From f2f4c72aa6607bd3ad2788c048306d939ff40797 Mon Sep 17 00:00:00 2001
From: Nitesh Agarwal <niteshagarwal1.618@gmail.com>
Date: Thu, 17 Feb 2022 19:54:15 +0530
Subject: [PATCH] Add redis cluster client as a session store.

---
 .gitignore                            |  3 ++-
 server/sessionstore/redis_store.go    |  4 +---
 server/sessionstore/session.go        | 34 +++++++++++++++++++++++++++
 server/sessionstore/session_client.go | 18 ++++++++++++++
 4 files changed, 55 insertions(+), 4 deletions(-)
 create mode 100644 server/sessionstore/session_client.go

diff --git a/.gitignore b/.gitignore
index bab8c91..d979474 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,4 +10,5 @@ build
 data.db
 .DS_Store
 .env.local
-*.tar.gz
\ No newline at end of file
+*.tar.gz
+.vscode/
\ No newline at end of file
diff --git a/server/sessionstore/redis_store.go b/server/sessionstore/redis_store.go
index 658b5e4..4531e0f 100644
--- a/server/sessionstore/redis_store.go
+++ b/server/sessionstore/redis_store.go
@@ -4,13 +4,11 @@ import (
 	"context"
 	"fmt"
 	"log"
-
-	"github.com/go-redis/redis/v8"
 )
 
 type RedisStore struct {
 	ctx   context.Context
-	store *redis.Client
+	store RedisSessionClient
 }
 
 // AddUserSession adds the user session to redis
diff --git a/server/sessionstore/session.go b/server/sessionstore/session.go
index aeaad1d..523dee6 100644
--- a/server/sessionstore/session.go
+++ b/server/sessionstore/session.go
@@ -3,6 +3,7 @@ package sessionstore
 import (
 	"context"
 	"log"
+	"strings"
 
 	"github.com/authorizerdev/authorizer/server/constants"
 	"github.com/authorizerdev/authorizer/server/envstore"
@@ -121,6 +122,23 @@ func RemoveSocialLoginState(key string) {
 func InitSession() {
 	if envstore.EnvInMemoryStoreObj.GetStringStoreEnvVariable(constants.EnvKeyRedisURL) != "" {
 		log.Println("using redis store to save sessions")
+		if isCluster(envstore.EnvInMemoryStoreObj.GetStringStoreEnvVariable(constants.EnvKeyRedisURL)) {
+			clusterOpt, err := getClusterOptions(envstore.EnvInMemoryStoreObj.GetStringStoreEnvVariable(constants.EnvKeyRedisURL))
+			if err != nil {
+				log.Fatalln("Error parsing redis url:", err)
+			}
+			rdb := redis.NewClusterClient(clusterOpt)
+			ctx := context.Background()
+			_, err = rdb.Ping(ctx).Result()
+			if err != nil {
+				log.Fatalln("Error connecting to redis cluster server", err)
+			}
+			SessionStoreObj.RedisMemoryStoreObj = &RedisStore{
+				ctx:   ctx,
+				store: rdb,
+			}
+			return
+		}
 		opt, err := redis.ParseURL(envstore.EnvInMemoryStoreObj.GetStringStoreEnvVariable(constants.EnvKeyRedisURL))
 		if err != nil {
 			log.Fatalln("Error parsing redis url:", err)
@@ -144,3 +162,19 @@ func InitSession() {
 		}
 	}
 }
+
+func isCluster(url string) bool {
+	return len(strings.Split(url, ",")) > 1
+}
+
+func getClusterOptions(url string) (*redis.ClusterOptions, error) {
+	hostPortsList := strings.Split(url, ",")
+	opt, err := redis.ParseURL(hostPortsList[0])
+	if err != nil {
+		return nil, err
+	}
+	urls := []string{opt.Addr}
+	urlList := hostPortsList[1:]
+	urls = append(urls, urlList...)
+	return &redis.ClusterOptions{Addrs: urls}, nil
+}
diff --git a/server/sessionstore/session_client.go b/server/sessionstore/session_client.go
new file mode 100644
index 0000000..e73cd74
--- /dev/null
+++ b/server/sessionstore/session_client.go
@@ -0,0 +1,18 @@
+package sessionstore
+
+import (
+	"context"
+	"time"
+
+	"github.com/go-redis/redis/v8"
+)
+
+type RedisSessionClient interface {
+	HMSet(ctx context.Context, key string, values ...interface{}) *redis.BoolCmd
+	Del(ctx context.Context, keys ...string) *redis.IntCmd
+	HDel(ctx context.Context, key string, fields ...string) *redis.IntCmd
+	HMGet(ctx context.Context, key string, fields ...string) *redis.SliceCmd
+	HGetAll(ctx context.Context, key string) *redis.StringStringMapCmd
+	Set(ctx context.Context, key string, value interface{}, expiration time.Duration) *redis.StatusCmd
+	Get(ctx context.Context, key string) *redis.StringCmd
+}