From 7b629fcbe0fcd9c5e2c36abbb43164306a9a6984 Mon Sep 17 00:00:00 2001
From: rosstimothy <39066650+rosstimothy@users.noreply.github.com>
Date: Tue, 19 Nov 2024 12:18:54 -0500
Subject: [PATCH] Extend hostid test backoff (#49193)

Attempts to reduce any flakiness caused by contention producing a
host id by allowing tests to use a longer exponential backoff and
retrying more times.
---
 lib/utils/hostid/hostid_test.go | 13 ++++++++-
 lib/utils/hostid/hostid_unix.go | 51 ++++++++++++++++++++++++++-------
 2 files changed, 52 insertions(+), 12 deletions(-)

diff --git a/lib/utils/hostid/hostid_test.go b/lib/utils/hostid/hostid_test.go
index 2ea22c4e71e7f..62073f1c44a63 100644
--- a/lib/utils/hostid/hostid_test.go
+++ b/lib/utils/hostid/hostid_test.go
@@ -24,12 +24,14 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"golang.org/x/sync/errgroup"
 
+	"github.com/gravitational/teleport/api/utils/retryutils"
 	"github.com/gravitational/teleport/lib/utils"
 	"github.com/gravitational/teleport/lib/utils/hostid"
 )
@@ -53,7 +55,16 @@ func TestReadOrCreate(t *testing.T) {
 		i := i
 		wg.Go(func() error {
 			<-barrier
-			id, err := hostid.ReadOrCreateFile(dir)
+			id, err := hostid.ReadOrCreateFile(
+				dir,
+				hostid.WithBackoff(retryutils.RetryV2Config{
+					First:  50 * time.Millisecond,
+					Driver: retryutils.NewExponentialDriver(100 * time.Millisecond),
+					Max:    15 * time.Second,
+					Jitter: retryutils.FullJitter,
+				}),
+				hostid.WithIterationLimit(10),
+			)
 			ids[i] = id
 			return err
 		})
diff --git a/lib/utils/hostid/hostid_unix.go b/lib/utils/hostid/hostid_unix.go
index df91eec76b83d..73b51a0dc537d 100644
--- a/lib/utils/hostid/hostid_unix.go
+++ b/lib/utils/hostid/hostid_unix.go
@@ -44,23 +44,52 @@ func WriteFile(dataDir string, id string) error {
 	return nil
 }
 
+type options struct {
+	retryConfig    retryutils.RetryV2Config
+	iterationLimit int
+}
+
+// WithBackoff overrides the default backoff configuration of
+// [ReadOrCreateFile].
+func WithBackoff(cfg retryutils.RetryV2Config) func(*options) {
+	return func(o *options) {
+		o.retryConfig = cfg
+	}
+}
+
+// WithIterationLimit overrides the default number of time
+// [ReadOrCreateFile] will attempt to produce a hostid.
+func WithIterationLimit(limit int) func(*options) {
+	return func(o *options) {
+		o.iterationLimit = limit
+	}
+}
+
 // ReadOrCreateFile looks for a hostid file in the data dir. If present,
-// returns the UUID from it, otherwise generates one
-func ReadOrCreateFile(dataDir string) (string, error) {
+// returns the UUID from it, otherwise generates one.
+func ReadOrCreateFile(dataDir string, opts ...func(*options)) (string, error) {
+	o := options{
+		retryConfig: retryutils.RetryV2Config{
+			First:  100 * time.Millisecond,
+			Driver: retryutils.NewLinearDriver(100 * time.Millisecond),
+			Max:    time.Second,
+			Jitter: retryutils.NewFullJitter,
+		},
+		iterationLimit: 3,
+	}
+
+	for _, opt := range opts {
+		opt(&o)
+	}
+
 	hostUUIDFileLock := GetPath(dataDir) + ".lock"
-	const iterationLimit = 3
-
-	backoff, err := retryutils.NewRetryV2(retryutils.RetryV2Config{
-		First:  100 * time.Millisecond,
-		Driver: retryutils.NewLinearDriver(100 * time.Millisecond),
-		Max:    time.Second,
-		Jitter: retryutils.NewFullJitter(),
-	})
+
+	backoff, err := retryutils.NewRetryV2(o.retryConfig)
 	if err != nil {
 		return "", trace.Wrap(err)
 	}
 
-	for i := 0; i < iterationLimit; i++ {
+	for i := 0; i < o.iterationLimit; i++ {
 		if read, err := ReadFile(dataDir); err == nil {
 			return read, nil
 		} else if !trace.IsNotFound(err) {