page_title | description |
---|---|
Attribute Custom Validators: Migrating from SDKv2 to the Framework |
Validations check for required syntax, types, and acceptable values. Migrate custom attribute validation functions from SDKv2 to attribute validators in the Framework. |
You can write custom validations that give users feedback about required syntax, types, and acceptable values in your provider. The Framework has a collection of predefined validators. Refer to Predefined Validators to learn how to use them.
This page explains how to migrate attribute validation functions from SDKv2 to attribute validators in the Framework.
In SDKv2, arbitrary validation logic can be applied to individual attributes by using ValidateFunc
and/or
ValidateDiagFunc
.
The following example shows the implementation of a validation that ensures that an integer attribute has a value greater than one.
func resourceExample() *schema.Resource {
return &schema.Resource{
/* ... */
Schema: map[string]*schema.Schema{
"attribute_example": {
ValidateDiagFunc: validation.ToDiagFunc(validation.IntAtLeast(1)),
/* ... */
In the Framework, you implement either type of validation by setting the Validators
field on the schema.Attribute
implementation.
The following example shows how to implement a validation that ensures that an integer attribute has a value greater than one.
func (r *ThingResource) Schema(ctx context.Context, req resource.SchemaRequest, resp *resource.SchemaResponse) {
resp.Schema = schema.Schema{
/* ... */
Attributes: map[string]schema.Attribute{
"attribute_example": schema.Int64Attribute{
Validators: []validator.Int64{
int64validator.AtLeast(1),
/* ... */
Remember the following details when migrating from SDKv2 to the Framework.
- In SDKv2,
ValidateDiagFunc
is a field onschema.Schema
that you can use to define custom validation functions. In the Framework,Validators
is a field on eachschema.Attribute
implementation that can be used for custom validations. - Use predefined validators when there is a validator that meets your requirements.
The following example shows the implementation of the ValidateDiagFunc
field for
the exampleResource
's example_attribute
attribute to validate that it's value is at least 1 (greater than zero).
func exampleResource() *schema.Resource {
return &schema.Resource{
Schema: map[string]*schema.Schema{
"example_attribute": {
ValidateDiagFunc: validation.ToDiagFunc(validation.IntAtLeast(1)),
},
},
}
}
The following shows the same section of provider code after the migration.
This code validates that the exampleResource
's example_attribute
attribute is greater than zero by using a custom AtLeast
validator.
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{
Required: true,
Validators: []validator.Int64{
int64validator.AtLeast(1),
},
},
},
}
}
This example code illustrates how you can implement your own validators.
var _ validator.Int64 = atLeastValidator{}
// atLeastValidator validates that an integer Attribute's value is at least a certain value.
type atLeastValidator struct {
min int64
}
// Description describes the validation in plain text formatting.
func (v atLeastValidator) Description(_ context.Context) string {
return fmt.Sprintf("value must be at least %d", validator.min)
}
// MarkdownDescription describes the validation in Markdown formatting.
func (v atLeastValidator) MarkdownDescription(ctx context.Context) string {
return validator.Description(ctx)
}
// Validate performs the validation.
func (v atLeastValidator) ValidateInt64(ctx context.Context, request validator.Int64Request, response *validator.Int64Response) {
if req.ConfigValue.Int64Value() < validator.min {
response.Diagnostics.Append(validatordiag.InvalidAttributeValueDiagnostic(
request.Path,
v.Description(ctx),
fmt.Sprintf("%d", req.ConfigValue.Int64Value()),
))
}
}
// AtLeast returns an AttributeValidator which ensures that any configured
// attribute value:
//
// - Is a number, which can be represented by a 64-bit integer.
// - Is exclusively greater than the given minimum.
//
// Null (unconfigured) and unknown (known after apply) values are skipped.
func AtLeast(min int64) validator.Int64 {
return atLeastValidator{
min: min,
}
}