def get_facts(device):
    """
    Gathers facts from a <file-show/> RPC on the '/etc/hosts.junos' file.
    """
    iri_hostname = None
    iri_ip = None
    rsp = device.rpc.file_show(filename='/etc/hosts.junos', normalize=False)
    if rsp is not None:
        hosts_file_content = rsp.findtext('.', default='')
        if hosts_file_content is not None:
            for line in hosts_file_content.splitlines():
                line, _, _ = line.partition('#')
                components = line.split(None)
                if len(components) > 1:
                    ip = components[0]
                    hosts = components[1:]
                    if iri_hostname is None:
                        iri_hostname = {}
                    if iri_ip is None:
                        iri_ip = {}
                    if ip in iri_hostname:
                        iri_hostname[ip] += hosts
                    else:
                        iri_hostname[ip] = hosts
                    for host in hosts:
                        if host in iri_ip:
                            iri_ip[host].append(ip)
                        else:
                            iri_ip[host] = [ip]
                    for host in hosts:
                        if '%d' in host:
                            octets = ip.split('.', 3)
                            for count in range(255):
                                t_ip = octets[0] + '.' + octets[1] + '.' + str(
                                    count) + '.' + octets[3]
                                t_host = host.replace('%d', str(count))
                                if t_ip in iri_hostname:
                                    iri_hostname[t_ip].append(t_host)
                                else:
                                    iri_hostname[t_ip] = [t_host]
                                if t_host in iri_ip:
                                    iri_ip[t_host].append(t_ip)
                                else:
                                    iri_ip[t_host] = [t_ip]
    return {'_iri_hostname': iri_hostname, '_iri_ip': iri_ip}
