Fixes the following issues:
- If the channel update of FailFeeInsufficient contains an invalid channel
update, it is not possible to properly add to the failed channels set.
- FailAmountBelowMinimum may apply a channel update, but does not retry.
- FailIncorrectCltvExpiry immediately prunes the vertex without
trying one more time.
In this commit, the logic for all three policy related errors is
aligned.
Before this commit, if for example the linter failed, then we would go
on to all the other tests rather than halting. We fix this by instead
chaining the relevant commands, and eliminating the LINT env variable
in the build matrix.
In this commit, we add the ComputeInputScript which will allow callers
to obtain witnesses for all outputs under control of the wallet. This
allows external scripting of things like coin join, etc.
In this commit, we modify the existing rpcServer to fully manage the
macaroons, gRPC server, and also seek out and create all sub-servers.
With this change, the RPC server gains more responsibility, as it
becomes the "root" server in the hierarchy of gRPC sub-servers.
In addition to creating each sub-server, it will also merge the set of
macaroon permissions for each sub-server, with the permissions of the
rest of the RPC infra. As a result, each sub-server is able to
independently specify what it needs w.r.t macaroon permissions and have
that taken care of by the RPC server. In order to achieve this, we need
to unify the creation of the RPC interceptors, and also fully manage the
gRPC server ourselves.
Some examples with various build configs:
```
⛰i make build
Building debug lnd and lncli.
go build -v -tags="dev" -o lnd-debug -ldflags "-X github.com/lightningnetwork/lnd/build.Commit=v0.5-beta-143-gb2069914c4b76109b7c59320dc48f8a5f30deb75-dirty" github.com/lightningnetwork/lnd
go build -v -tags="dev" -o lncli-debug -ldflags "-X github.com/lightningnetwork/lnd/build.Commit=v0.5-beta-143-gb2069914c4b76109b7c59320dc48f8a5f30deb75-dirty" github.com/lightningnetwork/lnd/cmd/lncli
⛰i ./lnd-debug --debuglevel=debug --signrpc.signermacaroonpath=~/sign.macaroon
unknown flag `signrpc.signermacaroonpath'
unknown flag `signrpc.signermacaroonpath'
⛰i make build tags=signerrpc
Building debug lnd and lncli.
go build -v -tags="dev signerrpc" -o lnd-debug -ldflags "-X github.com/lightningnetwork/lnd/build.Commit=v0.5-beta-143-gb2069914c4b76109b7c59320dc48f8a5f30deb75-dirty" github.com/lightningnetwork/lnd
go build -v -tags="dev signerrpc" -o lncli-debug -ldflags "-X github.com/lightningnetwork/lnd/build.Commit=v0.5-beta-143-gb2069914c4b76109b7c59320dc48f8a5f30deb75-dirty" github.com/lightningnetwork/lnd/cmd/lncli
⛰i ./lnd-debug --debuglevel=debug --signrpc.signermacaroonpath=~/sign.macaroon
2018-10-22 17:31:01.132 [INF] LTND: Version: 0.5.0-beta commit=v0.5-beta-143-gb2069914c4b76109b7c59320dc48f8a5f30deb75-dirty, build=development, logging=default
2018-10-22 17:31:01.133 [INF] LTND: Active chain: Bitcoin (network=simnet)
2018-10-22 17:31:01.140 [INF] CHDB: Checking for schema update: latest_version=6, db_version=6
2018-10-22 17:31:01.236 [INF] LTND: Primary chain is set to: bitcoin
2018-10-22 17:31:02.391 [INF] LNWL: Opened wallet
2018-10-22 17:31:03.315 [INF] LNWL: The wallet has been unlocked without a time limit
2018-10-22 17:31:03.315 [INF] LTND: LightningWallet opened
2018-10-22 17:31:03.319 [INF] LNWL: Catching up block hashes to height 3060, this will take a while...
2018-10-22 17:31:03.320 [INF] HSWC: Restoring in-memory circuit state from disk
2018-10-22 17:31:03.320 [INF] LNWL: Done catching up block hashes
2018-10-22 17:31:03.320 [INF] HSWC: Payment circuits loaded: num_pending=0, num_open=0
2018-10-22 17:31:03.322 [DBG] LTND: Populating dependencies for sub RPC server: Signrpc
```
As for the config, an example is:
```
[signrpc]
signrpc.signermacaroonpath=~/signer.macaroon
```
In this commit, we add the glue infrastructure to make the sub RPC
server system work properly. Our high level goal is the following: using
only the lnrpc package (with no visibility into the sub RPC servers),
the RPC server is able to find, create, run, and manage the entire set
of present and future sub RPC servers. In order to achieve this, we use
the reflect package and build tags heavily to permit a loosely coupled
configuration parsing system for the sub RPC servers.
We start with a new `subRpcServerConfigs` struct which is _always_
present. This struct has its own group, and will house a series of
sub-configs, one for each sub RPC server. Each sub-config is actually
gated behind a build flag, and can be used to allow users on the command
line or in the config to specify arguments related to the sub-server. If
the config isn't present, then we don't attempt to parse it at all, if
it is, then that means the RPC server has been registered, and we should
parse the contents of its config.
The `subRpcServerConfigs` struct has two main methods:
`PopulateDependancies` and `FetchConfig`. The `PopulateDependancies` is
used to dynamically locate and set the config fields for each new
sub-server. As the config may not actually have any fields (if the build
flag is off), we use the reflect pacakge to determine if things are
compiled in or not, then if so, we dynamically set each of the config
parameters. The `PopulateDependancies` method implements the
`lnrpc.SubServerConfigDispatcher` interface. Our goal is to allow sub
servers to look up their actual config in this main config struct. We
achieve this by using reflect to look up the target field _as if it were
a key in a map_. If the field is found, then we check if it has any
actual attributes (it won't if the build flag is off), if it is, then we
return it as we expect it to be populated already.
