feat: default to ADC when gcloud cred helper is configured in docker/config.json when using docker go library

Author: renzodavid9

pkg/skaffold/docker/auth.go

@@ -18,18 +18,20 @@ package docker
 
 import (
 	"context"
-	"encoding/base64"
 	"encoding/json"
 	"fmt"
 	"os"
 	"path/filepath"
 
+	"github.com/distribution/reference"
 	"github.com/docker/cli/cli/config"
 	"github.com/docker/cli/cli/config/configfile"
-	"github.com/docker/distribution/reference"
+	clitypes "github.com/docker/cli/cli/config/types"
 	types "github.com/docker/docker/api/types/registry"
 	"github.com/docker/docker/pkg/homedir"
 	"github.com/docker/docker/registry"
+	"github.com/google/go-containerregistry/pkg/authn"
+	"github.com/google/go-containerregistry/pkg/v1/google"
 
 	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/gcp"
 	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/output/log"
@@ -79,14 +81,72 @@ func (h credsHelper) GetAuthConfig(registry string) (types.AuthConfig, error) {
 		return types.AuthConfig{}, err
 	}
 
+	return h.loadCredentials(cf, registry)
+}
+
+func (h credsHelper) loadCredentials(cf *configfile.ConfigFile, registry string) (types.AuthConfig, error) {
+	if helper := cf.CredentialHelpers[registry]; helper == "gcloud" {
+		authCfg, err := h.getGoogleAuthConfig(registry)
+		if err == nil {
+			return authCfg, nil
+		}
+		log.Entry(context.TODO()).Debugf("error getting google authenticator, falling back to docker auth: %v", err)
+	}
+
+	var anonymous clitypes.AuthConfig
 	auth, err := cf.GetAuthConfig(registry)
 	if err != nil {
 		return types.AuthConfig{}, err
 	}
 
+	// From go-containerrergistry logic, the ServerAddress is not considered when determining if returned auth is anonymous.
+	anonymous.ServerAddress = auth.ServerAddress
+	if auth != anonymous {
+		return types.AuthConfig(auth), nil
+	}
+
+	if isGoogleRegistry(registry) {
+		authCfg, err := h.getGoogleAuthConfig(registry)
+		if err == nil {
+			return authCfg, nil
+		}
+	}
+
 	return types.AuthConfig(auth), nil
 }
 
+func (h credsHelper) getGoogleAuthConfig(registry string) (types.AuthConfig, error) {
+	auth, err := google.NewEnvAuthenticator()
+	if err != nil {
+		return types.AuthConfig{}, err
+	}
+
+	if auth == authn.Anonymous {
+		return types.AuthConfig{}, fmt.Errorf("error getting google authenticator")
+	}
+
+	cfg, err := auth.Authorization()
+	if err != nil {
+		return types.AuthConfig{}, err
+	}
+
+	bCfg, err := cfg.MarshalJSON()
+	if err != nil {
+		return types.AuthConfig{}, err
+	}
+
+	var authCfg types.AuthConfig
+	err = json.Unmarshal(bCfg, &authCfg)
+	if err != nil {
+		return types.AuthConfig{}, err
+	}
+
+	// The docker library does the same when we request the credentials
+	authCfg.ServerAddress = registry
+
+	return authCfg, nil
+}
+
 // GetAllAuthConfigs retrieves all the auth configs.
 // Because this can take a long time, we make sure it can be interrupted by the user.
 func (h credsHelper) GetAllAuthConfigs(ctx context.Context) (map[string]types.AuthConfig, error) {
@@ -111,22 +171,31 @@ func (h credsHelper) GetAllAuthConfigs(ctx context.Context) (map[string]types.Au
 }
 
 func (h credsHelper) doGetAllAuthConfigs() (map[string]types.AuthConfig, error) {
+	credentials := make(map[string]types.AuthConfig)
 	cf, err := loadDockerConfig()
 	if err != nil {
 		return nil, err
 	}
 
-	credentials, err := cf.GetAllCredentials()
+	defaultCreds, err := cf.GetCredentialsStore("").GetAll()
 	if err != nil {
 		return nil, err
 	}
 
-	authConfigs := make(map[string]types.AuthConfig, len(credentials))
-	for k, auth := range credentials {
-		authConfigs[k] = types.AuthConfig(auth)
+	for registry, cred := range defaultCreds {
+		credentials[registry] = types.AuthConfig(cred)
+	}
+
+	for registry := range cf.CredentialHelpers {
+		authCfg, err := h.loadCredentials(cf, registry)
+		if err != nil {
+			log.Entry(context.TODO()).Debugf("failed to get credentials for registry %v: %v", registry, err)
+			continue
+		}
+		credentials[registry] = authCfg
 	}
 
-	return authConfigs, nil
+	return credentials, nil
 }
 
 func (l *localDaemon) encodedRegistryAuth(ctx context.Context, a AuthConfigHelper, image string) (string, error) {
@@ -150,12 +219,7 @@ func (l *localDaemon) encodedRegistryAuth(ctx context.Context, a AuthConfigHelpe
 		return "", fmt.Errorf("getting auth config: %w", err)
 	}
 
-	buf, err := json.Marshal(ac)
-	if err != nil {
-		return "", err
-	}
-
-	return base64.URLEncoding.EncodeToString(buf), nil
+	return types.EncodeAuthConfig(ac)
 }
 
 func (l *localDaemon) officialRegistry(ctx context.Context) string {

pkg/skaffold/docker/auth_test.go

@@ -58,14 +58,18 @@ func TestGetAllAuthConfigs(t *testing.T) {
 		tmpDir := t.NewTempDir().
 			Write("config.json", `{"credHelpers":{"my.registry":"helper"}}`).
 			Write("docker-credential-gcloud", `#!/bin/sh
-read server
-echo "{\"Username\":\"<token>\",\"Secret\":\"TOKEN_$server\"}"`).
+	read server
+	echo "{\"Username\":\"<token>\",\"Secret\":\"TOKEN_$server\"}"`).
 			Write("docker-credential-helper", `#!/bin/sh
-read server
-echo "{\"Username\":\"<token>\",\"Secret\":\"TOKEN_$server\"}"`)
+	read server
+	echo "{\"Username\":\"<token>\",\"Secret\":\"TOKEN_$server\"}"`)
 		t.Override(&configDir, tmpDir.Root())
 		t.Setenv("PATH", tmpDir.Root())
 
+		// These env values will prevent the authenticator to use the Google authenticator, it will use docker logic instead.
+		t.Setenv("HOME", tmpDir.Root())
+		t.Setenv("GOOGLE_APPLICATION_CREDENTIALS", "")
+
 		auth, err := DefaultAuthHelper.GetAllAuthConfigs(context.Background())
 
 		t.CheckNoError(err)
@@ -89,6 +93,46 @@ echo "{\"Username\":\"<token>\",\"Secret\":\"TOKEN_$server\"}"`)
 		t.CheckError(true, err)
 		t.CheckEmpty(auth)
 	})
+
+	testutil.Run(t, "Application Default Credentials authentication", func(t *testutil.T) {
+		if runtime.GOOS == "windows" {
+			t.Skip("test doesn't work on windows")
+		}
+
+		authToken := `{"access_token":"TOKEN","expires_in": 3599}`
+		authServerURL := startTokenServer(t, authToken)
+		credentialsFile := getCredentialsFile(t, map[string]string{
+			"client_id":     "123456.apps.googleusercontent.com",
+			"client_secret": "THE-SECRET",
+			"refresh_token": "REFRESH-TOKEN",
+			"type":          "authorized_user",
+		}, authServerURL)
+
+		tmpDir := t.NewTempDir().Write("credentials.json", credentialsFile)
+		tmpDir.Write("config.json", `{"credHelpers":{"my.registry1":"helper","my.registry2":"missinghelper","gcr.io":"gcloud","us-central1-docker.pkg.dev":"otherhelper","us-east1-docker.pkg.dev":"gcloud"}}`)
+		tmpDir.Write("docker-credential-helper", `#!/bin/sh
+		read server
+		echo "{\"Username\":\"<token>\",\"Secret\":\"TOKEN_$server\"}"`)
+		tmpDir.Write("docker-credential-otherhelper", `#!/bin/sh
+		read server
+		echo "{\"Username\":\"<token>\",\"Secret\":\"TOKEN_$server\"}"`)
+
+		t.Override(&configDir, tmpDir.Root())
+		t.SetEnvs(map[string]string{
+			"PATH":                           tmpDir.Root(),
+			"HOME":                           tmpDir.Root(), // This is to prevent the go-containerregistry library from using ADCs that are already present on the computer.
+			"GOOGLE_APPLICATION_CREDENTIALS": tmpDir.Path("credentials.json"),
+		})
+
+		auth, err := DefaultAuthHelper.GetAllAuthConfigs(context.Background())
+		t.CheckNoError(err)
+		t.CheckDeepEqual(map[string]registry.AuthConfig{
+			"gcr.io":                     {Username: "_token", Password: "TOKEN", Auth: "X3Rva2VuOlRPS0VO", ServerAddress: "gcr.io"},
+			"us-east1-docker.pkg.dev":    {Username: "_token", Password: "TOKEN", Auth: "X3Rva2VuOlRPS0VO", ServerAddress: "us-east1-docker.pkg.dev"},
+			"us-central1-docker.pkg.dev": {IdentityToken: "TOKEN_us-central1-docker.pkg.dev", ServerAddress: "us-central1-docker.pkg.dev"},
+			"my.registry1":               {IdentityToken: "TOKEN_my.registry1", ServerAddress: "my.registry1"},
+		}, auth)
+	})
 }
 
 func TestGetEncodedRegistryAuth(t *testing.T) {