validate that cluster's project id stays constant

Author: maciaszczykm

internal/resource/cluster.go

@@ -110,12 +110,18 @@ func (r *clusterResource) Read(ctx context.Context, req resource.ReadRequest, re
 }
 
 func (r *clusterResource) Update(ctx context.Context, req resource.UpdateRequest, resp *resource.UpdateResponse) {
-	var data cluster
+	var data, state cluster
 	resp.Diagnostics.Append(req.Plan.Get(ctx, &data)...)
+	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
 	if resp.Diagnostics.HasError() {
 		return
 	}
 
+	if !data.ProjectId.Equal(state.ProjectId) {
+		resp.Diagnostics.AddError("Invalid Configuration", fmt.Sprintf("Unable to update cluster, project ID must not be modified"))
+		return
+	}
+
 	_, err := r.client.UpdateCluster(ctx, data.Id.ValueString(), data.UpdateAttributes(ctx, resp.Diagnostics))
 	if err != nil {
 		resp.Diagnostics.AddError("Client Error", fmt.Sprintf("Unable to update cluster, got error: %s", err))