feat: error type for not finding basic auth creds and export config path

errdef/errors.go

@@ -28,4 +28,5 @@ var (
 	ErrSizeExceedsLimit   = errors.New("size exceeds limit")
 	ErrUnsupported        = errors.New("unsupported")
 	ErrUnsupportedVersion = errors.New("unsupported version")
+	ErrBasicCredNotFound  = errors.New("basic credential not found")
 )

registry/remote/auth/client.go

@@ -27,6 +27,7 @@
 	"net/url"
 	"strings"
 
+	"oras.land/oras-go/v2/errdef"
 	"oras.land/oras-go/v2/registry/remote/internal/errutil"
 	"oras.land/oras-go/v2/registry/remote/retry"
 )
@@ -215,7 +216,7 @@
 			return c.fetchBasicAuth(ctx, host)
 		})
 		if err != nil {
-			return nil, fmt.Errorf("%s %q: %w", resp.Request.Method, resp.Request.URL, err)
+			return nil, err
 		}
 
 		req = originalReq.Clone(ctx)
@@ -280,7 +281,7 @@
 		return "", fmt.Errorf("failed to resolve credential: %w", err)
 	}
 	if cred == EmptyCredential {
-		return "", errors.New("credential required for basic auth")
+		return "", errdef.ErrBasicCredNotFound
 	}
 	if cred.Username == "" || cred.Password == "" {
 		return "", errors.New("missing username or password for basic auth")

registry/remote/credentials/store.go

@@ -121,7 +121,7 @@ func NewStore(configPath string, opts StoreOptions) (*DynamicStore, error) {
 //   - https://docs.docker.com/engine/reference/commandline/cli/#configuration-files
 //   - https://docs.docker.com/engine/reference/commandline/cli/#change-the-docker-directory
 func NewStoreFromDocker(opt StoreOptions) (*DynamicStore, error) {
-	configPath, err := getDockerConfigPath()
+	configPath, err := GetDockerConfigPath()
 	if err != nil {
 		return nil, err
 	}
@@ -193,8 +193,8 @@ func (ds *DynamicStore) getStore(serverAddress string) Store {
 	return fs
 }
 
-// getDockerConfigPath returns the path to the default docker config file.
-func getDockerConfigPath() (string, error) {
+// GetDockerConfigPath returns the path to the default docker config file.
+func GetDockerConfigPath() (string, error) {
 	// first try the environment variable
 	configDir := os.Getenv(dockerConfigDirEnv)
 	if configDir == "" {

registry/remote/credentials/store_test.go

@@ -878,7 +878,7 @@ func Test_getDockerConfigPath_env(t *testing.T) {
 	}
 	t.Setenv("DOCKER_CONFIG", dir)
 
-	got, err := getDockerConfigPath()
+	got, err := GetDockerConfigPath()
 	if err != nil {
 		t.Fatal("getDockerConfigPath() error =", err)
 	}
@@ -890,7 +890,7 @@ func Test_getDockerConfigPath_env(t *testing.T) {
 func Test_getDockerConfigPath_homeDir(t *testing.T) {
 	t.Setenv("DOCKER_CONFIG", "")
 
-	got, err := getDockerConfigPath()
+	got, err := GetDockerConfigPath()
 	if err != nil {
 		t.Fatal("getDockerConfigPath() error =", err)
 	}