tenacity.after_log(LOG, logging.DEBUG),
            # Reraise exceptions if our final attempt fails.
            reraise=True,
            # Retry on SSH connection errors.
            retry=tenacity.retry_if_exception_type(retry_exc_types),
            # Stop after the configured timeout.
            stop=tenacity.stop_after_delay(
                int(self.ngs_config['ngs_ssh_connect_timeout'])),
            # Wait for the configured interval between attempts.
            wait=tenacity.wait_fixed(
                int(self.ngs_config['ngs_ssh_connect_interval'])),
        )
        def _create_connection():
            return netmiko.ConnectHandler(**self.config)

        # First, create a connection.
        try:
            net_connect = _create_connection()
        except tenacity.RetryError as e:
            LOG.error("Reached maximum SSH connection attempts, not retrying")
            raise exc.GenericSwitchNetmikoConnectError(
                config=device_utils.sanitise_config(self.config), error=e)
        except Exception as e:
            LOG.error("Unexpected exception during SSH connection")
            raise exc.GenericSwitchNetmikoConnectError(
                config=device_utils.sanitise_config(self.config), error=e)

        # Now yield the connection to the caller.
        with net_connect:
            yield net_connect