Default Values
Default values support is only available in the Framework for resources. Handle default values for data source attributes within the data source Read
method and default values for provider attributes within the provider Configure
method.
Default values set a value for an attribute when the Terraform configuration does not provide one. In SDKv2 and the
Framework default values are set via the Default
field on an attribute's schema.
Refer to
Default
in the Framework documentation for details.
This page explains how to migrate attribute defaults in SDKv2 to the Framework.
SDKv2
In SDKv2, default values are defined for a primitive attribute type (i.e., TypeBool
, TypeFloat
, TypeInt
,
TypeString
) by the Default
field on the attribute's schema. Alternatively, the DefaultFunc
function is used to
compute a default value for an attribute.
The following code shows a basic implementation of a default value for a primitive attribute type in SDKv2.
func resourceExample() *schema.Resource { return &schema.Resource{ /* ... */ Schema: map[string]*schema.Schema{ "attribute_example": { Default: 2048, /* ... */ }, /* ... */
Framework
In the Framework, you set default values with the Default
field on your attribute's definition.
import ( "context" "github.com/hashicorp/terraform-plugin-framework/resource" "github.com/hashicorp/terraform-plugin-framework/resource/schema" "github.com/hashicorp/terraform-plugin-framework/resource/schema/booldefault") func (r *resourceExample) Schema(ctx context.Context, req resource.SchemaRequest, resp *resource.SchemaResponse) { resp.Schema = schema.Schema{ /* ... */ Attributes: map[string]schema.Attribute{ "attribute_example": schema.BoolAttribute{ Default: booldefault.StaticBool(true), /* ... */
Migration Notes
Remember the following differences between SDKv2 and the Framework when completing the migration.
- In SDKv2, default values are set with the
Default
orDefaultFunc
fields on an attribute'sschema.Schema
struct. In the Framework, you must assign set theDefault
field on an attribute to set a default value.
Example
SDKv2
The following example shows the implementation of the Default
field for the
example_attribute
attribute on the exampleResource
resource with SDKv2.
func exampleResource() *schema.Resource { return &schema.Resource{ Schema: map[string]*schema.Schema{ "example_attribute": { Default: 2048, /* ... */ }, /* ... */
Framework
The following shows the same section of code after the migration.
This code implements the PlanModifiers
field for the example_attribute
attribute with the Framework.
func (r *exampleResource) Schema(ctx context.Context, req resource.SchemaRequest, resp *resource.SchemaResponse) { resp.Schema = schema.Schema{ Attributes: map[string]schema.Attribute{ "example_attribute": schema.Int64Attribute{ Default: int64default.StaticInt64(2048) /* ... */ }, /* ... */ }, }, nil}