ForceNew

In Terraform, sometimes a resource must be replaced when the value of an attribute changes. In SDKv2, this is accomplished via the ForceNew field. In the Framework, you implement the same behavior via a RequiresReplace plan modifier. Refer to Plan Modification - Attribute Plan Modification in the Framework documentation for details.

This page explains how to migrate this behavior from SDKv2 to the Framework.

SDKv2

In SDKv2, setting the ForceNew field on an attribute's schema.Schema triggers a replace (i.e., a destroy-create cycle) whenever the attribute's value is changed.

func resourceExample() *schema.Resource {
    return &schema.Resource{
        /* ... */
        Schema: map[string]*schema.Schema{
            "attribute_example": {
                ForceNew:    true
                /* ... */

Framework

In the Framework, you implement the same behavior by using the resource.RequiresReplace plan modifier on your attribute's schema.Attribute implementation.

func (r *ThingResource) Schema(ctx context.Context, req resource.SchemaRequest, resp *resource.SchemaResponse) {
    return schema.Schema{
        /* ... */
        Attributes: map[string]schema.Attribute{
            "attribute_example": schema.StringAttribute{
                PlanModifiers: []planmodifier.String{
                    stringplanmodifier.RequiresReplace(),
                    /* ... */

Migration Notes

Remember the following differences between SDKv2 and the Framework when completing the migration.

• In both SDKv2 and Framework, ForceNew and RequiresReplace, respectively, only trigger a replace if the attribute is not computed. In the Framework, if an attribute which is computed requires that the resource be replaced when it is changed, implement a plan modifier that triggers the replacement. Refer to RequiresReplacePlanModifier for an example, but bear in mind that each implementation requires different logic and you may need to detect whether the plan has already been modified.

Example

The following examples show how to migrate portions of the random provider.

For a complete example, clone the terraform-random-provider repository and compare the resource_password.go file in v3.3.2 with the file after the migration.

SDKv2

The following example from the resource_password.go file shows the implementation of the ForceNew field of the random_password resource's keepers attribute with SDKv2.

func resourcePassword() *schema.Resource {
    return &schema.Resource{
        Schema: map[string]*schema.Schema{
            "keepers": {
                ForceNew: true,
                /* ... */
            },
            /* ... */
        },
        /* ... */
    }
}

Framework

The following shows the same section of provider code after the migration.

This code forces the replacement of a random_password resource when the value of the keepers attribute is changed. The example does this using the PlanModifiers field within the random_password attribute's schema.

func (r *passwordResource) Schema(ctx context.Context, req resource.SchemaRequest, resp *resource.SchemaResponse) {
    resp.Schema = schema.Schema{
        Attributes: map[string]schema.Attribute{
            "keepers": schema.MapAttribute{
                PlanModifiers: []planmodifier.Map{
                    mapplanmodifier.RequiresReplace(),
                },
                /* ... */
            },
            /* ... */
        },
    }
}