feat(redis): \authorize ha mode

Author: jremy42

docs/resources/redis_cluster.md

@@ -100,8 +100,12 @@ you cannot downgrade a Redis™ cluster.
 
 - `cluster_size` - (Optional) The number of nodes in the Redis™ cluster.
 
-~> **Important:** You cannot set `cluster_size` to 2, you either have to choose Standalone mode (1 node) or cluster mode
-which is minimum 3 (1 main node + 2 secondary nodes)
+~> **Important:**
+- Cluster_size = 1 for Standalone mode (single node).
+
+- Cluster_size = 2 for High Availability (HA) mode, with 1 main node and 1 standby node.
+
+- Cluster_size >= 3 for Cluster mode, which requires a minimum of 1 main node and 2 secondary nodes.
 
 ~> **Important:** If you are using the cluster mode (>=3 nodes), you can set a bigger `cluster_size` than you initially
 did, it will migrate the Redis™ cluster but keep in mind that you cannot downgrade a Redis™ cluster, so setting a smaller

internal/services/redis/cluster.go

@@ -223,12 +223,22 @@ func ResourceCluster() *schema.Resource {
 func customizeDiffMigrateClusterSize() schema.CustomizeDiffFunc {
 	return func(_ context.Context, diff *schema.ResourceDiff, _ interface{}) error {
 		oldSize, newSize := diff.GetChange("cluster_size")
-		if newSize == 2 {
-			return errors.New("cluster_size can be either 1 (standalone) ou >3 (cluster mode), not 2")
+
+		newSizeInt := newSize.(int)
+		oldSizeInt := oldSize.(int)
+
+		if oldSizeInt == 1 && newSizeInt == 3 {
+			return nil
 		}
-		if oldSize == 1 && newSize != 1 || newSize.(int) < oldSize.(int) {
+
+		if newSizeInt == 2 || newSizeInt <= 0 {
+			return errors.New("invalid cluster_size: must be 1 (standalone), 3 (cluster mode), or higher in certain configurations")
+		}
+
+		if newSizeInt < oldSizeInt || (oldSizeInt != 1 && newSizeInt == 1) {
 			return diff.ForceNew("cluster_size")
 		}
+
 		return nil
 	}
 }

internal/services/redis/cluster_test.go

@@ -785,6 +785,40 @@ func TestAccCluster_NoCertificate(t *testing.T) {
 	})
 }
 
+func TestAccCluster_MigrateToHAMode(t *testing.T) {
+	tt := acctest.NewTestTools(t)
+	defer tt.Cleanup()
+	latestRedisVersion := getLatestVersion(tt)
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:          func() { acctest.PreCheck(t) },
+		ProviderFactories: tt.ProviderFactories,
+		CheckDestroy:      isClusterDestroyed(tt),
+		Steps: []resource.TestStep{
+			{
+				Config: fmt.Sprintf(`
+				resource "scaleway_redis_cluster" "main" {
+				  name         = "test_redis_migrate_to_ha"
+				  version      = "%s"
+				  node_type    = "RED1-XS"
+				  user_name    = "initial_user"
+				  password     = "thiZ_is_v&ry_s3cret"
+				  cluster_size = 2
+				  tls_enabled  = "true"
+				  zone         = "fr-par-1"
+				}
+				`, latestRedisVersion),
+				Check: resource.ComposeTestCheckFunc(
+					isClusterPresent(tt, "scaleway_redis_cluster.main"),
+					resource.TestCheckResourceAttr("scaleway_redis_cluster.main", "cluster_size", "2"),
+					resource.TestCheckResourceAttr("scaleway_redis_cluster.main", "name", "test_redis_migrate_to_ha"),
+					resource.TestCheckResourceAttr("scaleway_redis_cluster.main", "zone", "fr-par-1"),
+				),
+			},
+		},
+	})
+}
+
 func isClusterDestroyed(tt *acctest.TestTools) resource.TestCheckFunc {
 	return func(state *terraform.State) error {
 		for _, rs := range state.RootModule().Resources {