devrpc: add read-only FetchReputation RPC

Expose the local reputation subsystem's computed state through a new unary,
read-only FetchReputation method on the devrpc (dev/debug) sub-server. The
handler calls Manager.Snapshot() and marshals the per-channel state into the
new ChannelReputation / BucketOccupancy proto messages.

The reputation manager is wired into the devrpc Config through
PopulateDependencies. It is nil unless the experimental --routing.reputation
flag is set; the handler is nil-safe and returns a clear "reputation
subsystem disabled" error in that case. The method requires a read-only
offchain macaroon permission, and an lncli "fetchreputation" command and a
harness RPC wrapper are added to drive it.

Generated proto stubs regenerated via 'make rpc' (docker-based gen_protos).

Author: GeorgeTsagk

cmd/commands/devrpc_active.go

@@ -24,6 +24,16 @@ func devCommands() []cli.Command {
 			ArgsUsage:   "graph-json-file",
 			Action:      actionDecorator(importGraph),
 		},
+		{
+			Name:     "fetchreputation",
+			Category: "Development",
+			Description: "Fetches a read-only snapshot of the " +
+				"local reputation subsystem's computed " +
+				"per-channel state. Requires the node to be " +
+				"running with --routing.reputation.",
+			Usage:  "Fetch the local reputation snapshot.",
+			Action: actionDecorator(fetchReputation),
+		},
 	}
 }
 
@@ -60,3 +70,20 @@ func importGraph(ctx *cli.Context) error {
 	printRespJSON(res)
 	return nil
 }
+
+func fetchReputation(ctx *cli.Context) error {
+	ctxc := getContext()
+	client, cleanUp := getDevClient(ctx)
+	defer cleanUp()
+
+	res, err := client.FetchReputation(
+		ctxc, &devrpc.FetchReputationRequest{},
+	)
+	if err != nil {
+		return err
+	}
+
+	printRespJSON(res)
+
+	return nil
+}

lnrpc/devrpc/config_active.go

@@ -7,6 +7,7 @@ import (
 	"github.com/btcsuite/btcd/chaincfg"
 	graphdb "github.com/lightningnetwork/lnd/graph/db"
 	"github.com/lightningnetwork/lnd/htlcswitch"
+	"github.com/lightningnetwork/lnd/reputation"
 )
 
 // Config is the primary configuration struct for the DEV RPC server. It
@@ -18,4 +19,10 @@ type Config struct {
 	ActiveNetParams *chaincfg.Params
 	GraphDB         *graphdb.ChannelGraph
 	Switch          *htlcswitch.Switch
+
+	// ReputationManager is the optional read-only local reputation
+	// subsystem. It is nil unless the experimental --routing.reputation
+	// flag is set; the FetchReputation RPC returns a clear error when it is
+	// nil.
+	ReputationManager *reputation.Manager
 }