Charm fetcher

fetch.py

#!/usr/bin/env python

import os
import yaml
import shutil
import urllib
import zipfile

from theblues.charmstore import CharmStore


cs = CharmStore('https://api.jujucharms.com/v4')


class Charm(object):
    def __init__(self, url):
        if not url.startswith('cs:'):
            raise Exception('Not a charm I care about')
        if '~' in url:
            raise Exception('Do not care about personal urls')
        self.id = url.replace('cs:', '')
        self.url = url
        self.series, self.name, self.version = [self.id.split('/')[0]] + self.id.split('/')[1].rsplit('-', 1)
        self.version = int(self.version)
        self.archive = cs.archive_url(self.id)

    def download(self, to):
        filename, _ = urllib.urlretrieve(self.archive)
        z = zipfile.ZipFile(filename)
        z.extractall(os.path.join(to, self.name))
        os.unlink(filename)


def load_manifest(manifest):
    contents = {}
    if os.path.isfile(manifest):
        with open(manifest, 'r') as m:
            contents = yaml.safe_load(m.read())
    return contents


def save_manifest(manifest, manifest_file):
    with open(manifest_file, 'w') as f:
        f.write(yaml.safe_dump(manifest, default_flow_style=False))


def list_charms(series='trusty'):
    return [Charm(c['Id']) for c in cs.search('', series=series, limit=300, promulgated_only=True)]
    

def refresh(series, output):
    if not os.path.exists(output):
        os.makedirs(output)

    manifest_file = os.path.join(output, 'manifest.yaml')
    manifest = load_manifest(manifest_file)

    charms = list_charms(series)
    for charm in charms:
        current_version = manifest.get(charm.name, -1)
        if charm.version <= current_version:
            print('SKIP  %s' % charm.id)
            continue
        if os.path.exists(os.path.join(output, charm.name)):
            shutil.rmtree(os.path.join(output, charm.name))
        print('FETCH %s' % charm.id)
        charm.download(output)
        manifest[charm.name] = charm.version
        save_manifest(manifest, manifest_file)


def main():
    cwd = os.getcwd()
    for dir in ['precise', 'trusty']:
        refresh(dir, os.path.join(cwd, dir))


if __name__ == '__main__':
    main()