feat: add package client, the Program type and its related operations (…

…#68)

Resolves #67

Signed-off-by: Xiaoxuan Wang <[email protected]>

go.mod

@@ -2,14 +2,10 @@ module github.com/oras-project/oras-credentials-go
 
 go 1.19
 
-require (
-	github.com/docker/docker-credential-helpers v0.7.0
-	oras.land/oras-go/v2 v2.2.0
-)
+require oras.land/oras-go/v2 v2.2.0
 
 require (
 	github.com/opencontainers/go-digest v1.0.0 // indirect
 	github.com/opencontainers/image-spec v1.1.0-rc.3 // indirect
 	golang.org/x/sync v0.2.0 // indirect
-	golang.org/x/sys v0.8.0 // indirect
 )

go.sum

@@ -1,12 +1,8 @@
-github.com/docker/docker-credential-helpers v0.7.0 h1:xtCHsjxogADNZcdv1pKUHXryefjlVRqWqIhk/uXJp0A=
-github.com/docker/docker-credential-helpers v0.7.0/go.mod h1:rETQfLdHNT3foU5kuNkFR1R1V12OJRRO5lzt2D1b5X0=
 github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
 github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
 github.com/opencontainers/image-spec v1.1.0-rc.3 h1:GT9Xon8YrLxz6N7sErbN81V8J4lOQKGUZQmI3ioviqU=
 github.com/opencontainers/image-spec v1.1.0-rc.3/go.mod h1:X4pATf0uXsnn3g5aiGIsVnJBR4mxhKzfwmvK/B2NTm8=
 golang.org/x/sync v0.2.0 h1:PUR+T4wwASmuSTYdKjYHI5TD22Wy5ogLU5qZCOLxBrI=
 golang.org/x/sync v0.2.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=
-golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 oras.land/oras-go/v2 v2.2.0 h1:E1fqITD56Eg5neZbxBtAdZVgDHD6wBabJo6xESTcQyo=
 oras.land/oras-go/v2 v2.2.0/go.mod h1:pXjn0+KfarspMHHNR3A56j3tgvr+mxArHuI8qVn59v8=

internal/executer/executer.go

@@ -0,0 +1,61 @@
+/*
+Copyright The ORAS 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 executer is an abstraction for the docker credential helper protocol
+// binaries. It is used by nativeStore to interact with installed binaries.
+package executer
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"io"
+	"os"
+	"os/exec"
+)
+
+// Executer is an interface that simulates an executable binary.
+type Executer interface {
+	Execute(ctx context.Context, input io.Reader, action string) ([]byte, error)
+}
+
+// executable implements the Executer interface.
+type executable struct {
+	name string
+}
+
+// New returns a new Executer instance.
+func New(name string) Executer {
+	return &executable{
+		name: name,
+	}
+}
+
+// Execute operates on an executable binary and supports context.
+func (c *executable) Execute(ctx context.Context, input io.Reader, action string) ([]byte, error) {
+	cmd := exec.CommandContext(ctx, c.name, action)
+	cmd.Stdin = input
+	cmd.Stderr = os.Stderr
+	output, err := cmd.Output()
+	if err != nil {
+		if _, ok := err.(*exec.ExitError); ok {
+			if errMessage := string(bytes.TrimSpace(output)); errMessage != "" {
+				err = errors.New(errMessage)
+			}
+		}
+		return nil, err
+	}
+	return output, nil
+}

native_store.go

@@ -16,11 +16,13 @@ limitations under the License.
 package credentials
 
 import (
+	"bytes"
 	"context"
+	"encoding/json"
 	"os/exec"
+	"strings"
 
-	"github.com/docker/docker-credential-helpers/client"
-	"github.com/docker/docker-credential-helpers/credentials"
+	"github.com/oras-project/oras-credentials-go/internal/executer"
 	"oras.land/oras-go/v2/registry/remote/auth"
 )
 
@@ -29,10 +31,20 @@ const (
 	emptyUsername           = "<token>"
 )
 
+// dockerCredentials mimics how docker credential helper binaries store
+// credential information.
+// Reference:
+//   - https://docs.docker.com/engine/reference/commandline/login/#credential-helper-protocol
+type dockerCredentials struct {
+	ServerURL string `json:"ServerURL"`
+	Username  string `json:"Username"`
+	Secret    string `json:"Secret"`
+}
+
 // nativeStore implements a credentials store using native keychain to keep
 // credentials secure.
 type nativeStore struct {
-	programFunc client.ProgramFunc
+	exec executer.Executer
 }
 
 // NewNativeStore creates a new native store that uses a remote helper program to
@@ -46,22 +58,22 @@ type nativeStore struct {
 //   - https://docs.docker.com/engine/reference/commandline/login#credentials-store
 func NewNativeStore(helperSuffix string) Store {
 	return &nativeStore{
-		programFunc: client.NewShellProgramFunc(remoteCredentialsPrefix + helperSuffix),
+		exec: executer.New(remoteCredentialsPrefix + helperSuffix),
 	}
 }
 
 // Get retrieves credentials from the store for the given server.
-func (ns *nativeStore) Get(_ context.Context, serverAddress string) (auth.Credential, error) {
+func (ns *nativeStore) Get(ctx context.Context, serverAddress string) (auth.Credential, error) {
 	var cred auth.Credential
-	dockerCred, err := client.Get(ns.programFunc, serverAddress)
+	out, err := ns.exec.Execute(ctx, strings.NewReader(serverAddress), "get")
 	if err != nil {
-		if credentials.IsErrCredentialsNotFound(err) {
-			// do not return an error if the credentials are not in the keychain.
-			return auth.EmptyCredential, nil
-		}
 		return auth.EmptyCredential, err
 	}
-	// bearer auth is used if the username is emptyUsername
+	var dockerCred dockerCredentials
+	if err := json.Unmarshal(out, &dockerCred); err != nil {
+		return auth.EmptyCredential, err
+	}
+	// bearer auth is used if the username is "<token>"
 	if dockerCred.Username == emptyUsername {
 		cred.RefreshToken = dockerCred.Secret
 	} else {
@@ -72,8 +84,8 @@ func (ns *nativeStore) Get(_ context.Context, serverAddress string) (auth.Creden
 }
 
 // Put saves credentials into the store.
-func (ns *nativeStore) Put(_ context.Context, serverAddress string, cred auth.Credential) error {
-	dockerCred := &credentials.Credentials{
+func (ns *nativeStore) Put(ctx context.Context, serverAddress string, cred auth.Credential) error {
+	dockerCred := &dockerCredentials{
 		ServerURL: serverAddress,
 		Username:  cred.Username,
 		Secret:    cred.Password,
@@ -82,12 +94,18 @@ func (ns *nativeStore) Put(_ context.Context, serverAddress string, cred auth.Cr
 		dockerCred.Username = emptyUsername
 		dockerCred.Secret = cred.RefreshToken
 	}
-	return client.Store(ns.programFunc, dockerCred)
+	credJSON, err := json.Marshal(dockerCred)
+	if err != nil {
+		return err
+	}
+	_, err = ns.exec.Execute(ctx, bytes.NewReader(credJSON), "store")
+	return err
 }
 
 // Delete removes credentials from the store for the given server.
-func (ns *nativeStore) Delete(_ context.Context, serverAddress string) error {
-	return client.Erase(ns.programFunc, serverAddress)
+func (ns *nativeStore) Delete(ctx context.Context, serverAddress string) error {
+	_, err := ns.exec.Execute(ctx, strings.NewReader(serverAddress), "erase")
+	return err
 }
 
 // getDefaultHelperSuffix returns the default credential helper suffix.

native_store_test.go

@@ -23,57 +23,59 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/docker/docker-credential-helpers/client"
-	"github.com/docker/docker-credential-helpers/credentials"
 	"oras.land/oras-go/v2/registry/remote/auth"
 )
 
 const (
 	basicAuthHost    = "localhost:2333"
 	bearerAuthHost   = "localhost:6666"
+	exeErrorHost     = "localhost:500/exeError"
+	jsonErrorHost    = "localhost:500/jsonError"
 	testUsername     = "test_username"
 	testPassword     = "test_password"
 	testRefreshToken = "test_token"
 )
 
 var (
 	errCommandExited = fmt.Errorf("exited with error")
+	exeErr           = fmt.Errorf("Execute failed")
 )
 
-// testCommand implements the Program interface for testing purpose.
+// testExecuter implements the Executer interface for testing purpose.
 // It simulates interactions between the docker client and a remote
 // credentials helper.
-type testCommand struct {
-	arg   string
-	input io.Reader
-}
+type testExecuter struct{}
 
-// Output returns responses from the remote credentials helper.
+// Execute returns responses from the remote credentials helper.
 // It mocks those responses based in the input in the mock.
-func (m *testCommand) Output() ([]byte, error) {
-	in, err := io.ReadAll(m.input)
+func (e *testExecuter) Execute(ctx context.Context, input io.Reader, action string) ([]byte, error) {
+	in, err := io.ReadAll(input)
 	if err != nil {
 		return nil, err
 	}
 	inS := string(in)
-	switch m.arg {
+	switch action {
 	case "get":
 		switch inS {
 		case basicAuthHost:
 			return []byte(`{"Username": "test_username", "Secret": "test_password"}`), nil
 		case bearerAuthHost:
 			return []byte(`{"Username": "<token>", "Secret": "test_token"}`), nil
+		case exeErrorHost:
+			return []byte("Execute failed"), exeErr
+		case jsonErrorHost:
+			return []byte("json.Unmarshal failed"), nil
 		default:
 			return []byte("program failed"), errCommandExited
 		}
 	case "store":
-		var c credentials.Credentials
+		var c dockerCredentials
 		err := json.NewDecoder(strings.NewReader(inS)).Decode(&c)
 		if err != nil {
 			return []byte("program failed"), errCommandExited
 		}
 		switch c.ServerURL {
-		case basicAuthHost, bearerAuthHost:
+		case basicAuthHost, bearerAuthHost, exeErrorHost:
 			return nil, nil
 		default:
 			return []byte("program failed"), errCommandExited
@@ -86,18 +88,7 @@ func (m *testCommand) Output() ([]byte, error) {
 			return []byte("program failed"), errCommandExited
 		}
 	}
-	return []byte(fmt.Sprintf("unknown argument %q with %q", m.arg, inS)), errCommandExited
-}
-
-// Input sets the input to send to a remote credentials helper.
-func (m *testCommand) Input(in io.Reader) {
-	m.input = in
-}
-
-func testCommandFn(args ...string) client.Program {
-	return &testCommand{
-		arg: args[0],
-	}
+	return []byte(fmt.Sprintf("unknown argument %q with %q", action, inS)), errCommandExited
 }
 
 func TestNativeStore_interface(t *testing.T) {
@@ -109,7 +100,7 @@ func TestNativeStore_interface(t *testing.T) {
 
 func TestNativeStore_basicAuth(t *testing.T) {
 	ns := &nativeStore{
-		programFunc: testCommandFn,
+		&testExecuter{},
 	}
 	// Put
 	err := ns.Put(context.Background(), basicAuthHost, auth.Credential{Username: testUsername, Password: testPassword})
@@ -136,7 +127,7 @@ func TestNativeStore_basicAuth(t *testing.T) {
 
 func TestNativeStore_refreshToken(t *testing.T) {
 	ns := &nativeStore{
-		programFunc: testCommandFn,
+		&testExecuter{},
 	}
 	// Put
 	err := ns.Put(context.Background(), bearerAuthHost, auth.Credential{RefreshToken: testRefreshToken})
@@ -160,3 +151,19 @@ func TestNativeStore_refreshToken(t *testing.T) {
 		t.Fatalf("refresh token test ns.Delete fails: %v", err)
 	}
 }
+
+func TestNativeStore_errorHandling(t *testing.T) {
+	ns := &nativeStore{
+		&testExecuter{},
+	}
+	// Get Error: Execute error
+	_, err := ns.Get(context.Background(), exeErrorHost)
+	if err != exeErr {
+		t.Fatalf("got error: %v, should get exeErr", err)
+	}
+	// Get Error: json.Unmarshal
+	_, err = ns.Get(context.Background(), jsonErrorHost)
+	if err == nil {
+		t.Fatalf("should get error from json.Unmarshal")
+	}
+}