Creating snapshot failed by schema validation when its description contains new line control character

This issue is originally reported at downstream in Red Hat.

Summary:
Creating snapshot failed by schema validation when its description contains new line control character.

Details:
The sample output is
~~~
$ openstack volume snapshot create --volume cirros_boot --description "test with new line
character for snapshot volume" test_snapshot
Invalid input for field/attribute description. Value: test with new line
character for snapshot volume. 'test with new line\ncharacter for snapshot volume' does not match '^[\\ -\\~\\\xa0-\\¬\\®-\\ͷ\\ͺ-\\Ϳ\\΄-\\Ί\\Ό\\Ύ-\\Ρ\\Σ-\\ԯ\\Ա-\\Ֆ\\ՙ-\\՟\\ա-\\և\\։-\\֊\\֍-\\֏\\֑-\\ׇ\\א-\\ת\\װ-\\״\\؆-\\؛\\؞-\\ۜ\\۞-\\܍\\ܐ-\\݊\\ݍ-\\ޱ\\߀-\\ߺ\\ࠀ-\\࠭\\࠰-\\࠾\\ࡀ-\\࡛\\࡞\\ࢠ-\\ࢴ\\ࢶ-\\ࢽ\\ࣔ-\\࣡\\ࣣ-\\ঃ\\অ-\\ঌ\\এ-\\ঐ\\ও-\\ন\\প-\\র\\ল\\শ-\\হ\\়-\\ৄ\\ে-\\ৈ\\ো-\\ৎ\\ৗ\\ড়-\\ঢ়\\য়-\\ৣ\\০-\\৻\\ਁ-\\ਃ\\ਅ-\\ਊ\\ਏ-\\ਐ\\ਓ-\\ਨ\\ਪ-\\ਰ\\ਲ-\\ਲ਼\\ਵ-\\ਸ਼\\ਸ-\\ਹ\\਼\\ਾ-\\ੂ\\ੇ-\\ੈ\\ੋ-\\੍\\ੑ\\ਖ਼-\\ੜ\\ਫ਼\\੦-\\ੵ\\ઁ-\\ઃ\\અ-\\ઍ\\એ-\\ઑ\\ઓ-\\ન\\પ-\\ર\\લ-\\ળ\\વ-\\હ\\઼-\\ૅ\\ે-\\ૉ\\ો-\\્\\ૐ\\ૠ-\\ૣ\\૦-\\૱\\ૹ\\ଁ-\\ଃ\\ଅ-\\ଌ\\ଏ-\\ଐ\\ଓ-\\ନ\\ପ-\\ର\\ଲ-\\ଳ\\ଵ-\\ହ\\଼-\\ୄ\\େ-\\ୈ\\ୋ-\\୍\\ୖ-\\ୗ\\ଡ଼-\\ଢ଼\\ୟ-\\ୣ\\୦-\\୷\\ஂ-\\ஃ\\அ-\\ஊ\\எ-\\ஐ\\ஒ-\\க\\ங-\\ச\\ஜ\\ஞ-\\ட\\ண-\\த\\ந-\\ப\\ம-\\ஹ\\ா-\\ூ\\ெ-\\ை\\ொ-\\்\\ௐ\\ௗ\\௦-\\௺\\ఀ-\\ః\\అ-\\ఌ\\ఎ-\\ఐ\\ఒ-\\న\\ప-\\హ\\ఽ-\\ౄ\\ె-\\ై\\ొ-\\్\\ౕ-\\ౖ\\ౘ-\\ౚ\\ౠ-\\ౣ\\౦-\\౯\\౸-\\ಃ\\ಅ-\\ಌ\\ಎ-\\ಐ\\ಒ-\\ನ\\ಪ-\\ಳ\\ವ-\\ಹ\\಼-\\ೄ\\ೆ-\\ೈ\\ೊ-\\್\\ೕ-\\ೖ\\ೞ\\ೠ-\\ೣ\\೦-\\೯\\ೱ-\\ೲ\\ഁ-\\ഃ\\അ-\\ഌ\\എ-\\ഐ\\ഒ-\\ഺ\\ഽ-\\ൄ\\െ-\\ൈ\\ൊ-\\൏\\ൔ-\\ൣ\\൦-\\ൿ\\ං-\\ඃ\\අ-\\ඖ\\ක-\\න\\ඳ-\\ර\\ල\\ව-\\ෆ\\්\\ා-\\ු\\ූ\\ෘ-\\ෟ\\෦-\\෯\\ෲ-\\෴\\ก-\\ฺ\\฿-\\๛\\ກ-\\ຂ\\ຄ\\ງ-\\ຈ\\ຊ\\ຍ\\ດ-\\ທ\\ນ-\\ຟ\\ມ-\\ຣ\\ລ\\ວ\\ສ-\\ຫ\\ອ-\\ູ\\ົ-\\ຽ\\ເ-\\ໄ\\ໆ\\່-\\ໍ\\໐-\\໙\\ໜ-\\ໟ\\ༀ-\\ཇ\\ཉ-\\ཬ\\ཱ-\\ྗ\\ྙ-\\ྼ\\྾-\\࿌\\࿎-\\࿚\\က-\\Ⴥ\\Ⴧ\\Ⴭ\\ა-\\ቈ\\ቊ-\\ቍ\\ቐ-\\ቖ\\ቘ\\ቚ-\\ቝ\\በ-\\ኈ\\ኊ-\\ኍ\\ነ-\\ኰ\\ኲ-\\ኵ\\ኸ-\\ኾ\\ዀ\\ዂ-\\ዅ\\ወ-\\ዖ\\ዘ-\\ጐ\\ጒ-\\ጕ\\ጘ-\\ፚ\\፝-\\፼\\ᎀ-\\᎙\\Ꭰ-\\Ᏽ\\ᏸ-\\ᏽ\\᐀-\\᚜\\ᚠ-\\ᛸ\\ᜀ-\\ᜌ\\ᜎ-\\᜔\\ᜠ-\\᜶\\ᝀ-\\ᝓ\\ᝠ-\\ᝬ\\ᝮ-\\ᝰ\\ᝲ-\\ᝳ\\ក-\\៝\\០-\\៩\\៰-\\៹\\᠀-\\᠍\\᠐-\\᠙\\ᠠ-\\ᡷ\\ᢀ-\\ᢪ\\ᢰ-\\ᣵ\\ᤀ-\\ᤞ\\ᤠ-\\ᤫ\\ᤰ-\\᤻\\᥀\\᥄-\\ᥭ\\ᥰ-\\ᥴ\\ᦀ-\\ᦫ\\ᦰ-\\ᧉ\\᧐-\\᧚\\᧞-\\ᨛ\\᨞-\\ᩞ\\᩠-\\᩼\\᩿-\\᪉\\᪐-\\᪙\\᪠-\\᪭\\᪰-\\᪾\\ᬀ-\\ᭋ\\᭐-\\᭼\\ᮀ-\\᯳\\᯼-\\᰷\\᰻-\\᱉\\ᱍ-\\ᲈ\\᳀-\\᳇\\᳐-\\ᳶ\\᳸-\\᳹\\ᴀ-\\᷵\\᷻-\\ἕ\\Ἐ-\\Ἕ\\ἠ-\\ὅ\\Ὀ-\\Ὅ\\ὐ-\\ὗ\\Ὑ\\Ὓ\\Ὕ\\Ὗ-\\ώ\\ᾀ-\\ᾴ\\ᾶ-\\ῄ\\ῆ-\\ΐ\\ῖ-\\Ί\\῝-\\`\\ῲ-\\ῴ\\ῶ-\\῾\\\u2000-\\\u200a\\‐-\\‧\\\u202f-\\\u205f\\⁰-\\ⁱ\\⁴-\\₎\\ₐ-\\ₜ\\₠-\\₾\\⃐-\\⃰\\℀-\\↋\\←-\\⏾\\␀-\\␦\\⑀-\\⑊\\①-\\⭳\\⭶-\\⮕\\⮘-\\⮹\\⮽-\\⯈\\⯊-\\⯑\\⯬-\\⯯\\Ⰰ-\\Ⱞ\\ⰰ-\\ⱞ\\Ⱡ-\\ⳳ\\⳹-\\ⴥ\\ⴧ\\ⴭ\\ⴰ-\\ⵧ\\ⵯ-\\⵰\\⵿-\\ⶖ\\ⶠ-\\ⶦ\\ⶨ-\\ⶮ\\ⶰ-\\ⶶ\\ⶸ-\\ⶾ\\ⷀ-\\ⷆ\\ⷈ-\\ⷎ\\ⷐ-\\ⷖ\\ⷘ-\\ⷞ\\ⷠ-\\⹄\\⺀-\\⺙\\⺛-\\⻳\\⼀-\\⿕\\⿰-\\⿻\\\u3000-\\〿\\ぁ-\\ゖ\\゙-\\ヿ\\ㄅ-\\ㄭ\\ㄱ-\\ㆎ\\㆐-\\ㆺ\\㇀-\\㇣\\ㇰ-\\㈞\\㈠-\\㋾\\㌀-\\䶵\\䷀-\\鿕\\ꀀ-\\ꒌ\\꒐-\\꓆\\ꓐ-\\ꘫ\\Ꙁ-\\꛷\\꜀-\\Ɪ\\Ʞ-\\ꞷ\\ꟷ-\\꠫\\꠰-\\꠹\\ꡀ-\\꡷\\ꢀ-\\ꣅ\\꣎-\\꣙\\꣠-\\ꣽ\\꤀-\\꥓\\꥟-\\ꥼ\\ꦀ-\\꧍\\ꧏ-\\꧙\\꧞-\\ꧾ\\ꨀ-\\ꨶ\\ꩀ-\\ꩍ\\꩐-\\꩙\\꩜-\\ꫂ\\ꫛ-\\꫶\\ꬁ-\\ꬆ\\ꬉ-\\ꬎ\\ꬑ-\\ꬖ\\ꬠ-\\ꬦ\\ꬨ-\\ꬮ\\ꬰ-\\ꭥ\\ꭰ-\\꯭\\꯰-\\꯹\\가-\\힣\\ힰ-\\ퟆ\\ퟋ-\\ퟻ\\豈-\\舘\\並-\\龎\\ff-\\st\\ﬓ-\\ﬗ\\יִ-\\זּ\\טּ-\\לּ\\מּ\\נּ-\\סּ\\ףּ-\\פּ\\צּ-\\﯁\\ﯓ-\\﴿\\ﵐ-\\ﶏ\\ﶒ-\\ﷇ\\ﷰ-\\﷽\\︀-\\︙\\︠-\\﹒\\﹔-\\﹦\\﹨-\\﹫\\ﹰ-\\ﹴ\\ﹶ-\\ﻼ\\！-\\ﾾ\\ￂ-\\ￇ\\ￊ-\\ￏ\\ￒ-\\ￗ\\ￚ-\\ￜ\\￠-\\￦\\￨-\\￮\\-\\�]*$' (HTTP 400) (Request-ID: req-XXX)
~~~

The same description doesn't cause a failure on volume creation operation.

Version-Release number of selected component (if applicable):
Current upstream and downstream cinder.

How reproducible:
Everytime when a user run the command.

Steps to Reproduce:
1. Create a volume.
2. Create a snapshot with the description which contains a new line character like
~~~
$ openstack volume snapshot create --volume cirros_boot --description "test with new line <press enter key to insert the new line character>
character for snapshot volume" test_snapshot
~~~

Actual results:
The request is failed as HTTP Code:400.

Expected results:
The request is succeeded like a volume creation.

Additional info:
In my preliminary research, the difference between volume creation and snapshot creation comes from the schema validation.

For volume creation, the schema validation is specified as
~~~
create = {
    'type': 'object',
    'properties': {
        'volume': {
            'type': 'object',
            'properties': {
                'name': {'type': ['string', 'null'],
                         'format': 'name_non_mandatory_remove_white_spaces'},
                'description': {
                    'type': ['string', 'null'],
                    'format': 'description_non_mandatory_remove_white_spaces'},
                'display_name': {
                    'type': ['string', 'null'],
                    'format': 'name_non_mandatory_remove_white_spaces'},
                'display_description': {
                    'type': ['string', 'null'],
                    'format':
                        'description_non_mandatory_remove_white_spaces'},
:
}
~~~

On the other hand, the schema validation for snapshot is defined as
~~~
valid_description_regex_base = '^[%s]*$'

valid_description_regex = valid_description_regex_base % (
    _build_regex_range())

description = {
    'type': ['string', 'null'], 'minLength': 0, 'maxLength': 255,
    'pattern': valid_description_regex,
}

create = {
    'type': 'object',
    'properties': {
        'type': 'object',
        'snapshot': {
            'type': 'object',
            'properties': {
                'name': parameter_types.name_allow_zero_min_length,
                'display_name': parameter_types.name_allow_zero_min_length,
                'description': parameter_types.description,
                'volume_id': parameter_types.uuid_allow_null,
                'force': parameter_types.boolean,
                'metadata': parameter_types.metadata_allows_null,
            },
            'required': ['volume_id'],
            'additionalProperties': False,
        },
    },
    'required': ['snapshot'],
    'additionalProperties': False,
}
~~~

In cinder, description field for volume and snapshot are defined as the same data type,
~~~
class Volume(cleanable.CinderCleanableObject, base.CinderObject,
             base.CinderObjectDictCompat, base.CinderComparableObject,
             base.ClusteredObject):
:
    fields = {

        'display_description': fields.StringField(nullable=True),
~~~

~~~
class Snapshot(cleanable.CinderCleanableObject, base.CinderObject,
               base.CinderObjectDictCompat, base.CinderComparableObject,
               base.ClusteredObject):
:
    fields = {
:
        'display_description': fields.StringField(nullable=True),
~~~

In my opinion, there is no obvious reason why we implement the different validation methods between volume and snapshot for description field.