Make invoicer not generate an invoice if LND is not ready

[nolim1t]

Just to make things more robust If synced_to_chain is false (usually after a LND restart) it should return a response saying it can't generate an invoice rather than hanging

[meeDamian]

The issue is the call to getinfo can sometimes take a few seconds (for so for undetermined reasons), and if I were to call it prior to every invoice generation call, it can slow it down significantly :/

But I agree it needs to be addressed somehow.

[nolim1t]

Maybe outsource it to the healthcheck endpoint. There may be uses for that still, but have the front end do some checks

[meeDamian]

After putting some thought into it, I think it makes sense to have a goroutine calling lnd periodically, and:

If call worked, but now fails: suicide
If call returns not synced to chain tip: block API with some "not ready" error
If call worked, and synced to chain tip: remove the block.