add knots option

[Retropex]

• [x] That its based against the dev branch - not the default release branch.

This is not ready to merge, its to start receiving advice on what should I add/remove.

Close #4678

[rootzoll]

Hi thanks for the contribution. I am open to have alternative implementations to Bitcoin Core with RaspiBlitz as long as they are Interface compliant and dont need any changes on the rest of the code - as mentioned in #4678

So as far I can see @Retropex you are choosing to install Knots as an additional app - we now just have to look into all the details so that it can act as an in-place replacement for Bitcoin Core when activated. Its a bit like hotswapping an engine of a car, so there are some more things to care about.

On the top of my head we would need to check for the following:

• Does it use the same config file as Bitcoin Core ... because the user might altready made lots auf personal changes there he wants to see replected also with Bitcoin Knots?
• Does it take all the blockchain data, indexes, etc already build with Core or is there some reset/rebuilds needed?
• Does this all works also if users witch back to Bitcoin Core? Are additional Knots config values just get ignored by Core or does it need cleaning?

[Retropex]

The answer to the two first questions is yes, in fact knots have the exact same binary bitcoind so once retrieved and extracted my script stop bitcoin core delete the binary on put the of knots instead. so there is not a single difference for the others apps.

Regarding the specific settings of knots I don't know how core handle it, let me check.

[Retropex]

Ok just checked and core ignore knots settings 👍

[steepdawn974]

Suggestion: Perhaps add an echo section or example_bitcoin.conf with the additional Knots-specific options.

I've done something similar for nix-bitcoin https://github.com/steepdawn974/nix-bitcoin/commit/3f369f934eaf1bf62db9bbc9701d1ca264214429#diff-fdb5fc87f6d3166e0005897fbbf92421aff1fc346287914dcf528f779a6b8b2dR289

[xcarlitos]

Based on ongoing discussions around https://github.com/bitcoin/bitcoin/pull/32359, this one is needed more than ever! cc: @rootzoll, @Retropex

[satwise]

Please implement this ASAP given how the Bitcoin Core dev team have become bad actors lately that want Bitcoin to act like SCoins

[medigital-id]

Hope this can be the top priority and implement as soon as possible. I've tried to do it manually, it works, but somehow making some issues on the LND. I'm still beginner at this, but I want to move to knots sooner with clean setup. Thanks for your contribution @Retropex @rootzoll . Can't wait for this release.

[rootzoll]

Merging this PR for (internal) release candidate testing .. created issue #4996 with tasks still on my todo list regarding this feature.