[CC-30768] don't allow node_count for serverless cluster

Previously it was possible to pass in the node_count value for
serverless region because the type is shared with dedicated clusters.
This ended up causing a state inconsistency however becase node_count is
coerced to 0 by the api which conflicts with a value added in the
config. To solve this, we simply validate that node_count is not used
unless cluster plan is Advanced.

CHANGELOG.md

@@ -5,7 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [1.11.0] - 2024-12-05
+### Fixed
+
+- Validate that `node_count` is not passed in with serverless cluster regions.
+  Also, clear up in the documentation that this is not allowed.
 
 ### Added
 

docs/resources/cluster.md

@@ -113,7 +113,7 @@ Required:
 
 Optional:
 
-- `node_count` (Number) Number of nodes in the region. Will always be 0 for serverless clusters.
+- `node_count` (Number) Number of nodes in the region. Valid for Advanced clusters only.
 - `primary` (Boolean) Set to true to mark this region as the primary for a serverless cluster. Exactly one region must be primary. Dedicated clusters expect to have no primary region.
 
 Read-Only:

docs/resources/cmek.md

@@ -81,7 +81,7 @@ Required:
 
 Optional:
 
-- `node_count` (Number) Number of nodes in the region. Will always be 0 for serverless clusters.
+- `node_count` (Number) Number of nodes in the region. Valid for Advanced clusters only.
 - `primary` (Boolean) Set to true to mark this region as the primary for a serverless cluster. Exactly one region must be primary. Dedicated clusters expect to have no primary region.
 
 Read-Only:

internal/provider/cluster_resource.go

@@ -90,7 +90,7 @@ var regionSchema = schema.NestedAttributeObject{
 			PlanModifiers: []planmodifier.Int64{
 				int64planmodifier.UseStateForUnknown(),
 			},
-			Description: "Number of nodes in the region. Will always be 0 for serverless clusters.",
+			Description: "Number of nodes in the region. Valid for Advanced clusters only.",
 		},
 		"primary": schema.BoolAttribute{
 			Optional:    true,
@@ -376,6 +376,38 @@ func (r *clusterResource) ConfigValidators(_ context.Context) []resource.ConfigV
 	}
 }
 
+func (r *clusterResource) ValidateConfig(ctx context.Context, req resource.ValidateConfigRequest, resp *resource.ValidateConfigResponse) {
+
+	// ValidateConfig seems to be called multiple times, once before any values
+	// are known.  When all values are unknown we can't convert to our cluster
+	// model because we use some custom fields such as Regions.  Wait until
+	// things are defined before converting the config to our model.
+	var regions types.List
+	resp.Diagnostics.Append(req.Config.GetAttribute(ctx, path.Root("regions"), &regions)...)
+	if regions.IsUnknown() {
+		return
+	}
+
+	var cluster CockroachCluster
+	resp.Diagnostics.Append(req.Config.Get(ctx, &cluster)...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	plan, err := derivePlanType(&cluster)
+	if err != nil {
+		resp.Diagnostics.AddError("Invalid Configuration", err.Error())
+		return
+	}
+	if plan != client.PLANTYPE_ADVANCED {
+		for i, region := range cluster.Regions {
+			if IsKnown(region.NodeCount) {
+				resp.Diagnostics.AddAttributeError(path.Root("regions").AtListIndex(i), "Invalid Attribute", "node_count is supported for ADVANCED clusters only.")
+			}
+		}
+	}
+}
+
 func derivePlanType(cluster *CockroachCluster) (client.PlanType, error) {
 	var planType client.PlanType
 	if IsKnown(cluster.Plan) {

internal/provider/cluster_resource_test.go

@@ -826,6 +826,30 @@ func TestIntegrationServerlessClusterResource(t *testing.T) {
 		finalCluster      client.Cluster
 		ignoreImportPaths []string
 	}{
+		{
+			name: "STANDARD clusters must not have a node_count",
+			createStep: func() resource.TestStep {
+				return resource.TestStep{
+					Config: fmt.Sprintf(`
+						resource "cockroach_cluster" "test" {
+							name           = "%s"
+							cloud_provider = "GCP"
+							serverless = {}
+							regions = [
+								{
+									name = "us-central1"
+								},
+								{
+									name = "us-central1"
+									node_count = 1
+								},
+							]
+						}
+					`, clusterName),
+					ExpectError: regexp.MustCompile("node_count is supported for ADVANCED clusters only"),
+				}
+			},
+		},
 		{
 			name: "single-region serverless BASIC cluster converted to unlimited resources",
 			createStep: func() resource.TestStep {