Adds a PPA by using urllib to get it's key. Useful when you are behind a restrictive proxy (I think I created it because apt-add-repository was having some problems with a proxy configuration...)

ppa-adder.py

#!/usr/bin/env python
from __future__ import unicode_literals
from __future__ import print_function
import contextlib
import subprocess
import tempfile
import urllib2
import os.path
import bs4


class InvalidPPA(Exception):
    pass


def get_key(skterm):
    keyserver = 'http://keyserver.ubuntu.com:11371'
    keysearch_url = keyserver + '/pks/lookup?search=0x{0}&op=vindex'.format(skterm)

    with contextlib.closing(urllib2.urlopen(keysearch_url)) as page:
        soup = bs4.BeautifulSoup(page.read())
        key_url = soup.select('body pre a')[0].attrs.get('href')

    if not key_url.startswith('http'):
        key_url = keyserver + key_url

    with contextlib.closing(urllib2.urlopen(key_url)) as page:
        soup = bs4.BeautifulSoup(page.read())
        key = soup.select('body pre')[0].text.strip()

    return key


def get(name):
    if not name.startswith('ppa:'):
        raise InvalidPPA(name)

    components = name[4:].split('/')
    if len(components) != 2:
        raise InvalidPPA(name)

    url = 'https://launchpad.net/~{0}/+archive/{1}'.format(*components)

    with contextlib.closing(urllib2.urlopen(url)) as page:
        soup = bs4.BeautifulSoup(page.read())
        sk = soup.select('#signing-key code')[0].text.strip()
        src = soup.select('#sources-list-entries')[0].text.strip()

    skterm = sk.split('/')[-1]

    return dict(name=name, key=get_key(skterm), src=src)


def add(ppa):
    release_file = '/etc/lsb-release'

    upstream_release_file = '/etc/upstream-release/lsb-release'
    if os.path.isfile(upstream_release_file):
        release_file = upstream_release_file

    with open(release_file) as lsb:
        relinfo = dict(line.strip().split('=') for line in lsb.readlines())

    version = relinfo['DISTRIB_CODENAME']

    srcfname = '-'.join(tuple(ppa['name'][4:].split('/')) + (version,)) + '.list'

    fd, path = tempfile.mkstemp(text=True)
    with contextlib.closing(os.fdopen(fd, 'w')) as keyfile:
        keyfile.write(ppa['key'])
        keyfile.flush()

        if subprocess.call(['apt-key', 'add', path]):
            raise RuntimeError('failed to add the key')

    with open(os.path.join('/etc/apt/sources.list.d', srcfname), 'w') as srcfile:
        srcfile.write(ppa['src'].replace('YOUR_UBUNTU_VERSION_HERE', version))


def main(argv):
    add(get(argv[1]))


if __name__ == '__main__':
    import sys
    sys.exit(main(sys.argv) or 0)