app-address

#!/usr/bin/env python

# Copyright 2016 Pablo Santiago Blum de Aguiar <scorphus@gmail.com>. All rights
# reserved. Use of this source code is governed by the BSD 2-Clause License that
# can be found in the LICENSE file.

import argparse
import json
import os
import sys

try:
    from urllib import request
except ImportError:
    import urllib2 as request


def fatal(msg):
    sys.stderr.write(msg + '\n')
    sys.exit(5)


def get_env(name):
    env = os.environ.get(name)
    if not env:
        fatal('ERROR: missing {}'.format(name))
    return env


class Request(request.Request):

    def __init__(self, method, *args, **kwargs):
        self._method = method
        request.Request.__init__(self, *args, **kwargs)

    def get_method(self):
        return self._method


def app_request(app):
    target = get_env('TSURU_TARGET').rstrip('/')
    token = get_env('TSURU_TOKEN')

    if not target.startswith('http://') and not target.startswith('https://'):
        target = 'http://{}'.format(target)

    url = '{}/apps/{}'.format(target, app)

    req = Request('GET', url)
    req.add_header('Authorization', 'bearer ' + token)

    headers = {
        'Content-Type': 'application/json',
        'Accept': 'text/plain'
    }
    if headers:
        for header, value in headers.items():
            req.add_header(header, value)

    try:
        return request.urlopen(req, timeout=30)
    except Exception as e:
        fatal('{}'.format(e))


def get_app(app):
    resp = app_request(app)
    return json.loads(resp.read().decode('utf-8'))


def parse_args():
    parser = argparse.ArgumentParser(description="Show an App's address(es)")
    parser.add_argument(
        '-a', '--app',
        required=True,
        help='The name of the App',
    )
    parser.add_argument(
        '-o', '--one',
        action='store_true',
        help='Show only one URL',
    )
    parser.add_argument(
        '-i', '--ip',
        action='store_true',
        help='Show the "IP" URL',
    )
    return parser.parse_args()


def show_address(address, one):
    if type(address) is not list:
        address = [address]
    if one:
        print(address[-1])
    else:
        print('\n'.join(address))


def main():
    args = parse_args()
    app = get_app(args.app)
    address = app.get('cname', [])
    if not address or args.ip:
        address = app.get('ip')
    else:
        address.insert(0, app.get('ip'))
    show_address(address, args.one)


if __name__ == '__main__':
    main()