WIP

examples/test/main.tf

@@ -0,0 +1,24 @@
+terraform {
+  required_providers {
+    hcp = {
+      source  = "localhost/providers/hcp"
+      version = "~>0.0.1"
+    }
+  }
+}
+
+provider "hcp" {
+  project_id = "567f02be-08ef-4609-b928-702577572393"
+}
+
+
+resource "hcp_service_principal" "example" {
+  name = "example-sp"
+}
+
+resource "hcp_project_iam_binding" "example" {
+  principal_id = hcp_service_principal.example.resource_id
+  role         = "roles/admin"
+}
+
+

internal/provider/iam/resource_service_principal.go

@@ -23,8 +23,13 @@ import (
 	"github.com/hashicorp/terraform-plugin-framework/types"
 	clients "github.com/hashicorp/terraform-provider-hcp/internal/clients"
 	"github.com/hashicorp/terraform-provider-hcp/internal/hcpvalidator"
+	"github.com/hashicorp/terraform-provider-hcp/internal/provider/modifiers"
 )
 
+var _ resource.Resource = &resourceServicePrincipal{}
+var _ resource.ResourceWithConfigure = &resourceServicePrincipal{}
+var _ resource.ResourceWithModifyPlan = &resourceServicePrincipal{}
+
 func NewServicePrincipalResource() resource.Resource {
 	return &resourceServicePrincipal{}
 }
@@ -105,6 +110,10 @@ func (r *resourceServicePrincipal) Configure(_ context.Context, req resource.Con
 	r.client = client
 }
 
+func (r *resourceServicePrincipal) ModifyPlan(ctx context.Context, req resource.ModifyPlanRequest, resp *resource.ModifyPlanResponse) {
+	modifiers.ModifyPlanForDefaultProjectChange(ctx, r.client.Config.ProjectID, req.State, req.Config, req.Plan, resp)
+}
+
 type ServicePrincipal struct {
 	ResourceID   types.String `tfsdk:"resource_id"`
 	ResourceName types.String `tfsdk:"resource_name"`

internal/provider/modifiers/project.go

@@ -41,3 +41,22 @@ func ModifyPlanForDefaultProjectChange(ctx context.Context, providerDefaultProje
 		resp.RequiresReplace.Append(projectIDPath)
 	}
 }
+
+func ModifyPlanForDefaultParentChange(ctx context.Context, providerDefaultProject string, state tfsdk.State, configAttributes, planAttributes AttrGettable, resp *resource.ModifyPlanResponse) {
+	if state.Raw.IsNull() {
+		return
+	}
+
+	projectIDPath := path.Root("project_id")
+
+	var configProject, plannedProject types.String
+	resp.Diagnostics.Append(configAttributes.GetAttribute(ctx, projectIDPath, &configProject)...)
+	resp.Diagnostics.Append(planAttributes.GetAttribute(ctx, projectIDPath, &plannedProject)...)
+
+	if configProject.IsNull() && !plannedProject.IsNull() && providerDefaultProject != plannedProject.ValueString() {
+		// There is no project configured on the resource, yet the provider project is different from
+		// the planned project value. We must conclude that the provider default project changed.
+		resp.Plan.SetAttribute(ctx, projectIDPath, types.StringValue(providerDefaultProject))
+		resp.RequiresReplace.Append(projectIDPath)
+	}
+}