Add pinniped_supported_identity_provider_types to the IDP discovery e…

…ndpoint

apis/supervisor/idpdiscovery/v1alpha1/types_supervisor_idp_discovery.go.tmpl

@@ -1,4 +1,4 @@
-// Copyright 2021-2022 the Pinniped contributors. All Rights Reserved.
+// Copyright 2021-2024 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 package v1alpha1
@@ -54,7 +54,8 @@ type OIDCDiscoveryResponseIDPEndpoint struct {
 
 // IDPDiscoveryResponse is the response of a FederationDomain's identity provider discovery endpoint.
 type IDPDiscoveryResponse struct {
-	PinnipedIDPs []PinnipedIDP `json:"pinniped_identity_providers"`
+	PinnipedIDPs              []PinnipedIDP              `json:"pinniped_identity_providers"`
+	PinnipedSupportedIDPTypes []PinnipedSupportedIDPType `json:"pinniped_supported_identity_provider_types"`
 }
 
 // PinnipedIDP describes a single identity provider as included in the response of a FederationDomain's
@@ -64,3 +65,8 @@ type PinnipedIDP struct {
 	Type  IDPType   `json:"type"`
 	Flows []IDPFlow `json:"flows,omitempty"`
 }
+
+// PinnipedSupportedIDPType describes a single identity provider type.
+type PinnipedSupportedIDPType struct {
+	Type IDPType `json:"type"`
+}

internal/federationdomain/endpoints/idpdiscovery/idp_discovery_handler.go

@@ -37,15 +37,23 @@ func NewHandler(upstreamIDPs federationdomainproviders.FederationDomainIdentityP
 }
 
 func responseAsJSON(upstreamIDPs federationdomainproviders.FederationDomainIdentityProvidersListerI) ([]byte, error) {
-	r := v1alpha1.IDPDiscoveryResponse{PinnipedIDPs: []v1alpha1.PinnipedIDP{}}
+	r := v1alpha1.IDPDiscoveryResponse{
+		PinnipedSupportedIDPTypes: []v1alpha1.PinnipedSupportedIDPType{
+			{Type: v1alpha1.IDPTypeActiveDirectory},
+			{Type: v1alpha1.IDPTypeLDAP},
+			{Type: v1alpha1.IDPTypeOIDC},
+		},
+	}
 
+	upstreams := upstreamIDPs.GetIdentityProviders()
+	r.PinnipedIDPs = make([]v1alpha1.PinnipedIDP, len(upstreams))
 	// The cache of IDPs could change at any time, so always recalculate the list.
-	for _, federationDomainIdentityProvider := range upstreamIDPs.GetIdentityProviders() {
-		r.PinnipedIDPs = append(r.PinnipedIDPs, v1alpha1.PinnipedIDP{
+	for i, federationDomainIdentityProvider := range upstreams {
+		r.PinnipedIDPs[i] = v1alpha1.PinnipedIDP{
 			Name:  federationDomainIdentityProvider.GetDisplayName(),
 			Type:  federationDomainIdentityProvider.GetIDPDiscoveryType(),
 			Flows: federationDomainIdentityProvider.GetIDPDiscoveryFlows(),
-		})
+		}
 	}
 
 	// Nobody like an API that changes the results unnecessarily. :)