Merge branch 'pr-3707'

* pr-3707:
  config updates for ElastiCache test
  Removing the instance_type check in the ElastiCache cluster creation. We now allow the error to bubble up to the userr when the wrong instance type is used. The limitation for t2 instance types now allowing snapshotting is also now documented
  Making the changes to the snapshotting for Elasticache Redis as per @catsby's findings
  Added an extra test for the Elasticache Cluster to show that updates work. Also added some debugging to show that the API returns the Elasticache retention period info
  When I was setting the update parameters for the Snapshotting, I didn't update the copy/pasted params
  Adding the ability to specify a snapshot window and retention limit for Redis ElastiCache clusters

builtin/providers/aws/resource_aws_elasticache_cluster.go

@@ -138,6 +138,24 @@ func resourceAwsElasticacheCluster() *schema.Resource {
 				},
 			},
 
+			"snapshot_window": &schema.Schema{
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+
+			"snapshot_retention_limit": &schema.Schema{
+				Type:     schema.TypeInt,
+				Optional: true,
+				ValidateFunc: func(v interface{}, k string) (ws []string, es []error) {
+					value := v.(int)
+					if value > 35 {
+						es = append(es, fmt.Errorf(
+							"snapshot retention limit cannot be more than 35 days"))
+					}
+					return
+				},
+			},
+
 			"tags": tagsSchema(),
 
 			// apply_immediately is used to determine when the update modifications
@@ -187,6 +205,14 @@ func resourceAwsElasticacheClusterCreate(d *schema.ResourceData, meta interface{
 		req.CacheParameterGroupName = aws.String(v.(string))
 	}
 
+	if v, ok := d.GetOk("snapshot_retention_limit"); ok {
+		req.SnapshotRetentionLimit = aws.Int64(int64(v.(int)))
+	}
+
+	if v, ok := d.GetOk("snapshot_window"); ok {
+		req.SnapshotWindow = aws.String(v.(string))
+	}
+
 	if v, ok := d.GetOk("maintenance_window"); ok {
 		req.PreferredMaintenanceWindow = aws.String(v.(string))
 	}
@@ -267,6 +293,8 @@ func resourceAwsElasticacheClusterRead(d *schema.ResourceData, meta interface{})
 		d.Set("security_group_ids", c.SecurityGroups)
 		d.Set("parameter_group_name", c.CacheParameterGroup)
 		d.Set("maintenance_window", c.PreferredMaintenanceWindow)
+		d.Set("snapshot_window", c.SnapshotWindow)
+		d.Set("snapshot_retention_limit", c.SnapshotRetentionLimit)
 		if c.NotificationConfiguration != nil {
 			if *c.NotificationConfiguration.TopicStatus == "active" {
 				d.Set("notification_topic_arn", c.NotificationConfiguration.TopicArn)
@@ -350,6 +378,16 @@ func resourceAwsElasticacheClusterUpdate(d *schema.ResourceData, meta interface{
 		requestUpdate = true
 	}
 
+	if d.HasChange("snapshot_window") {
+		req.SnapshotWindow = aws.String(d.Get("snapshot_window").(string))
+		requestUpdate = true
+	}
+
+	if d.HasChange("snapshot_retention_limit") {
+		req.SnapshotRetentionLimit = aws.Int64(int64(d.Get("snapshot_retention_limit").(int)))
+		requestUpdate = true
+	}
+
 	if d.HasChange("num_cache_nodes") {
 		req.NumCacheNodes = aws.Int64(int64(d.Get("num_cache_nodes").(int)))
 		requestUpdate = true

builtin/providers/aws/resource_aws_elasticache_cluster_test.go

@@ -33,6 +33,45 @@ func TestAccAWSElasticacheCluster_basic(t *testing.T) {
 	})
 }
 
+func TestAccAWSElasticacheCluster_snapshotsWithUpdates(t *testing.T) {
+	var ec elasticache.CacheCluster
+
+	ri := genRandInt()
+	preConfig := fmt.Sprintf(testAccAWSElasticacheClusterConfig_snapshots, ri, ri, ri)
+	postConfig := fmt.Sprintf(testAccAWSElasticacheClusterConfig_snapshotsUpdated, ri, ri, ri)
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckAWSElasticacheClusterDestroy,
+		Steps: []resource.TestStep{
+			resource.TestStep{
+				Config: preConfig,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckAWSElasticacheSecurityGroupExists("aws_elasticache_security_group.bar"),
+					testAccCheckAWSElasticacheClusterExists("aws_elasticache_cluster.bar", &ec),
+					resource.TestCheckResourceAttr(
+						"aws_elasticache_cluster.bar", "snapshot_window", "05:00-09:00"),
+					resource.TestCheckResourceAttr(
+						"aws_elasticache_cluster.bar", "snapshot_retention_limit", "3"),
+				),
+			},
+
+			resource.TestStep{
+				Config: postConfig,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckAWSElasticacheSecurityGroupExists("aws_elasticache_security_group.bar"),
+					testAccCheckAWSElasticacheClusterExists("aws_elasticache_cluster.bar", &ec),
+					resource.TestCheckResourceAttr(
+						"aws_elasticache_cluster.bar", "snapshot_window", "07:00-09:00"),
+					resource.TestCheckResourceAttr(
+						"aws_elasticache_cluster.bar", "snapshot_retention_limit", "7"),
+				),
+			},
+		},
+	})
+}
+
 func TestAccAWSElasticacheCluster_vpc(t *testing.T) {
 	var csg elasticache.CacheSubnetGroup
 	var ec elasticache.CacheCluster
@@ -152,6 +191,75 @@ resource "aws_elasticache_cluster" "bar" {
 }
 `, genRandInt(), genRandInt(), genRandInt())
 
+var testAccAWSElasticacheClusterConfig_snapshots = `
+provider "aws" {
+	region = "us-east-1"
+}
+resource "aws_security_group" "bar" {
+    name = "tf-test-security-group-%03d"
+    description = "tf-test-security-group-descr"
+    ingress {
+        from_port = -1
+        to_port = -1
+        protocol = "icmp"
+        cidr_blocks = ["0.0.0.0/0"]
+    }
+}
+
+resource "aws_elasticache_security_group" "bar" {
+    name = "tf-test-security-group-%03d"
+    description = "tf-test-security-group-descr"
+    security_group_names = ["${aws_security_group.bar.name}"]
+}
+
+resource "aws_elasticache_cluster" "bar" {
+    cluster_id = "tf-test-%03d"
+    engine = "redis"
+    node_type = "cache.m1.small"
+    num_cache_nodes = 1
+    port = 6379
+  	parameter_group_name = "default.redis2.8"
+    security_group_names = ["${aws_elasticache_security_group.bar.name}"]
+    snapshot_window = "05:00-09:00"
+    snapshot_retention_limit = 3
+}
+`
+
+var testAccAWSElasticacheClusterConfig_snapshotsUpdated = `
+provider "aws" {
+	region = "us-east-1"
+}
+resource "aws_security_group" "bar" {
+    name = "tf-test-security-group-%03d"
+    description = "tf-test-security-group-descr"
+    ingress {
+        from_port = -1
+        to_port = -1
+        protocol = "icmp"
+        cidr_blocks = ["0.0.0.0/0"]
+    }
+}
+
+resource "aws_elasticache_security_group" "bar" {
+    name = "tf-test-security-group-%03d"
+    description = "tf-test-security-group-descr"
+    security_group_names = ["${aws_security_group.bar.name}"]
+}
+
+resource "aws_elasticache_cluster" "bar" {
+    cluster_id = "tf-test-%03d"
+    engine = "redis"
+    node_type = "cache.m1.small"
+    num_cache_nodes = 1
+    port = 6379
+  	parameter_group_name = "default.redis2.8"
+    security_group_names = ["${aws_elasticache_security_group.bar.name}"]
+    snapshot_window = "07:00-09:00"
+    snapshot_retention_limit = 7
+    apply_immediately = true
+}
+`
+
 var testAccAWSElasticacheClusterInVPCConfig = fmt.Sprintf(`
 resource "aws_vpc" "foo" {
     cidr_block = "192.168.0.0/16"

website/source/docs/providers/aws/r/elasticache_cluster.html.markdown

@@ -73,12 +73,22 @@ names to associate with this cache cluster
 Amazon Resource Name (ARN) of a Redis RDB snapshot file stored in Amazon S3. 
 Example: `arn:aws:s3:::my_bucket/snapshot1.rdb`
 
+* `snapshot_window` - (Optional) The daily time range (in UTC) during which ElastiCache will 
+begin taking a daily snapshot of your cache cluster. Can only be used for the Redis engine. Example: 05:00-09:00
+
+* `snapshow_retention_limit` - (Optional) The number of days for which ElastiCache will 
+retain automatic cache cluster snapshots before deleting them. For example, if you set 
+SnapshotRetentionLimit to 5, then a snapshot that was taken today will be retained for 5 days 
+before being deleted. If the value of SnapshotRetentionLimit is set to zero (0), backups are turned off. 
+Can only be used for the Redis engine.
+
 * `notification_topic_arn` – (Optional) An Amazon Resource Name (ARN) of an 
 SNS topic to send ElastiCache notifications to. Example: 
 `arn:aws:sns:us-east-1:012345678999:my_sns_topic`
 
 * `tags` - (Optional) A mapping of tags to assign to the resource.
 
+~> **NOTE:** Snapshotting functionality is not compatible with t2 instance types.
 
 ## Attributes Reference