[COUCHDB-2960] Support RFC 7725 (HTTP 451)

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Component/s: Database Core, HTTP Interface
• Assignee: Unassigned
• Reporter: Alexander Shorin
• Created: 04/Mar/16 08:14
• Updated: 02/Sep/18 07:07
• Resolved: 02/Sep/18 07:07

Description

Recently HTTP 451 response status code was made as a standard one. Due to global trends on Internet filtration and censorship, I think we should support this initiative.

Proposal:
1. Trivial. Let 451 response status get counted by stats. So users may return {code: 451, body: 'sorry, DMCA'} and these will be counted correctly. How they will decide when to 451 and when to not it's up to user implementation.

2. Advanced. Introduce new special field like _down_by_legal_reason (bikeshedding) which is an object and contains the reason why and reference to the blocking statement. Like:

{
  "_id": "Game of Thrones",
  "_attachments": {
    "S4E01": {...}
  },
  "_down_by_legal_reasons": {
    "link": "http://somewhere.else/issue/123",
    "reason": "Piracy is bad",
  },
  "type": "serial",
}

The data from a link subfield goes to Link response header as RFC suggests. Documents with _down_by_legal_reason field cannot be browsed by regular users, only admins may work with them. Additionally we can make them non-replicable, but I don't think that you want to run replication using db admin credentials by security reasons.