write_conf.py

#!/usr/bin/env python3
import json
import os
import os.path
import sys
import urllib.request
from subprocess import run, PIPE
import shutil

SRC = 'https://s3-eu-west-1.amazonaws.com/maurin-d2si/formation-devops/credentials.tgz'
KEY = os.path.join(os.environ['HOME'], '.ssh', 'crashcourse')
TARGET_PATH = os.path.join(os.environ['HOME'], '.aws')
TARGET_NAME = 'credentials.test'


def is_key_pair(private, public):
    print('Checking SSH key...')
    pub_key = run(['ssh-keygen', '-y', '-f', private], stdout=PIPE)
    pub_key = pub_key.stdout.strip().decode('utf-8')
    with open(KEY + '.pub') as f:
        return f.readline().strip() == pub_key


def read_input():
    text = []
    while True:
        line = input()
        if not line:
            break
        text.append(line)
    return '\n'.join(text)


def set_ssh_key():
    if os.path.exists(KEY) and is_key_pair(KEY, KEY + '.pub'):
        print('Matching key pair 👍')
        return
    print('Please copy paste here the SSH key you were provided with.')
    ssh_key = read_input()
    with open(KEY, 'w') as f:
        print('Writing key...')
        f.write(ssh_key)
    run(['chmod', '600', KEY])
    if is_key_pair(KEY, KEY + '.pub'):
        print('Matching key pair 👍')
    else:
        print('Invalid key, please try again.')
        sys.exit(-1)


def load_all_credentials():
    if not os.path.exists('tmp'):
        os.makedirs('tmp')
    path = 'tmp/credentials.json'
    with open(path + '.tgz', 'b+w') as f:
        f.write(urllib.request.urlopen(SRC).read())
    run(['tar', '-xzf', path + '.tgz', '--directory', 'tmp'])
    # Decrypt key
    run(['openssl', 'rsautl', '-decrypt', '-ssl', '-inkey', KEY, '-in',
         'tmp/key.enc', '-out', 'tmp/key'])
    # Decrypt file with key
    run(['openssl', 'aes-256-cbc', '-d', '-in', path + '.enc', '-out', path,
         '-pass', 'file:tmp/key'])
    with open(path) as f:
        all_credentials = json.load(f)
    shutil.rmtree('tmp')
    return all_credentials


def get_credentials():
    all_credentials = load_all_credentials()
    try:
        id = int(input('What is your group number? ')) - 1
        print('============')
    except ValueError:
        print('Error: Please enter a number')
        sys.exit(-1)

    if id not in range(len(all_credentials)):
        print('Error: No credentials for this group number.')
        sys.exit(-1)
    return all_credentials[id]


def write_conf(credentials, path, name):
    if not os.path.exists(path):
        os.makedirs(path)
    with open(os.path.join(path, name), 'w') as f:
        f.write('[default]\n'
                f'aws_access_key_id={credentials["access_key"]}\n'
                f'aws_secret_access_key={credentials["secret"]}\n')
    print(f'Wrote AWS conf file in {os.path.join(path, name)}')
    print('============')


if __name__ == '__main__':
    set_ssh_key()
    print('============')
    credentials = get_credentials()
    write_conf(credentials, TARGET_PATH, TARGET_NAME)

    print('Connect to AWS using:\n'
          f'URL: {credentials["url"]}\n'
          f'Username: {credentials["username"]}\n'
          f'Password: {credentials["password"]}')