Comment 10 for bug 1506112

Here is root cause analysis from duplicate bug:

The error can occur if master node aperates slowly.

In this case it can execute code from

nailgun/nailgun/utils/logs.py

    # rename bootstrap directory into fqdn
    if os.path.islink(old):
        logger.debug("Old %s exists and it is link. "
                     "Trying to unlink", old)
        os.unlink(old)
    if os.path.isdir(old):
        logger.debug("Old %s exists and it is directory. "
                     "Trying to rename into %s", old, new)
        os.rename(old, new)
    else:
        logger.debug("Creating %s", new)
        os.makedirs(new)

    # creating symlinks
    for l in links:
        if os.path.islink(l) or os.path.isfile(l):
            logger.debug("%s already exists. "
                         "Trying to unlink", l)
            os.unlink(l)
        if os.path.isdir(l):
            logger.debug("%s already exists and it directory. "
                         "Trying to remove", l)
            shutil.rmtree(l)
---------------------
Then syslog server continues receiving messaqges from node, it recreates missing <ip>/bootstrap directory and writes some files there. Then nailgun process continues
------------------------
        logger.debug("Creating symlink %s -> %s", l, new)
        os.symlink(objects.Node.get_node_fqdn(node), l) <<<<<<<<<<<<<<< error!