Workaround for juju bug http://pad.lv/1215579

update-address

#!/usr/bin/python
"""

Juju fails to update addresses in relations when those addresses
change.  This script can be used to propagate address changes on a
unit to all of its relations and related units.

This is a workaround for http://pad.lv/1215579

You need to transfer this file to all the units with changed addresses
and make it executable. Then you need to execute this from a client machine
via juju run.

ie. say i have units x/0 and y/1 that have changed addresses::

  juju scp update-address x/0:/tmp/update-address
  juju scp update-address y/1:/tmp/update-address

  juju run --unit=x/0 --unit=y/0 "chmod +x /tmp/update-address"
  juju run --unit=x/0 --unit=y/0 "/tmp/update-address"


"""

import json
import logging
import itertools
import os
import subprocess
# not in stdlib but in cloud-image
import yaml


def main():
    md_path = os.path.join(os.environ['CHARM_DIR'], 'metadata.yaml')
    with open(md_path) as fh:
        md = yaml.safe_load(fh.read())
    addr = subprocess.check_output(['unit-get', 'private-address']).strip()

    rel_names = []
    for rel_type in ('provides', 'requires', 'peers'):
        rel_names.extend(md.get(kind, ()))

    for name in rel_names:
        rels = json.loads(
            subprocess.check_output(['relation-ids', '--format=json', name]))
        for r in rels:
            subprocess.check_output(['relation-set', '-r', r, 'private-address=%s' % addr])
        print "updated", os.environ['JUJU_UNIT_NAME'], name

if __name__ == '__main__':
    main()

Hey man,

Thank you so much for this! I forked this gist to fix some problems... If you can and want, pull it ;)

fixed, cheers.