def dict_diff(first, second):
    """ Return a dict of keys that differ with another config object.  If a value is
        not found in one fo the configs, it will be represented by KEYNOTFOUND.
        @param first:   Fist dictionary to diff.
        @param second:  Second dicationary to diff.
        @return diff:   Dict of Key => (first.val, second.val)
    """
    KEYNOTFOUND = '<KEYNOTFOUND>'
    diff = {}
    # Check all keys in first dict
    for key in first:
        if (key not in second):
            diff[key] = (first[key], KEYNOTFOUND)
        elif (first[key] != second[key]):
            diff[key] = (first[key], second[key])
    # Check all keys in second dict to find missing
    for key in second:
        if (key not in first):
            diff[key] = (KEYNOTFOUND, second[key])
    return diff