From aa740cb393c05e973400e05b7485cdda36181ce7 Mon Sep 17 00:00:00 2001
From: kari-ts <135075563+kari-ts@users.noreply.github.com>
Date: Fri, 24 Apr 2026 08:26:33 -0700
Subject: [PATCH] ipnlocal/drive: reduce noisey per-peer remote logs (#19493)

This drops the per peer "appending remote" log while constructing the remote list, which can get noisy on big tailnets, and keeps logs around remote availability checks, including whether a peer is missing, offline, lacks PeerAPI reachability, lacks sharing permission, or is available.

Updates tailscale/corp#40580

Signed-off-by: kari-ts <kari@tailscale.com>
---
 ipn/ipnlocal/drive.go | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/ipn/ipnlocal/drive.go b/ipn/ipnlocal/drive.go
index 485114eae..110ffff2a 100644
--- a/ipn/ipnlocal/drive.go
+++ b/ipn/ipnlocal/drive.go
@@ -303,18 +303,19 @@ func (b *LocalBackend) updateDrivePeersLocked(nm *netmap.NetworkMap) {
 }
 
 func (b *LocalBackend) driveRemotesFromPeers(nm *netmap.NetworkMap) []*drive.Remote {
-	b.logf("[v1] taildrive: setting up drive remotes from peers")
+	b.logf("[v1] taildrive: setting up drive remotes from %d peers", len(nm.Peers))
 	driveRemotes := make([]*drive.Remote, 0, len(nm.Peers))
 	for _, p := range nm.Peers {
 		peer := p
 		peerID := peer.ID()
 		peerKey := peer.Key().ShortString()
-		b.logf("[v1] taildrive: appending remote for peer %s", peerKey)
+		peerName := peer.DisplayName(false)
+
 		driveRemotes = append(driveRemotes, &drive.Remote{
-			Name: p.DisplayName(false),
+			Name: peerName,
 			URL: func() string {
 				url := fmt.Sprintf("%s/%s", b.currentNode().PeerAPIBase(peer), taildrivePrefix[1:])
-				b.logf("[v2] taildrive: url for peer %s: %s", peerKey, url)
+				b.logf("[v2] taildrive: url for peer %s (%s): %s", peerKey, peerName, url)
 				return url
 			},
 			Available: func() bool {
@@ -325,7 +326,7 @@ func (b *LocalBackend) driveRemotesFromPeers(nm *netmap.NetworkMap) []*drive.Rem
 				cn := b.currentNode()
 				peer, ok := cn.NodeByID(peerID)
 				if !ok {
-					b.logf("[v2] taildrive: Available(): peer %s not found", peerKey)
+					b.logf("[v2] taildrive: peer %s (%s, id=%v) not found", peerKey, peerName, peerID)
 					return false
 				}
 
@@ -338,26 +339,25 @@ func (b *LocalBackend) driveRemotesFromPeers(nm *netmap.NetworkMap) []*drive.Rem
 				// The netmap.Peers slice is not updated in all cases.
 				// It should be fixed now that we use PeerByIDOk.
 				if !peer.Online().Get() {
-					b.logf("[v2] taildrive: Available(): peer %s offline", peerKey)
+					b.logf("[v2] taildrive: peer %s (%s, id=%v) offline", peerKey, peerName, peerID)
 					return false
 				}
-
-				if b.currentNode().PeerAPIBase(peer) == "" {
-					b.logf("[v2] taildrive: Available(): peer %s PeerAPI unreachable", peerKey)
+				if cn.PeerAPIBase(peer) == "" {
+					b.logf("[v2] taildrive: peer %s (%s, id=%v) PeerAPI unreachable", peerKey, peerName, peerID)
 					return false
 				}
-
 				// Check that the peer is allowed to share with us.
 				if cn.PeerHasCap(peer, tailcfg.PeerCapabilityTaildriveSharer) {
-					b.logf("[v2] taildrive: Available(): peer %s available", peerKey)
+					b.logf("[v2] taildrive: peer %s (%s, id=%v) available", peerKey, peerName, peerID)
 					return true
 				}
 
-				b.logf("[v2] taildrive: Available(): peer %s not allowed to share", peerKey)
+				b.logf("[v2] taildrive: peer %s (%s, id=%v) not allowed to share", peerKey, peerName, peerID)
 				return false
 			},
 		})
 	}
+	b.logf("[v1] taildrive: built %d candidate remotes", len(driveRemotes))
 	return driveRemotes
 }