Fix LND-based sanity tests

[bonomat]

Follow-up ticket of #2106

Problem

This PR introduces skips LND sanity issues. This should not be the case.
It currently timeout at genSeed phase, sometimes it works.

• lnd is slow to catch-up with blocks from wallet initialisation
• 2 steps to init wallet: genSeed (to generate seed words) and then initWallet using the previous seed.
• genSeed accepts a byte array as entropy, this can be pseudo random to not use as much entropy on the local machine.

Goal

Have a stable and preferable fast (parallelizable) LN e2e test setup.

Recommendation

• Start LND nodes in the test setup not within the tests so that they can be shared between tests.

[bonomat]

Different idea:

I looked into this issue and I find it really hard to debug. Given we want to move to a complete different setup (start blockchain nodes before the tests #2191) I would propose to ditch the current lnd setup in our e2e tests and start from scratch.

To simplify the setup, we could also move to a simple docker setup, e.g. use the provided containers from here: https://github.com/lightningnetwork/lnd/tree/master/docker
Note: haven't checked if they have holdinvoice enabled)

We don't necessarily have to use the same bitcoin nodes for other e2e tests and the lnd-based e2e tests.

@D4nte : what do you think?

[D4nte]

Different idea:

I looked into this issue and I find it really hard to debug. Given we want to move to a complete different setup (start blockchain nodes before the tests #2191) I would propose to ditch the current lnd setup in our e2e tests and start from scratch.

To simplify the setup, we could also move to a simple docker setup, e.g. use the provided containers from here: lightningnetwork/lnd:docker@master

We don't necessarily have to use the same bitcoin nodes for other e2e tests and the lnd-based e2e tests.

@D4nte : what do you think?

Yes I support move to docker for lnd & bitcoind just for lnd tests.

[thomaseizinger]

Different idea:
I looked into this issue and I find it really hard to debug. Given we want to move to a complete different setup (start blockchain nodes before the tests #2191) I would propose to ditch the current lnd setup in our e2e tests and start from scratch.
To simplify the setup, we could also move to a simple docker setup, e.g. use the provided containers from here: lightningnetwork/lnd:docker@master
We don't necessarily have to use the same bitcoin nodes for other e2e tests and the lnd-based e2e tests.
@D4nte : what do you think?

Yes I support move to docker for lnd & bitcoind just for lnd tests.

How is that going to make a difference?
We are not experiencing problems in the interaction between bitcoind and lnd right?

[thomaseizinger]

Do you want me to put this issue on hold and we define a different approach?

[bonomat]

How is that going to make a difference?

it simplifies the setup and maybe it's time to admit that running bare-metal nodes was not the best move.

We are not experiencing problems in the interaction between bitcoind and lnd right?

I'm not sure about this. That's what I meant with the first part:

I would propose to ditch the current lnd setup

because I really don't have an idea where the problem is.

So, my proposal for this ticket which is about fixing lnd-based sanity tests:

Ditch the current lnd setup and start from scratch (potentially by using docker containers)

[thomaseizinger]

Okay, I understand.

I did not yet spend any time on it today. I will time-box the rest of the day to see if I can get it working. If not, I am happy to go for a different approach / drop the ticket.