Reduce some logspam.

ipn/local.go

@@ -226,7 +226,10 @@ func (b *LocalBackend) Start(opts Options) error {
 			if b.netMapCache != nil && b.cmpDiff != nil {
 				s1 := strings.Split(b.netMapCache.Concise(), "\n")
 				s2 := strings.Split(newSt.NetMap.Concise(), "\n")
-				b.logf("netmap diff:\n%v\n", b.cmpDiff(s1, s2))
+				diff := b.cmpDiff(s1, s2)
+				if strings.TrimSpace(diff) != "" {
+					b.logf("netmap diff:\n%v\n", diff)
+				}
 			}
 			b.netMapCache = newSt.NetMap
 			b.mu.Unlock()

wgengine/userspace.go

@@ -353,8 +353,6 @@ func (e *userspaceEngine) Reconfig(cfg *wgcfg.Config, dnsDomains []string) error
 		DNS:        cfg.DNS,
 		DNSDomains: dnsDomains,
 	}
-	e.logf("Reconfiguring router. la=%v dns=%v dom=%v\n",
-		rs.LocalAddr, rs.DNS, rs.DNSDomains)
 
 	// TODO(apenwarr): all the parts of RouteSettings should be "relevant."
 	// We're checking only the "relevant" parts to see if they have
@@ -364,16 +362,19 @@ func (e *userspaceEngine) Reconfig(cfg *wgcfg.Config, dnsDomains []string) error
 	// a whole Cfg object as part of RouteSettings; instead, trim it to
 	// just what's absolutely needed (the set of actual routes).
 	rss := rs.OnlyRelevantParts()
-	e.logf("New routes: %v\n", rss)
-	if rss == e.lastRoutes {
-		e.logf("...unchanged routes, skipping.\n")
-		return nil
-	}
+	if rss != e.lastRoutes {
+		e.logf("Reconfiguring router. la=%v dns=%v dom=%v; new routes: %v\n",
+			rs.LocalAddr, rs.DNS, rs.DNSDomains, rss)
 		e.lastRoutes = rss
 		err = e.router.SetRoutes(rs)
-	e.logf("Reconfig() done.\n")
+		if err != nil {
 			return err
 		}
+	}
+
+	e.logf("Reconfig() done.\n")
+	return nil
+}
 
 func (e *userspaceEngine) SetFilter(filt *filter.Filter) {
 	var filtin, filtout func(b []byte) device.FilterResult