fix: dnscache to re-use failed DNS lookups

go.mod

@@ -8,10 +8,10 @@ require (
 	github.com/gdamore/tcell/v2 v2.6.0
 	github.com/gorilla/mux v1.8.0
 	github.com/minio/cli v1.24.2
+	github.com/minio/dnscache v0.1.1
 	github.com/minio/pkg v1.6.5
 	github.com/prometheus/client_golang v1.15.0
 	github.com/rivo/tview v0.0.0-20230406072732-e22ce9588bb4
-	github.com/rs/dnscache v0.0.0-20211102005908-e0241e321417
 	github.com/sirupsen/logrus v1.9.0
 	go.uber.org/atomic v1.10.0
 	golang.org/x/sys v0.7.0

go.sum

@@ -49,6 +49,8 @@ github.com/matttproud/golang_protobuf_extensions v1.0.4 h1:mmDVorXM7PCGKw94cs5zk
 github.com/matttproud/golang_protobuf_extensions v1.0.4/go.mod h1:BSXmuO+STAnVfrANrmjBb36TMTDstsz7MSK+HVaYKv4=
 github.com/minio/cli v1.24.2 h1:J+fCUh9mhPLjN3Lj/YhklXvxj8mnyE/D6FpFduXJ2jg=
 github.com/minio/cli v1.24.2/go.mod h1:bYxnK0uS629N3Bq+AOZZ+6lwF77Sodk4+UL9vNuXhOY=
+github.com/minio/dnscache v0.1.1 h1:AMYLqomzskpORiUA1ciN9k7bZT1oB3YZN4cEIi88W5o=
+github.com/minio/dnscache v0.1.1/go.mod h1:WCumm6offO4rQ/82oTCSoHnlhTmc81+vXgKpBtSYRbg=
 github.com/minio/madmin-go/v2 v2.0.19 h1:XznxdMVCTyr0A88JrZFhdxWY8KLfJcrs0TTmFiE9cc8=
 github.com/minio/madmin-go/v2 v2.0.19/go.mod h1:8bL1RMNkblIENFSgGYjeHrzUx9PxROb7OqfNuMU9ivE=
 github.com/minio/md5-simd v1.1.2 h1:Gdi1DZK69+ZVMoNHRXJyNcxrMA4dSxoYHZSQbirFg34=
@@ -86,8 +88,6 @@ github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJ
 github.com/rivo/uniseg v0.4.3/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
 github.com/rivo/uniseg v0.4.4 h1:8TfxU8dW6PdqD27gjM8MVNuicgxIjxpm4K7x4jp8sis=
 github.com/rivo/uniseg v0.4.4/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
-github.com/rs/dnscache v0.0.0-20211102005908-e0241e321417 h1:Lt9DzQALzHoDwMBGJ6v8ObDPR0dzr2a6sXTB1Fq7IHs=
-github.com/rs/dnscache v0.0.0-20211102005908-e0241e321417/go.mod h1:qe5TWALJ8/a1Lqznoc5BDHpYX/8HU60Hm2AwRmqzxqA=
 github.com/rs/xid v1.5.0 h1:mKX4bl4iPYJtEIxp6CYiUuLQ/8DYMoz0PUdtGgMFRVc=
 github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
 github.com/secure-io/sio-go v0.3.1 h1:dNvY9awjabXTYGsTF1PiCySl9Ltofk9GA3VdWlo7rRc=

main.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2021-2022 MinIO, Inc.
+// Copyright (c) 2021-2023 MinIO, Inc.
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU Affero General Public License as published by
@@ -40,7 +40,7 @@ import (
 	"time"
 
 	"github.com/gorilla/mux"
-	"github.com/rs/dnscache"
+	"github.com/minio/dnscache"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/term"
 
@@ -82,22 +82,6 @@ var dnsCache = &dnscache.Resolver{
 func init() {
 	// Create a new instance of the logger. You can have any number of instances.
 	log2 = logrus.New()
-
-	options := dnscache.ResolverRefreshOptions{
-		ClearUnused:      true,
-		PersistOnFailure: false,
-	}
-
-	// Call to refresh will refresh names in cache. If you pass true, it will also
-	// remove cached names not looked up since the last call to Refresh. It is a good idea
-	// to call this method on a regular interval.
-	go func() {
-		t := time.NewTicker(30 * time.Second)
-		defer t.Stop()
-		for range t.C {
-			dnsCache.RefreshWithOptions(options)
-		}
-	}()
 }
 
 func logMsg(msg logMessage) error {
@@ -809,6 +793,15 @@ func sidekickMain(ctx *cli.Context) {
 	globalConsoleDisplay = globalLoggingEnabled || ctx.IsSet("trace") || !term.IsTerminal(int(os.Stdout.Fd()))
 	globalDebugEnabled = ctx.GlobalBool("debug")
 
+	go func() {
+		t := time.NewTicker(ctx.GlobalDuration("dns-ttl"))
+		defer t.Stop()
+
+		for range t.C {
+			dnsCache.Refresh()
+		}
+	}()
+
 	if !strings.HasPrefix(healthCheckPath, slashSeparator) {
 		healthCheckPath = slashSeparator + healthCheckPath
 	}
@@ -875,7 +868,7 @@ func main() {
 	app.Description = `High-Performance sidecar load-balancer`
 	app.UsageText = "[FLAGS] SITE1 [SITE2..]"
 	app.Version = version
-	app.Copyright = "(c) 2020-2021 MinIO, Inc."
+	app.Copyright = "(c) 2020-2023 MinIO, Inc."
 	app.Flags = []cli.Flag{
 		cli.StringFlag{
 			Name:  "address, a",
@@ -948,6 +941,11 @@ func main() {
 			Name:  "pprof",
 			Usage: "start and listen for profiling on the specified address (e.g. `:1337`)",
 		},
+		cli.DurationFlag{
+			Name:  "dns-ttl",
+			Usage: "choose custom DNS TTL value for DNS refreshes for load balanced endpoints",
+			Value: 10 * time.Minute,
+		},
 	}
 	app.CustomAppHelpTemplate = `NAME:
   {{.Name}} - {{.Description}}