From 1975db0b9489befb2f2cd56e7b227b2612ed1a4f Mon Sep 17 00:00:00 2001
From: Andrew Starr-Bochicchio <andrewsomething@users.noreply.github.com>
Date: Fri, 21 Apr 2023 10:36:37 -0400
Subject: [PATCH] databases: Add support for resizing replicas. (#977)

---
 .../database/resource_database_replica.go     | 33 +++++++++-
 .../resource_database_replica_test.go         | 61 +++++++++++++++++++
 docs/resources/database_replica.md            |  2 +-
 3 files changed, 94 insertions(+), 2 deletions(-)

diff --git a/digitalocean/database/resource_database_replica.go b/digitalocean/database/resource_database_replica.go
index 290260057..88e249e3c 100644
--- a/digitalocean/database/resource_database_replica.go
+++ b/digitalocean/database/resource_database_replica.go
@@ -22,6 +22,7 @@ func ResourceDigitalOceanDatabaseReplica() *schema.Resource {
 	return &schema.Resource{
 		CreateContext: resourceDigitalOceanDatabaseReplicaCreate,
 		ReadContext:   resourceDigitalOceanDatabaseReplicaRead,
+		UpdateContext: resourceDigitalOceanDatabaseReplicaUpdate,
 		DeleteContext: resourceDigitalOceanDatabaseReplicaDelete,
 		Importer: &schema.ResourceImporter{
 			State: resourceDigitalOceanDatabaseReplicaImport,
@@ -58,7 +59,6 @@ func ResourceDigitalOceanDatabaseReplica() *schema.Resource {
 			"size": {
 				Type:     schema.TypeString,
 				Optional: true,
-				ForceNew: true,
 			},
 
 			"private_network_uuid": {
@@ -217,6 +217,37 @@ func resourceDigitalOceanDatabaseReplicaRead(ctx context.Context, d *schema.Reso
 	return nil
 }
 
+func resourceDigitalOceanDatabaseReplicaUpdate(ctx context.Context, d *schema.ResourceData, meta interface{}) diag.Diagnostics {
+	client := meta.(*config.CombinedConfig).GodoClient()
+	clusterID := d.Get("cluster_id").(string)
+	replicaID := d.Get("uuid").(string)
+	replicaName := d.Get("name").(string)
+
+	if d.HasChanges("size") {
+		opts := &godo.DatabaseResizeRequest{
+			SizeSlug: d.Get("size").(string),
+			NumNodes: 1, // Read-only replicas only support a single node configuration.
+		}
+
+		resp, err := client.Databases.Resize(context.Background(), replicaID, opts)
+		if err != nil {
+			if resp != nil && resp.StatusCode == 404 {
+				d.SetId("")
+				return nil
+			}
+
+			return diag.Errorf("Error resizing database replica: %s", err)
+		}
+
+		_, err = waitForDatabaseReplica(client, clusterID, "online", replicaName)
+		if err != nil {
+			return diag.Errorf("Error resizing database replica: %s", err)
+		}
+	}
+
+	return resourceDigitalOceanDatabaseReplicaRead(ctx, d, meta)
+}
+
 func resourceDigitalOceanDatabaseReplicaImport(d *schema.ResourceData, meta interface{}) ([]*schema.ResourceData, error) {
 	if strings.Contains(d.Id(), ",") {
 		s := strings.Split(d.Id(), ",")
diff --git a/digitalocean/database/resource_database_replica_test.go b/digitalocean/database/resource_database_replica_test.go
index 5e2dff28a..7cff31160 100644
--- a/digitalocean/database/resource_database_replica_test.go
+++ b/digitalocean/database/resource_database_replica_test.go
@@ -105,6 +105,58 @@ func TestAccDigitalOceanDatabaseReplica_WithVPC(t *testing.T) {
 	})
 }
 
+func TestAccDigitalOceanDatabaseReplica_Resize(t *testing.T) {
+	var databaseReplica godo.DatabaseReplica
+	var database godo.Database
+
+	databaseName := acceptance.RandomTestName()
+	databaseReplicaName := acceptance.RandomTestName()
+
+	databaseConfig := fmt.Sprintf(testAccCheckDigitalOceanDatabaseClusterConfigBasic, databaseName)
+	replicaConfig := fmt.Sprintf(testAccCheckDigitalOceanDatabaseReplicaConfigBasic, databaseReplicaName)
+	resizedConfig := fmt.Sprintf(testAccCheckDigitalOceanDatabaseReplicaConfigResized, databaseReplicaName)
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:          func() { acceptance.TestAccPreCheck(t) },
+		ProviderFactories: acceptance.TestAccProviderFactories,
+		CheckDestroy:      testAccCheckDigitalOceanDatabaseReplicaDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: databaseConfig,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckDigitalOceanDatabaseClusterExists("digitalocean_database_cluster.foobar", &database),
+				),
+			},
+			{
+				Config: databaseConfig + replicaConfig,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckDigitalOceanDatabaseReplicaExists("digitalocean_database_replica.read-01", &databaseReplica),
+					testAccCheckDigitalOceanDatabaseReplicaAttributes(&databaseReplica, databaseReplicaName),
+					resource.TestCheckResourceAttr(
+						"digitalocean_database_replica.read-01", "size", "db-s-1vcpu-2gb"),
+					resource.TestCheckResourceAttr(
+						"digitalocean_database_replica.read-01", "name", databaseReplicaName),
+					resource.TestCheckResourceAttrSet(
+						"digitalocean_database_replica.read-01", "uuid"),
+				),
+			},
+			{
+				Config: databaseConfig + resizedConfig,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckDigitalOceanDatabaseReplicaExists("digitalocean_database_replica.read-01", &databaseReplica),
+					testAccCheckDigitalOceanDatabaseReplicaAttributes(&databaseReplica, databaseReplicaName),
+					resource.TestCheckResourceAttr(
+						"digitalocean_database_replica.read-01", "size", "db-s-2vcpu-4gb"),
+					resource.TestCheckResourceAttr(
+						"digitalocean_database_replica.read-01", "name", databaseReplicaName),
+					resource.TestCheckResourceAttrSet(
+						"digitalocean_database_replica.read-01", "uuid"),
+				),
+			},
+		},
+	})
+}
+
 func testAccCheckDigitalOceanDatabaseReplicaDestroy(s *terraform.State) error {
 	client := acceptance.TestAccProvider.Meta().(*config.CombinedConfig).GodoClient()
 
@@ -182,6 +234,15 @@ resource "digitalocean_database_replica" "read-01" {
   tags       = ["staging"]
 }`
 
+const testAccCheckDigitalOceanDatabaseReplicaConfigResized = `
+resource "digitalocean_database_replica" "read-01" {
+  cluster_id = digitalocean_database_cluster.foobar.id
+  name       = "%s"
+  region     = "nyc3"
+  size       = "db-s-2vcpu-4gb"
+  tags       = ["staging"]
+}`
+
 const testAccCheckDigitalOceanDatabaseReplicaConfigWithVPC = `
 
 
diff --git a/docs/resources/database_replica.md b/docs/resources/database_replica.md
index 0b8bf8e00..94c30a7f7 100644
--- a/docs/resources/database_replica.md
+++ b/docs/resources/database_replica.md
@@ -47,7 +47,7 @@ The following arguments are supported:
 
 * `cluster_id` - (Required) The ID of the original source database cluster.
 * `name` - (Required) The name for the database replica.
-* `size` - (Required) Database Droplet size associated with the replica (ex. `db-s-1vcpu-1gb`).
+* `size` - (Required) Database Droplet size associated with the replica (ex. `db-s-1vcpu-1gb`). Note that when resizing an existing replica, its size can only be increased. Decreasing its size is not supported.
 * `region` - (Required) DigitalOcean region where the replica will reside.
 * `tags` - (Optional) A list of tag names to be applied to the database replica.
 * `private_network_uuid` - (Optional) The ID of the VPC where the database replica will be located.