#!/usr/bin/env python

# Update the base image that is used for devstack VMs.

# Copyright (C) 2011-2012 OpenStack LLC.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
#
# See the License for the specific language governing permissions and
# limitations under the License.

import time
import socket

import paramiko

from sshclient import SSHClient


def iterate_timeout(max_seconds, purpose):
    start = time.time()
    count = 0
    while (time.time() < start + max_seconds):
        count += 1
        yield count
        time.sleep(2)
    raise Exception("Timeout waiting for %s" % purpose)


def ssh_connect(ip, username, connect_kwargs={}, timeout=60):
    # HPcloud may return errno 111 for about 30 seconds after adding the IP
    for count in iterate_timeout(timeout, "ssh access"):
        try:
            client = SSHClient(ip, username, **connect_kwargs)
            break
        except socket.error as e:
            print "While testing ssh access:", e
            time.sleep(5)
        except paramiko.ssh_exception.AuthenticationException:
            return None

    ret, out = client.ssh("echo access okay")
    if "access okay" in out:
        return client
    return None