I propose we add support for running ipfs daemon with optional --agent-version-suffix= parameter.

This would enable vendors that bundle go-ipfs binary to customize AgentVersion (listed in ipfs id and announced to other peers) without the need for creating a fake libp2p protocol just to tell one cohort of go-ipfs nodes from another.

The first users of this would be Brave browser and IPFS Desktop:

• --agent-version-suffix=brave/1.19.85 → go-ipfs/0.9.0/brave/1.19.85
• --agent-version-suffix=desktop/0.14.0 → go-ipfs/0.9.0/desktop/0.14.0

Rationale

This would be opt-in, so does not introduce any new tracking vector, it simply aims to make things easier for vendors and to introduce common convention that preserves version number of go-ipfs.

In the current situation, where vendor can rebuild go-ipfs binary and change agentVersion, but then we lose information about % of different go-ipfs nodes on the DHT. By making it a suffix, and making it work without rebuild, we will decrease the number of opaque AgentVersions, making it easier for us to track upgrade dynamics etc.

CLI param, ENV or Config?

No preference atm – all will work for Brave.

• Config option would work fine
• Env variable IPFS_AGENT_VERSION_SUFFIX (similar to IPFS_PATH) is good enough too
• Explicit flag for ipfs daemon would be preferred, because it has added value if user has multiple go-ipfs nodes running on same localhost (eg. ipfs-desktop and brave). It enables things like ps aux | grep brave to quickly identify specific daemon instance.

cc @andrew @bbondy