make+perms: allow itest to run with dev build tag

The dev flag allows us to enable some of lnd's configuration flags that
are only available for testing. To speed up any wallet interaction, we
also add the lowscrypt build tag that chooses weak encryption for the
wallet that is much faster (a couple of milliseconds vs. multiple
seconds per wallet creation).

Makefile

@@ -94,7 +94,7 @@ DOCKER_TOOLS = docker run \
   -v $(shell bash -c "mkdir -p /tmp/go-lint-cache; echo /tmp/go-lint-cache"):/root/.cache/golangci-lint \
   -v $$(pwd):/build litd-tools
 
-ITEST_TAGS := integration itest $(LND_RELEASE_TAGS)
+ITEST_TAGS := dev integration itest lowscrypt $(LND_RELEASE_TAGS)
 ITEST_LDFLAGS := $(call make_ldflags, $(ITEST_TAGS))
 
 GREEN := "\\033[0;32m"

perms/mock.go

@@ -1,3 +1,6 @@
+//go:build !dev
+// +build !dev
+
 package perms
 
 import (

perms/mock_dev.go

@@ -0,0 +1,94 @@
+//go:build dev
+// +build dev
+
+package perms
+
+import (
+	"net"
+
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/lightningnetwork/lnd/autopilot"
+	"github.com/lightningnetwork/lnd/chainreg"
+	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/lnrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/autopilotrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/chainrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/devrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/invoicesrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/neutrinorpc"
+	"github.com/lightningnetwork/lnd/lnrpc/peersrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/signrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/walletrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/watchtowerrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/wtclientrpc"
+	"github.com/lightningnetwork/lnd/lntest/mock"
+	"github.com/lightningnetwork/lnd/routing"
+	"github.com/lightningnetwork/lnd/sweep"
+)
+
+// mockConfig implements lnrpc.SubServerConfigDispatcher. It provides the
+// functionality required so that the lnrpc.GrpcHandler.CreateSubServer
+// function can be called without panicking.
+type mockConfig struct{}
+
+var _ lnrpc.SubServerConfigDispatcher = (*mockConfig)(nil)
+
+// FetchConfig is a mock implementation of lnrpc.SubServerConfigDispatcher. It
+// is used as a parameter to lnrpc.GrpcHandler.CreateSubServer and allows the
+// function to be called without panicking. This is useful because
+// CreateSubServer can be used to extract the permissions required by each
+// registered subserver.
+//
+// TODO(elle): remove this once the sub-server permission lists in LND have been
+// exported
+func (t *mockConfig) FetchConfig(subServerName string) (interface{}, bool) {
+	switch subServerName {
+	case "InvoicesRPC":
+		return &invoicesrpc.Config{}, true
+	case "WatchtowerClientRPC":
+		return &wtclientrpc.Config{
+			Resolver: func(_, _ string) (*net.TCPAddr, error) {
+				return nil, nil
+			},
+		}, true
+	case "AutopilotRPC":
+		return &autopilotrpc.Config{
+			Manager: &autopilot.Manager{},
+		}, true
+	case "ChainRPC":
+		return &chainrpc.Config{
+			ChainNotifier: &chainreg.NoChainBackend{},
+			Chain:         &mock.ChainIO{},
+		}, true
+	case "DevRPC":
+		return &devrpc.Config{
+			ActiveNetParams: &chaincfg.RegressionNetParams,
+			GraphDB:         &channeldb.ChannelGraph{},
+		}, true
+	case "NeutrinoKitRPC":
+		return &neutrinorpc.Config{}, true
+	case "PeersRPC":
+		return &peersrpc.Config{}, true
+	case "RouterRPC":
+		return &routerrpc.Config{
+			Router: &routing.ChannelRouter{},
+		}, true
+	case "SignRPC":
+		return &signrpc.Config{
+			Signer: &mock.DummySigner{},
+		}, true
+	case "WalletKitRPC":
+		return &walletrpc.Config{
+			FeeEstimator: &chainreg.NoChainBackend{},
+			Wallet:       &mock.WalletController{},
+			KeyRing:      &mock.SecretKeyRing{},
+			Sweeper:      &sweep.UtxoSweeper{},
+			Chain:        &mock.ChainIO{},
+		}, true
+	case "WatchtowerRPC":
+		return &watchtowerrpc.Config{}, true
+	default:
+		return nil, false
+	}
+}