[RFC-0010] Add provider audience to cache key and decouple packages

auth/gcp/gke_metadata_test.go

@@ -17,51 +17,25 @@ limitations under the License.
 package gcp_test
 
 import (
-	"context"
-	"errors"
 	"fmt"
-	"net"
 	"net/http"
+	"net/http/httptest"
+	"strings"
 	"testing"
-	"time"
-
-	. "github.com/onsi/gomega"
 )
 
 func startGKEMetadataServer(t *testing.T) {
 	t.Helper()
-	g := NewWithT(t)
-
-	lis, err := net.Listen("tcp", ":0")
-	g.Expect(err).NotTo(HaveOccurred())
-
-	gkeMetadataServer := &http.Server{
-		Addr: lis.Addr().String(),
-		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			switch r.URL.Path {
-			case "/computeMetadata/v1/project/project-id":
-				fmt.Fprintf(w, "%s", "project-id")
-			case "/computeMetadata/v1/instance/attributes/cluster-location":
-				fmt.Fprintf(w, "%s", "cluster-location")
-			case "/computeMetadata/v1/instance/attributes/cluster-name":
-				fmt.Fprintf(w, "%s", "cluster-name")
-			}
-		}),
-	}
-
-	go func() {
-		err := gkeMetadataServer.Serve(lis)
-		if err != nil && !errors.Is(err, http.ErrServerClosed) {
-			g.Expect(err).NotTo(HaveOccurred())
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/computeMetadata/v1/project/project-id":
+			fmt.Fprintf(w, "%s", "project-id")
+		case "/computeMetadata/v1/instance/attributes/cluster-location":
+			fmt.Fprintf(w, "%s", "cluster-location")
+		case "/computeMetadata/v1/instance/attributes/cluster-name":
+			fmt.Fprintf(w, "%s", "cluster-name")
 		}
-	}()
-
-	t.Cleanup(func() {
-		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-		defer cancel()
-		err := gkeMetadataServer.Shutdown(ctx)
-		g.Expect(err).NotTo(HaveOccurred())
-	})
-
-	t.Setenv("GCE_METADATA_HOST", lis.Addr().String())
+	}))
+	t.Cleanup(srv.Close)
+	t.Setenv("GCE_METADATA_HOST", strings.TrimPrefix(srv.URL, "http://"))
 }

auth/gcp/options.go

@@ -40,11 +40,11 @@ func getServiceAccountEmail(serviceAccount corev1.ServiceAccount) (string, error
 	return email, nil
 }
 
-const workloadIdentityProviderPattern = `^https://iam\.googleapis\.com/projects/\d{1,30}/locations/global/workloadIdentityPools/[^/]{1,100}/providers/[^/]{1,100}$`
+const workloadIdentityProviderPattern = `^projects/\d{1,30}/locations/global/workloadIdentityPools/[^/]{1,100}/providers/[^/]{1,100}$`
 
 var workloadIdentityProviderRegex = regexp.MustCompile(workloadIdentityProviderPattern)
 
-func getWorkloadIdentityProvider(serviceAccount corev1.ServiceAccount) (string, error) {
+func getWorkloadIdentityProviderAudience(serviceAccount corev1.ServiceAccount) (string, error) {
 	const key = "gcp.auth.fluxcd.io/workload-identity-provider"
 	wip := serviceAccount.Annotations[key]
 	if wip == "" {
@@ -54,5 +54,5 @@ func getWorkloadIdentityProvider(serviceAccount corev1.ServiceAccount) (string,
 		return "", fmt.Errorf("invalid %s annotation: '%s'. must match %s",
 			key, wip, workloadIdentityProviderPattern)
 	}
-	return wip, nil
+	return fmt.Sprintf("https://iam.googleapis.com/%s", wip), nil
 }

auth/gcp/provider.go

@@ -70,7 +70,7 @@ func (p Provider) NewControllerToken(ctx context.Context, opts ...auth.Option) (
 func (Provider) GetAudience(ctx context.Context, serviceAccount corev1.ServiceAccount) (string, error) {
 	// Check if a workload identity provider is specified in the service account.
 	// If so, the current cluster is not GKE and the audience is the provider itself.
-	audience, err := getWorkloadIdentityProvider(serviceAccount)
+	audience, err := getWorkloadIdentityProviderAudience(serviceAccount)
 	if err != nil {
 		return "", err
 	}
@@ -100,7 +100,7 @@ func (p Provider) NewTokenForServiceAccount(ctx context.Context, oidcToken strin
 
 	// Check if a workload identity provider is specified in the service account.
 	// If so, the current cluster is not GKE and the audience is the provider itself.
-	audience, err := getWorkloadIdentityProvider(serviceAccount)
+	audience, err := getWorkloadIdentityProviderAudience(serviceAccount)
 	if err != nil {
 		return nil, err
 	}

auth/gcp/provider_test.go

@@ -109,7 +109,7 @@ func TestProvider_NewTokenForServiceAccount(t *testing.T) {
 				UniverseDomain:       "googleapis.com",
 			},
 			annotations: map[string]string{
-				"gcp.auth.fluxcd.io/workload-identity-provider": "https://iam.googleapis.com/projects/1234567890/locations/global/workloadIdentityPools/test-pool/providers/test-provider",
+				"gcp.auth.fluxcd.io/workload-identity-provider": "projects/1234567890/locations/global/workloadIdentityPools/test-pool/providers/test-provider",
 			},
 		},
 		{
@@ -128,7 +128,7 @@ func TestProvider_NewTokenForServiceAccount(t *testing.T) {
 			},
 			annotations: map[string]string{
 				"iam.gke.io/gcp-service-account":                "[email protected]",
-				"gcp.auth.fluxcd.io/workload-identity-provider": "https://iam.googleapis.com/projects/1234567890/locations/global/workloadIdentityPools/test-pool/providers/test-provider",
+				"gcp.auth.fluxcd.io/workload-identity-provider": "projects/1234567890/locations/global/workloadIdentityPools/test-pool/providers/test-provider",
 			},
 		},
 		{
@@ -143,7 +143,7 @@ func TestProvider_NewTokenForServiceAccount(t *testing.T) {
 			annotations: map[string]string{
 				"gcp.auth.fluxcd.io/workload-identity-provider": "foobar",
 			},
-			err: `invalid gcp.auth.fluxcd.io/workload-identity-provider annotation: 'foobar'. must match ^https://iam\.googleapis\.com/projects/\d{1,30}/locations/global/workloadIdentityPools/[^/]{1,100}/providers/[^/]{1,100}$`,
+			err: `invalid gcp.auth.fluxcd.io/workload-identity-provider annotation: 'foobar'. must match ^projects/\d{1,30}/locations/global/workloadIdentityPools/[^/]{1,100}/providers/[^/]{1,100}$`,
 		},
 	} {
 		t.Run(tt.name, func(t *testing.T) {
@@ -195,7 +195,7 @@ func TestProvider_GetAudience(t *testing.T) {
 		{
 			name: "federation",
 			annotations: map[string]string{
-				"gcp.auth.fluxcd.io/workload-identity-provider": "https://iam.googleapis.com/projects/1234567890/locations/global/workloadIdentityPools/test-pool/providers/test-provider",
+				"gcp.auth.fluxcd.io/workload-identity-provider": "projects/1234567890/locations/global/workloadIdentityPools/test-pool/providers/test-provider",
 			},
 			expected: "https://iam.googleapis.com/projects/1234567890/locations/global/workloadIdentityPools/test-pool/providers/test-provider",
 		},

auth/get_token.go

@@ -45,6 +45,7 @@ func GetToken(ctx context.Context, provider Provider, opts ...Option) (Token, er
 	}
 
 	// Update access token fetcher for a service account if specified.
+	var providerAudience string
 	var providerIdentity string
 	var serviceAccountP *corev1.ServiceAccount
 	if o.ServiceAccount != nil {
@@ -63,7 +64,7 @@ func GetToken(ctx context.Context, provider Provider, opts ...Option) (Token, er
 
 		// Get provider audience.
 		var err error
-		providerAudience, err := provider.GetAudience(ctx, serviceAccount)
+		providerAudience, err = provider.GetAudience(ctx, serviceAccount)
 		if err != nil {
 			return nil, fmt.Errorf("failed to get provider audience: %w", err)
 		}
@@ -131,7 +132,8 @@ func GetToken(ctx context.Context, provider Provider, opts ...Option) (Token, er
 	}
 
 	// Build cache key.
-	cacheKey := buildCacheKey(provider, providerIdentity, artifactRepositoryCacheKey, serviceAccountP, opts...)
+	cacheKey := buildCacheKey(provider, providerAudience, providerIdentity,
+		artifactRepositoryCacheKey, serviceAccountP, opts...)
 
 	// Get involved object details.
 	kind := o.InvolvedObject.Kind
@@ -163,7 +165,7 @@ func newServiceAccountToken(ctx context.Context, client client.Client,
 	return tokenReq.Status.Token, nil
 }
 
-func buildCacheKey(provider Provider, providerIdentity, artifactRepositoryKey string,
+func buildCacheKey(provider Provider, providerAudience, providerIdentity, artifactRepositoryKey string,
 	serviceAccount *corev1.ServiceAccount, opts ...Option) string {
 
 	var o Options
@@ -174,6 +176,7 @@ func buildCacheKey(provider Provider, providerIdentity, artifactRepositoryKey st
 	keyParts = append(keyParts, fmt.Sprintf("provider=%s", provider.GetName()))
 
 	if serviceAccount != nil {
+		keyParts = append(keyParts, fmt.Sprintf("providerAudience=%s", providerAudience))
 		keyParts = append(keyParts, fmt.Sprintf("providerIdentity=%s", providerIdentity))
 		keyParts = append(keyParts, fmt.Sprintf("serviceAccountName=%s", serviceAccount.Name))
 		keyParts = append(keyParts, fmt.Sprintf("serviceAccountNamespace=%s", serviceAccount.Namespace))

auth/get_token_test.go

@@ -309,6 +309,7 @@ func TestGetToken(t *testing.T) {
 			name: "all the options are taken into account in the cache key",
 			provider: &mockProvider{
 				returnName:              "mock-provider",
+				returnAudience:          "mock-audience",
 				returnIdentity:          "mock-identity",
 				returnRegistryInput:     "artifact-cache-key",
 				paramServiceAccount:     *defaultServiceAccount,
@@ -325,7 +326,7 @@ func TestGetToken(t *testing.T) {
 					tokenCache, err := cache.NewTokenCache(1)
 					g.Expect(err).NotTo(HaveOccurred())
 
-					const key = "da48da328aa46181e677d76c835b7ca32b5fbf64da01577463d42a2720708ecb"
+					const key = "3e8e270134e99fda1a01d7dca77f29448eb4c7f6cc026137b85a1bcd96b276fa"
 					token := &mockToken{token: "cached-token"}
 					cachedToken, ok, err := tokenCache.GetOrSet(ctx, key, func(ctx context.Context) (cache.Token, error) {
 						return token, nil

auth/go.mod

@@ -2,10 +2,7 @@ module github.com/fluxcd/pkg/auth
 
 go 1.24.0
 
-replace (
-	github.com/fluxcd/pkg/cache => ../cache
-	github.com/fluxcd/pkg/ssh => ../ssh
-)
+replace github.com/fluxcd/pkg/cache => ../cache
 
 require (
 	cloud.google.com/go/compute/metadata v0.6.0

auth/utils/doc.go

@@ -14,9 +14,11 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-// authutils contains utility functions that import both the core
-// auth package and the provider packages i.e. functions that
-// cannot be placed in the core package because they would cause
-// a cyclic dependency (the provider packages also import the
-// core package).
+// authutils contains small utility functions without much logic
+// wrapping the major APIs of the core auth package for ease of use
+// in the controllers. These functions also import the provider
+// packages to wrap switch-case choice of provider implementations.
+// Because of that, these functions cannot be placed in the core
+// package as they would cause a cyclic dependency given that the
+// provider packages also import the core package.
 package authutils

auth/utils/git.go

@@ -0,0 +1,51 @@
+/*
+Copyright 2025 The Flux authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package authutils
+
+import (
+	"context"
+	"errors"
+
+	"github.com/fluxcd/pkg/auth"
+	"github.com/fluxcd/pkg/auth/azure"
+)
+
+// GitCredentials contains authentication data needed in order to access a Git
+// repository.
+type GitCredentials struct {
+	BearerToken string
+	Username    string
+	Password    string
+}
+
+// GetGitCredentials looks up by the implemented providers that support Git
+// and returns the credentials for the provider.
+func GetGitCredentials(ctx context.Context, providerName string, opts ...auth.Option) (*GitCredentials, error) {
+	switch providerName {
+	case azure.ProviderName:
+		opts = append(opts, auth.WithScopes(azure.ScopeDevOps))
+		token, err := auth.GetToken(ctx, azure.Provider{}, opts...)
+		if err != nil {
+			return nil, err
+		}
+		return &GitCredentials{
+			BearerToken: token.(*azure.Token).Token,
+		}, nil
+	default:
+		return nil, errors.New("unsupported provider")
+	}
+}