[NC | DBS3] Add support for reserved bucket tags

[tangledbytes]

Explain the Changes

This PR adds the concept of "reserved" bucket tags which are bucket tags which can be set via noobaa cli or via put-bucket-tagging but they can come with further restrictions like a schema, immutability, etc.

DBS3 Example:

// In config-local.js or in config.json
config.NSFS_GLACIER_RESERVED_BUCKET_TAGS = {
    'deep-archive-copies': {
        schema: {
            $id: 'deep-archive-copies-schema-v0',
            enum: ['1', '2']
        }, // JSON Schema
        immutable: 'if-data',
        default: '1',
        event: true,
    }
}

Usage Example:

$ noobaa-cli bucket update --tag '[{ "key": "k1", "value": "v1" }]' ...
$ noobaa-cli bucket update --merge_tag '[{ "key": "k1", "value": "v1" }]' ...
$ aws s3api put-bucket-tagging TagSet=[{Key=deep-archive-copies,Value=2}]'

Issues: Fixed #xxx / Gap #xxx

Testing Instructions:

• Doc added/updated
• Tests added

[shirady]

I think it is a bit confusing, suggesting to change it to:

Suggested change

	const bucket_empty = await _is_bucket_empty(data);
	const is_bucket_empty = await empty_bucket(data);

From what I understand the operation is to empty the bucket and return true when it ends.

[shirady]

Why do you pass null as the params?

[tangledbytes]

Because I wanted to not provide and params in this case.

undefined vs null - this is quite opinionated. I prefer using null over undefined when I intentionally want to have a zero value. It helps me tell when the zero value was intentional and when the zero value is system generated.

I am aware that Guy disagrees with this opinion as null is an object.

[shirady]

versioning is a property of the bucket, I think you can check if the bucket versioning is disabled in a simpler way.

noobaa-core/src/server/system_services/schemas/nsfs_bucket_schema.js

Lines 48 to 49 in 779c0bf

	versioning: {
	$ref: 'common_api#/definitions/versioning',

[tangledbytes]

I wanted to keep the check consistent with the rest of bucketspace_fs.

[shirady]

Is this code used more than once?
We can move it to a function and reuse it.

[tangledbytes]

It is I think but don't think its worth moving these lines into a new function. This code is concise enough, wdyt?

[shirady]

@tangledbytes some general comments / questions:

• Could you update the NC NSFS docs with the new change?
• Could you add testing instructions and automated tests for the code changes? (especially on the reserved case)
• Does it mean that now every bucket would have the property tag in it? Do we need to consider upgrade changes for older buckets?