feat: support redis as external cache (#29)

* feat: support redis as external state cache

* feat: support redis as external state cache

* feat: support redis as external state cache

go.mod

@@ -21,6 +21,7 @@ require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.2.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
 	github.com/go-jose/go-jose/v3 v3.0.3 // indirect
 	github.com/go-jose/go-jose/v4 v4.0.1 // indirect
 	github.com/golang-jwt/jwt/v5 v5.2.0 // indirect
@@ -29,6 +30,7 @@ require (
 	github.com/prometheus/client_model v0.6.0 // indirect
 	github.com/prometheus/common v0.52.3 // indirect
 	github.com/prometheus/procfs v0.12.0 // indirect
+	github.com/redis/go-redis/v9 v9.5.3 // indirect
 	golang.org/x/crypto v0.22.0 // indirect
 	golang.org/x/sys v0.19.0 // indirect
 	google.golang.org/protobuf v1.33.0 // indirect

go.sum

@@ -16,6 +16,8 @@ github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ3
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
+github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
 github.com/go-jose/go-jose/v3 v3.0.3 h1:fFKWeig/irsp7XD2zBxvnmA/XaRWp5V3CBsZXJF7G7k=
 github.com/go-jose/go-jose/v3 v3.0.3/go.mod h1:5b+7YgP7ZICgJDBdfjZaIt+H/9L9T/YQrVfLAMboGkQ=
 github.com/go-jose/go-jose/v4 v4.0.1 h1:QVEPDE3OluqXBQZDcnNvQrInro2h0e4eqNbnZSWqS6U=
@@ -41,6 +43,8 @@ github.com/prometheus/common v0.52.3 h1:5f8uj6ZwHSscOGNdIQg6OiZv/ybiK2CO2q2drVZA
 github.com/prometheus/common v0.52.3/go.mod h1:BrxBKv3FWBIGXw89Mg1AeBq7FSyRzXWI3l3e7W3RN5U=
 github.com/prometheus/procfs v0.12.0 h1:jluTpSng7V9hY0O2R9DzzJHYb2xULk9VTR1V1R/k6Bo=
 github.com/prometheus/procfs v0.12.0/go.mod h1:pcuDEFsWDnvcgNzo4EEweacyhjeA9Zk3cnaOZAZEfOo=
+github.com/redis/go-redis/v9 v9.5.3 h1:fOAp1/uJG+ZtcITgZOfYFmTKPE7n4Vclj1wZFgRciUU=
+github.com/redis/go-redis/v9 v9.5.3/go.mod h1:hdY0cQFCN4fnSYT6TkisLufl/4W5UIXyv0b/CLO2V2M=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

internal/cmd/run.go

@@ -10,6 +10,7 @@ import (
 	"github.com/clambin/traefik-simple-auth/pkg/state"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"github.com/redis/go-redis/v9"
 	"io"
 	"log/slog"
 	"net/http"
@@ -80,7 +81,18 @@ func makeStateStore(cfg configuration.CacheConfiguration) state.States[string] {
 		backend = state.NewLocalCache[string]()
 	case "memcached":
 		backend = state.MemcachedCache[string]{
-			Client: memcache.New(cfg.MemcachedConfiguration.Addr),
+			Namespace: "github.com/clambin/traefik-simple-auth",
+			Client:    memcache.New(cfg.MemcachedConfiguration.Addr),
+		}
+	case "redis":
+		backend = state.RedisCache[string]{
+			Namespace: "github.com/clambin/traefik-simple-auth",
+			Client: redis.NewClient(&redis.Options{
+				Addr:     cfg.RedisConfiguration.Addr,
+				DB:       cfg.RedisConfiguration.Database,
+				Username: cfg.RedisConfiguration.Username,
+				Password: cfg.RedisConfiguration.Password,
+			}),
 		}
 	default:
 		panic("unknown backend: " + cfg.Backend)

internal/server/configuration/configuration.go

@@ -27,6 +27,10 @@ var (
 	secret             = flag.String("secret", "", "Secret to use for authentication (base64 encoded)")
 	cacheBackend       = flag.String("cache", "memory", "The backend to use for caching")
 	cacheMemcachedAddr = flag.String("cache-memcached-addr", "", "memcached address to use (only used when cache backend is memcached)")
+	cacheRedisAddr     = flag.String("cache-redis-addr", "", "redis address to use (only used when cache backend is redis)")
+	cacheRedisDatabase = flag.Int("cache-redis-database", 0, "redis database to use (only used when cache backend is redis)")
+	cacheRedisUsername = flag.String("cache-redis-username", "", "Redis username (only used when cache backend is redis)")
+	cacheRedisPassword = flag.String("cache-redis-password", "", "Redis password (only used when cache backend is redis)")
 )
 
 type Configuration struct {
@@ -81,6 +85,12 @@ func GetConfiguration() (Configuration, error) {
 			MemcachedConfiguration: MemcachedConfiguration{
 				Addr: *cacheMemcachedAddr,
 			},
+			RedisConfiguration: RedisConfiguration{
+				Addr:     *cacheRedisAddr,
+				Database: *cacheRedisDatabase,
+				Username: *cacheRedisUsername,
+				Password: *cacheRedisPassword,
+			},
 		},
 	}
 	var err error

pkg/state/state.go

@@ -12,6 +12,7 @@ import (
 	"errors"
 	"github.com/bradfitz/gomemcache/memcache"
 	"github.com/clambin/go-common/cache"
+	"github.com/redis/go-redis/v9"
 	"time"
 )
 
@@ -80,7 +81,8 @@ func (l LocalCache[T]) len(_ context.Context) (int, error) {
 }
 
 type MemcachedCache[T any] struct {
-	Client MemcachedClient
+	Namespace string
+	Client    MemcachedClient
 }
 
 type MemcachedClient interface {
@@ -93,7 +95,7 @@ func (m MemcachedCache[T]) add(_ context.Context, key string, value T, ttl time.
 	val, err := encode[T](value)
 	if err == nil {
 		err = m.Client.Set(&memcache.Item{
-			Key:        key,
+			Key:        m.Namespace + "|" + key,
 			Value:      val,
 			Expiration: int32(ttl.Seconds()),
 		})
@@ -102,6 +104,7 @@ func (m MemcachedCache[T]) add(_ context.Context, key string, value T, ttl time.
 }
 
 func (m MemcachedCache[T]) get(_ context.Context, key string) (T, error) {
+	key = m.Namespace + "|" + key
 	item, err := m.Client.Get(key)
 	if err == nil {
 		err = m.Client.Delete(key)
@@ -140,3 +143,39 @@ func decode[T any](value []byte) (v T, err error) {
 	}
 	return v, err
 }
+
+var _ Backend[string] = RedisCache[string]{}
+
+type RedisCache[T any] struct {
+	Namespace string
+	Client    RedisClient
+}
+
+type RedisClient interface {
+	Set(context.Context, string, any, time.Duration) *redis.StatusCmd
+	GetDel(context.Context, string) *redis.StringCmd
+}
+
+func (r RedisCache[T]) add(ctx context.Context, key string, value T, ttl time.Duration) error {
+	val, err := encode[T](value)
+	if err == nil {
+		err = r.Client.Set(ctx, r.Namespace+"|"+key, val, ttl).Err()
+	}
+	return err
+}
+
+func (r RedisCache[T]) get(ctx context.Context, key string) (T, error) {
+	val, err := r.Client.GetDel(ctx, r.Namespace+"|"+key).Result()
+	if err != nil {
+		if errors.Is(err, redis.Nil) {
+			err = ErrNotFound
+		}
+		var value T
+		return value, err
+	}
+	return decode[T]([]byte(val))
+}
+
+func (r RedisCache[T]) len(_ context.Context) (int, error) {
+	return 0, nil
+}

pkg/state/state_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"github.com/bradfitz/gomemcache/memcache"
 	"github.com/clambin/go-common/cache"
+	"github.com/redis/go-redis/v9"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"testing"
@@ -25,7 +26,15 @@ func TestStates(t *testing.T) {
 		{
 			name: "memcachedCache",
 			backend: MemcachedCache[string]{
-				Client: &fakeMemcachedClient{c: LocalCache[string]{values: cache.New[string, string](0, 0)}},
+				Namespace: "github.com/clambin/traefik-simple-auth",
+				Client:    &fakeMemcachedClient{c: LocalCache[string]{values: cache.New[string, string](0, 0)}},
+			},
+		},
+		{
+			name: "redisCache",
+			backend: RedisCache[string]{
+				Namespace: "github.com/clambin/traefik-simple-auth",
+				Client:    &fakeRedisClient{c: LocalCache[string]{values: cache.New[string, string](0, 0)}},
 			},
 		},
 	}
@@ -101,3 +110,27 @@ func (f *fakeMemcachedClient) Delete(key string) error {
 	f.c.values.Remove(key)
 	return nil
 }
+
+var _ RedisClient = fakeRedisClient{}
+
+type fakeRedisClient struct {
+	c LocalCache[string]
+}
+
+func (f fakeRedisClient) Set(ctx context.Context, key string, value any, ttl time.Duration) *redis.StatusCmd {
+	err := f.c.add(ctx, key, string(value.([]byte)), ttl)
+	cmd := redis.NewStatusCmd(ctx)
+	cmd.SetErr(err)
+	return cmd
+}
+
+func (f fakeRedisClient) GetDel(ctx context.Context, key string) *redis.StringCmd {
+	val, err := f.c.get(ctx, key)
+	if errors.Is(err, ErrNotFound) {
+		err = redis.Nil
+	}
+	cmd := redis.NewStringCmd(ctx)
+	cmd.SetErr(err)
+	cmd.SetVal(val)
+	return cmd
+}