From f0d58cdda7280b0b046985039a7ac55135f074a7 Mon Sep 17 00:00:00 2001
From: Darko Draskovic <darko.draskovic@harness.io>
Date: Thu, 28 Nov 2024 18:19:12 +0000
Subject: [PATCH] fix: [CODE-2833]: Ignore Redis related cache errors when
 get/set key (#3059)

* Ignore Redis related cache errors when get/set key
---
 cache/redis_cache.go         | 13 +++++++++----
 git/api/last_commit_cache.go |  9 ++++++++-
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/cache/redis_cache.go b/cache/redis_cache.go
index d0b4a5bd2..d91914fdf 100644
--- a/cache/redis_cache.go
+++ b/cache/redis_cache.go
@@ -23,6 +23,8 @@ import (
 	"github.com/go-redis/redis/v8"
 )
 
+type LogErrFn func(context.Context, error)
+
 type Redis[K any, V any] struct {
 	client     redis.UniversalClient
 	duration   time.Duration
@@ -31,6 +33,7 @@ type Redis[K any, V any] struct {
 	codec      Codec[V]
 	countHit   int64
 	countMiss  int64
+	logErrFn   LogErrFn
 }
 
 type Encoder[V any] interface {
@@ -52,6 +55,7 @@ func NewRedis[K any, V any](
 	keyEncoder func(K) string,
 	codec Codec[V],
 	duration time.Duration,
+	logErrFn LogErrFn,
 ) *Redis[K, V] {
 	return &Redis[K, V]{
 		client:     client,
@@ -61,6 +65,7 @@ func NewRedis[K any, V any](
 		codec:      codec,
 		countHit:   0,
 		countMiss:  0,
+		logErrFn:   logErrFn,
 	}
 }
 
@@ -82,8 +87,8 @@ func (c *Redis[K, V]) Get(ctx context.Context, key K) (V, error) {
 			c.countHit++
 			return value, nil
 		}
-	} else if !errors.Is(err, redis.Nil) {
-		return nothing, err
+	} else if !errors.Is(err, redis.Nil) && c.logErrFn != nil {
+		c.logErrFn(ctx, err)
 	}
 
 	c.countMiss++
@@ -94,8 +99,8 @@ func (c *Redis[K, V]) Get(ctx context.Context, key K) (V, error) {
 	}
 
 	err = c.client.Set(ctx, strKey, c.codec.Encode(item), c.duration).Err()
-	if err != nil {
-		return nothing, err
+	if err != nil && c.logErrFn != nil {
+		c.logErrFn(ctx, err)
 	}
 
 	return item, nil
diff --git a/git/api/last_commit_cache.go b/git/api/last_commit_cache.go
index e7cc66582..55e29fcdf 100644
--- a/git/api/last_commit_cache.go
+++ b/git/api/last_commit_cache.go
@@ -28,6 +28,7 @@ import (
 	"github.com/harness/gitness/git/sha"
 
 	"github.com/go-redis/redis/v8"
+	"github.com/rs/zerolog/log"
 )
 
 func NewInMemoryLastCommitCache(
@@ -38,6 +39,10 @@ func NewInMemoryLastCommitCache(
 		cacheDuration)
 }
 
+func logCacheErrFn(ctx context.Context, err error) {
+	log.Ctx(ctx).Warn().Msgf("failed to use cache: %s", err.Error())
+}
+
 func NewRedisLastCommitCache(
 	redisClient redis.UniversalClient,
 	cacheDuration time.Duration,
@@ -55,7 +60,9 @@ func NewRedisLastCommitCache(
 			return "last_commit:" + hex.EncodeToString(h.Sum(nil))
 		},
 		commitValueCodec{},
-		cacheDuration), nil
+		cacheDuration,
+		logCacheErrFn,
+	), nil
 }
 
 func NoLastCommitCache() cache.Cache[CommitEntryKey, *Commit] {