We add 'peer-level' rules to allow assessment of liquidity on a per-peer
level, rather than on an individual channel basis. No overlap is allowed
with the existing set of channel rules because this could lead to
contradictory rules.
This commit switches up our eligible channels logic to rather return
a struct containing information about our current swap traffic. This
change is made in preparation for returning reasons indicating why we
did not perform a swap for a specific channel - when we only return
eligible swaps, we lose the information about why all the excluded
channels weren't used.
In practice, this restriction has proven to be too strict. Autoloop will
now only hold off on a swap for a channel if a manual swap is
specifically using that channel.
In an effort to surface more information about why autoloop is not
executing, we add an error when suggest swaps is called with no rules.
In other cases we can surface a reason enum with each rule that is set,
but in the case where we have no rules, there are no results to
accompany with reasons.
To itest our autolooper, we need to be able to trigger dispatch on
demand. This functionality is included in a separate rpc server behind
a dev flag. Since it is unlikely that we need to split loop into
multiple rpc servers, this commit simply adds an additional debug server
rather than opting for a full subserver setup.
Add a dated fee budget to our swap suggestions. This budget only applies
to automatically dispatched swaps (which will be added in later
commits). We choose to apply the fee budget to our suggestions so that
they perfectly replicate what the autolooper would do. The budget has a
start date so that it can be refreshed once it has been used up over a
period (rather than having to endlessly increase it).
To decide whether we event want to attempt a swap, we add a fee limit
that we check against our estimate for the current number of
confirmations we want our sweep to confirm in. If fees are higher than
this limit, we do not suggest swaps.
This commit updates swap suggestions to return loop out requests with
sufficient fields populated so that a loop out can directly be
dispatched from a suggestion. This requires setting of fees an min
sweep conf targets (our htlc conf target and addresss will be set by
the daemon's client rpc server if we do not provide them). We also do
some test refactoring so that we can more easily test the suggest swaps
endpoint.
