env-list

#!/usr/bin/env python
# -*- coding:utf-8 -*-

# 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 logging
import os
import sys

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


def set_logging_level(level):
    if level > 3:
        level = 3
    handler = request.HTTPHandler(debuglevel=level)
    request.install_opener(request.build_opener(handler))
    log_level = ['ERROR', 'WARNING', 'INFO', 'DEBUG'][level]
    logging.basicConfig(
        level=getattr(logging, log_level), format='%(levelname)-8s %(message)s',
    )


def fatal(msg):
    logging.error(msg)
    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 env_request(app, env=None):
    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)

    if env:
        env = '?' + '&'.join(['env=' + e for e in env])

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

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

    headers = {
        'Content-Type': 'application/json',
        'Accept': 'application/json'
    }
    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_vars(app, env):
    resp = env_request(app, env)
    return json.loads(resp.read().decode('utf-8'))


def parse_args():
    parser = argparse.ArgumentParser(
        description="List an App's environment variables"
    )
    parser.add_argument(
        '-a', '--app',
        required=True,
        help='the name of the App',
    )
    parser.add_argument(
        '-p', '--private',
        action='store_true',
        help='list private variables',
    )
    parser.add_argument(
        '-v', '--verbose',
        action='count',
        default=0,
        help='Logging level: v=warning, vv=info, vvv=debug',
    )
    parser.add_argument(
        'env',
        nargs='*',
        help='environment variables to list',
    )
    return parser.parse_args()


def show_var(env, private=False):
    if not env:
        return
    for var in sorted(env, key=lambda e: e['name']):
        if private or var['public']:
            print('{name}={value}'.format(**var))
        else:
            print('{name}=*** (private variable)'.format(**var))


def main():
    args = parse_args()
    set_logging_level(args.verbose)
    env = get_app_vars(args.app, args.env)
    show_var(env, args.private)


if __name__ == '__main__':
    main()