From 1bc25c1136c7c5a076f9078e5f0b29ab705af05f Mon Sep 17 00:00:00 2001
From: Boris Nagaev <bnagaev@gmail.com>
Date: Mon, 18 Nov 2024 11:17:02 -0300
Subject: [PATCH 1/3] config: fix "lnd --debuglevel show" command

Previously, "lnd --debuglevel show" complained that bitcoin backend is not
configured:

$ lnd --debuglevel show
failed to load config: ValidateConfig: either --bitcoin.mainnet, or ...

To make it working, the user had to specify --bitcoin.mainnet and configure one
of the backends, e.g. "--bitcoin.node neutrino".

With this fix, the command works without any additional flags.
---
 config.go | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/config.go b/config.go
index dc9a1453c..fa2575d28 100644
--- a/config.go
+++ b/config.go
@@ -860,6 +860,18 @@ func LoadConfig(interceptor signal.Interceptor) (*Config, error) {
 func ValidateConfig(cfg Config, interceptor signal.Interceptor, fileParser,
 	flagParser *flags.Parser) (*Config, error) {
 
+	// Special show command to list supported subsystems and exit.
+	if cfg.DebugLevel == "show" {
+		subLogMgr := build.NewSubLoggerManager()
+
+		// Initialize logging at the default logging level.
+		SetupLoggers(subLogMgr, interceptor)
+
+		fmt.Println("Supported subsystems",
+			subLogMgr.SupportedSubsystems())
+		os.Exit(0)
+	}
+
 	// If the provided lnd directory is not the default, we'll modify the
 	// path to all of the files and directories that will live within it.
 	lndDir := CleanAndExpandPath(cfg.LndDir)
@@ -1408,13 +1420,6 @@ func ValidateConfig(cfg Config, interceptor signal.Interceptor, fileParser,
 	// Initialize logging at the default logging level.
 	SetupLoggers(cfg.SubLogMgr, interceptor)
 
-	// Special show command to list supported subsystems and exit.
-	if cfg.DebugLevel == "show" {
-		fmt.Println("Supported subsystems",
-			cfg.SubLogMgr.SupportedSubsystems())
-		os.Exit(0)
-	}
-
 	if cfg.MaxLogFiles != 0 {
 		if cfg.LogConfig.File.MaxLogFiles !=
 			build.DefaultMaxLogFiles {

From 3360d285fbec15e558f0af65ab3c8439558be40a Mon Sep 17 00:00:00 2001
From: Boris Nagaev <bnagaev@gmail.com>
Date: Mon, 18 Nov 2024 11:24:16 -0300
Subject: [PATCH 2/3] config: improve error message

Previously, the error message had one missing space:
"... either --bitcoin.mainnet, or bitcoin.testnet,bitcoin.simnet, ..."

I added a space after "bitcoin.testnet,".
---
 config.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config.go b/config.go
index fa2575d28..04a491765 100644
--- a/config.go
+++ b/config.go
@@ -1261,7 +1261,7 @@ func ValidateConfig(cfg Config, interceptor signal.Interceptor, fileParser,
 	// The target network must be provided, otherwise, we won't
 	// know how to initialize the daemon.
 	if numNets == 0 {
-		str := "either --bitcoin.mainnet, or bitcoin.testnet," +
+		str := "either --bitcoin.mainnet, or bitcoin.testnet, " +
 			"bitcoin.simnet, bitcoin.regtest or bitcoin.signet " +
 			"must be specified"
 

From 64c660c19e806a019e19079f4367ecec87cb85b8 Mon Sep 17 00:00:00 2001
From: Boris Nagaev <bnagaev@gmail.com>
Date: Mon, 18 Nov 2024 12:15:00 -0300
Subject: [PATCH 3/3] itest: test "lnd --debuglevel=show" command

Tests that "lnd --debuglevel=show" command works and prints the list of
supported subsystems.
---
 itest/config.go       | 28 ++++++++++++++++++++++++++++
 itest/list_on_test.go |  4 ++++
 2 files changed, 32 insertions(+)
 create mode 100644 itest/config.go

diff --git a/itest/config.go b/itest/config.go
new file mode 100644
index 000000000..98e633652
--- /dev/null
+++ b/itest/config.go
@@ -0,0 +1,28 @@
+//go:build integration
+
+package itest
+
+import (
+	"os/exec"
+
+	"github.com/lightningnetwork/lnd/lntest"
+	"github.com/stretchr/testify/require"
+)
+
+// testDebuglevelShow tests that "lnd --debuglevel=show" command works and
+// prints the list of supported subsystems.
+func testDebuglevelShow(ht *lntest.HarnessTest) {
+	// We can't use ht.NewNode, because it adds more arguments to the
+	// command line (e.g. flags configuring bitcoin backend), but we want to
+	// make sure that "lnd --debuglevel=show" works without any other flags.
+	lndBinary := getLndBinary(ht.T)
+	cmd := exec.Command(lndBinary, "--debuglevel=show")
+	stdoutStderrBytes, err := cmd.CombinedOutput()
+	require.NoError(ht, err, "failed to run 'lnd --debuglevel=show'")
+
+	// Make sure that the output contains the list of supported subsystems
+	// and that the list is not empty. We search PEER subsystem.
+	stdoutStderr := string(stdoutStderrBytes)
+	require.Contains(ht, stdoutStderr, "Supported subsystems")
+	require.Contains(ht, stdoutStderr, "PEER")
+}
diff --git a/itest/list_on_test.go b/itest/list_on_test.go
index c5fa7cebf..68c923c3b 100644
--- a/itest/list_on_test.go
+++ b/itest/list_on_test.go
@@ -702,4 +702,8 @@ var allTestCases = []*lntest.TestCase{
 		Name:     "send to route failed htlc timeout",
 		TestFunc: testSendToRouteFailHTLCTimeout,
 	},
+	{
+		Name:     "debuglevel show",
+		TestFunc: testDebuglevelShow,
+	},
 }