Add validators for UUID attributes

The API often doesn't return useful error messages. In cases where users
might mistakenly use names of resources rather than their corresponding
ids, this can lead to confusion. Improve usability by adding some
validation.

Author: aidy

internal/provider/cloudprovider_gcp_resource.go

@@ -8,12 +8,14 @@ import (
 	"fmt"
 
 	"terraform-provider-tlspc/internal/tlspc"
+	"terraform-provider-tlspc/internal/validators"
 
 	"github.com/hashicorp/terraform-plugin-framework/path"
 	"github.com/hashicorp/terraform-plugin-framework/resource"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema/stringplanmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/schema/validator"
 	"github.com/hashicorp/terraform-plugin-framework/types"
 )
 
@@ -60,6 +62,9 @@ func (r *cloudProviderGCPResource) Schema(_ context.Context, _ resource.SchemaRe
 			"team": schema.StringAttribute{
 				Required:            true,
 				MarkdownDescription: "The ID of the owning Team",
+				Validators: []validator.String{
+					validators.Uuid(),
+				},
 			},
 			"service_account_email": schema.StringAttribute{
 				Required:            true,

internal/provider/registry_account_resource.go

@@ -8,12 +8,14 @@ import (
 	"fmt"
 
 	"terraform-provider-tlspc/internal/tlspc"
+	"terraform-provider-tlspc/internal/validators"
 
 	"github.com/hashicorp/terraform-plugin-framework/path"
 	"github.com/hashicorp/terraform-plugin-framework/resource"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema/stringplanmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/schema/validator"
 	"github.com/hashicorp/terraform-plugin-framework/types"
 )
 
@@ -52,6 +54,9 @@ func (r *registryAccountResource) Schema(_ context.Context, _ resource.SchemaReq
 			"owner": schema.StringAttribute{
 				Required:            true,
 				MarkdownDescription: "ID of the team that owns this service account",
+				Validators: []validator.String{
+					validators.Uuid(),
+				},
 			},
 			"scopes": schema.SetAttribute{
 				Required:    true,

internal/provider/service_account_resource.go

@@ -8,12 +8,14 @@ import (
 	"fmt"
 
 	"terraform-provider-tlspc/internal/tlspc"
+	"terraform-provider-tlspc/internal/validators"
 
 	"github.com/hashicorp/terraform-plugin-framework/path"
 	"github.com/hashicorp/terraform-plugin-framework/resource"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema/stringplanmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/schema/validator"
 	"github.com/hashicorp/terraform-plugin-framework/types"
 )
 
@@ -52,6 +54,9 @@ func (r *serviceAccountResource) Schema(_ context.Context, _ resource.SchemaRequ
 			"owner": schema.StringAttribute{
 				Required:            true,
 				MarkdownDescription: "ID of the team that owns this service account",
+				Validators: []validator.String{
+					validators.Uuid(),
+				},
 			},
 			"scopes": schema.SetAttribute{
 				Required:    true,

internal/validators/uuid.go

@@ -0,0 +1,45 @@
+package validators
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/google/uuid"
+	"github.com/hashicorp/terraform-plugin-framework/schema/validator"
+)
+
+func Uuid() uuidValidator {
+	return uuidValidator{}
+}
+
+type uuidValidator struct {
+}
+
+// Description returns a plain text description of the validator's behavior, suitable for a practitioner to understand its impact.
+func (v uuidValidator) Description(ctx context.Context) string {
+	return "string must be a uuid"
+}
+
+// MarkdownDescription returns a markdown formatted description of the validator's behavior, suitable for a practitioner to understand its impact.
+func (v uuidValidator) MarkdownDescription(ctx context.Context) string {
+	return "string must be a uuid"
+}
+
+// Validate runs the main validation logic of the validator, reading configuration data out of `req` and updating `resp` with diagnostics.
+func (v uuidValidator) ValidateString(ctx context.Context, req validator.StringRequest, resp *validator.StringResponse) {
+	// If the value is unknown or null, there is nothing to validate.
+	if req.ConfigValue.IsUnknown() || req.ConfigValue.IsNull() {
+		return
+	}
+
+	if err := uuid.Validate(req.ConfigValue.ValueString()); err != nil {
+
+		resp.Diagnostics.AddAttributeError(
+			req.Path,
+			"Invalid uuid",
+			fmt.Sprintf("String must be a uuid: %s", err),
+		)
+
+		return
+	}
+}