login: add e2e tests for oauth + escape hatch

Signed-off-by: Laura Brehm <laurabrehm@hey.com>
(cherry picked from commit a327476f7f)
Signed-off-by: Laura Brehm <laurabrehm@hey.com>

e2e/registry/login_test.go

@@ -0,0 +1,56 @@
+package registry
+
+import (
+	"io"
+	"os/exec"
+	"strings"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/creack/pty"
+	"gotest.tools/v3/assert"
+)
+
+func TestOauthLogin(t *testing.T) {
+	t.Parallel()
+	loginCmd := exec.Command("docker", "login")
+
+	p, err := pty.Start(loginCmd)
+	assert.NilError(t, err)
+	defer func() {
+		_ = loginCmd.Wait()
+		_ = p.Close()
+	}()
+
+	time.Sleep(1 * time.Second)
+	pid := loginCmd.Process.Pid
+	t.Logf("terminating PID %d", pid)
+	err = syscall.Kill(pid, syscall.SIGTERM)
+	assert.NilError(t, err)
+
+	output, _ := io.ReadAll(p)
+	assert.Check(t, strings.Contains(string(output), "USING WEB BASED LOGIN"), string(output))
+}
+
+func TestLoginWithEscapeHatch(t *testing.T) {
+	t.Parallel()
+	loginCmd := exec.Command("docker", "login")
+	loginCmd.Env = append(loginCmd.Env, "DOCKER_CLI_DISABLE_OAUTH_LOGIN=1")
+
+	p, err := pty.Start(loginCmd)
+	assert.NilError(t, err)
+	defer func() {
+		_ = loginCmd.Wait()
+		_ = p.Close()
+	}()
+
+	time.Sleep(1 * time.Second)
+	pid := loginCmd.Process.Pid
+	t.Logf("terminating PID %d", pid)
+	err = syscall.Kill(pid, syscall.SIGTERM)
+	assert.NilError(t, err)
+
+	output, _ := io.ReadAll(p)
+	assert.Check(t, strings.Contains(string(output), "Username:"), string(output))
+}

e2e/registry/main_test.go

@@ -0,0 +1,17 @@
+package registry
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/docker/cli/internal/test/environment"
+)
+
+func TestMain(m *testing.M) {
+	if err := environment.Setup(); err != nil {
+		fmt.Println(err.Error())
+		os.Exit(3)
+	}
+	os.Exit(m.Run())
+}