Return a dict of JID metadata, or None

def read_proc_file(path, opts):
    '''
    Return a dict of JID metadata, or None
    '''
    serial = salt.payload.Serial(opts)
    with salt.utils.files.fopen(path, 'rb') as fp_:
        try:
            data = serial.load(fp_)
        except Exception as err:
            # need to add serial exception here
            # Could not read proc file
            log.warning("Issue deserializing data: %s", err)
            return None

    if not isinstance(data, dict):
        # Invalid serial object
        log.warning("Data is not a dict: %s", data)
        return None

    pid = data.get('pid', None)
    if not pid:
        # No pid, not a salt proc file
        log.warning("No PID found in data")
        return None

    return data