run a custodian policy across accounts

def run(config, use, output_dir, accounts, tags, region,
        policy, policy_tags, cache_period, cache_path, metrics,
        dryrun, debug, verbose, metrics_uri):
    """run a custodian policy across accounts"""
    accounts_config, custodian_config, executor = init(
        config, use, debug, verbose, accounts, tags, policy, policy_tags=policy_tags)
    policy_counts = Counter()
    success = True

    if metrics_uri:
        metrics = metrics_uri

    if not cache_path:
        cache_path = os.path.expanduser("~/.cache/c7n-org")
        if not os.path.exists(cache_path):
            os.makedirs(cache_path)

    with executor(max_workers=WORKER_COUNT) as w:
        futures = {}
        for a in accounts_config['accounts']:
            for r in resolve_regions(region or a.get('regions', ())):
                futures[w.submit(
                    run_account,
                    a, r,
                    custodian_config,
                    output_dir,
                    cache_period,
                    cache_path,
                    metrics,
                    dryrun,
                    debug)] = (a, r)

        for f in as_completed(futures):
            a, r = futures[f]
            if f.exception():
                if debug:
                    raise
                log.warning(
                    "Error running policy in %s @ %s exception: %s",
                    a['name'], r, f.exception())

            account_region_pcounts, account_region_success = f.result()
            for p in account_region_pcounts:
                policy_counts[p] += account_region_pcounts[p]

            if not account_region_success:
                success = False

    log.info("Policy resource counts %s" % policy_counts)

    if not success:
        sys.exit(1)