fix: Instance image diff during Instance import

linode/instancedisk/framework_resource.go

@@ -207,7 +207,21 @@ func (r *Resource) Read(
 		return
 	}
 
+	// Only populate Image if state.Image is null and the parent instance has an image set
+	if state.Image.IsNull() {
+		instance, err := client.GetInstance(ctx, linodeID)
+		if err != nil {
+			tflog.Debug(ctx, "Failed to fetch parent instance for disk image fallback", map[string]any{
+				"linode_id": linodeID,
+				"error":     err.Error(),
+			})
+		} else if instance.Image != "" {
+			state.Image = types.StringValue(instance.Image)
+		}
+	}
+
 	state.FlattenDisk(disk, false)
+
 	resp.Diagnostics.Append(resp.State.Set(ctx, &state)...)
 }
 

linode/instancedisk/framework_resource_schema.go

@@ -85,6 +85,7 @@ var frameworkResourceSchema = schema.Schema{
 			Optional:    true,
 			PlanModifiers: []planmodifier.String{
 				stringplanmodifier.RequiresReplace(),
+				stringplanmodifier.UseStateForUnknown(),
 			},
 		},
 		"root_pass": schema.StringAttribute{