packer.py 文件源码

def download_box(pname):
    "just download the vagrant .box for given project"
    boxurl = box_url(pname)
    if not boxurl.startswith('s3://'):
        print 'this task only downloads from s3. unhandled url', boxurl
        exit(1)
    dest = join('/tmp', os.path.basename(boxurl))
    if os.path.exists(dest):
        print 'file %s already exists, skipping download. move or rename the file to re-download' % dest
        return dest
    cmd = "aws s3 cp %s %s" % (boxurl, dest)
    assert local(cmd).return_code == 0, "failed to successfully download %s" % boxurl
    return dest