Connect C-lightning to a remote bitcoind through tor

Question

I would like to connect my C-lightning node to a remote Bitcoin node, in order to be able to run lightningd on a small storage capacity VPS.

I could achieve this by using clearnet connection and wanted to know if would be possible to proxy the connection through the Tor network ?

Answer 1

Yes but not by default.

C-lightning uses a pluggable Bitcoin backend. The default one, bcli, will use the bitcoin-cli executable to make requests to a bitcoind.
It exposes bitcoin-cli's rpcconnect startup option to lightningd which does not not support onion hosts. And you probably don't want it to as it is not meant to be exposed.

If you want to run C-lightning without having the full block chain locally you'd probably opt for a light backend solution, such as:

• A pruned bitcoind (beware of misconfiguration)
• An explorer-backed backend.
  For example, the Sauron plugin which you could connect to an external Esplora instance you would run on a machine with more space. It supports onion services.

If you really want to remotely access bitcoind's RPC, you should probably opt for an SSH tunnel.