Checklist

• My issue is specific & actionable.
• I am not suggesting a protocol enhancement.
• I have searched on the issue tracker for my issue.

Description

Recently, Cloudflare has open sourced a fork of go-ipfs providing filtering capabilities, grouped under safemode command. The architecture is described in a dedicated blog.

The system works by filtering certain CID when walking the DAG. This allow node operators to prevent certain CID from being provided, both by the HTTP gateway and to the P2P network.
CIDs to be filtered are stored in a blocklist. By default, this blocklist is in a dedicated mount of the datastore /safemode.

Action that can be performed by a blocklist are (based on the proposed interface):

• block to add content to the blocklist
• unblock to remove it
• purge to remove content from the blockstore. Ideally, this option could be extensible, to purge remote datastore, or HTTP cache for instance
• search to query the blocklist
• audit to access the log of actions that have been performed against the blocklist

For convenience, ipfs safemode command provides multiple way to resolve content. From its documentation:

- IPFS address, i.e. /ipfs/<CID>
- IPNS address, i.e. /ipns/<hash_publickey>
- DNSLink address, i.e. /ipns/example.com
- HTTP URL, i.e. https://example.com/ or https://gateway.example.com/ipfs/<CID>

This is a proposal implementation, which satisfies some requirements laid out in ipfs/roadmap#64. It provides a more standardised approach for node operators to filter content they are willing to provide.

The implementation has been developed 3 years ago, and may not suit the current architecture of the go-ipfs project.