fix(exec): don't steal stdin when stdout is not a TTY

cmd/compose/exec.go

@@ -83,10 +83,11 @@ func execCommand(p *ProjectOptions, dockerCli command.Cli, backendOptions *Backe
 	runCmd.Flags().IntVar(&opts.index, "index", 0, "Index of the container if service has multiple replicas")
 	runCmd.Flags().BoolVarP(&opts.privileged, "privileged", "", false, "Give extended privileges to the process")
 	runCmd.Flags().StringVarP(&opts.user, "user", "u", "", "Run the command as this user")
-	runCmd.Flags().BoolVarP(&opts.noTty, "no-tty", "T", !dockerCli.Out().IsTerminal(), "Disable pseudo-TTY allocation. By default 'docker compose exec' allocates a TTY.")
+	isTTY := dockerCli.Out().IsTerminal()
+	runCmd.Flags().BoolVarP(&opts.noTty, "no-tty", "T", !isTTY, "Disable pseudo-TTY allocation. By default 'docker compose exec' allocates a TTY.")
 	runCmd.Flags().StringVarP(&opts.workingDir, "workdir", "w", "", "Path to workdir directory for this command")
 
-	runCmd.Flags().BoolVarP(&opts.interactive, "interactive", "i", true, "Keep STDIN open even if not attached")
+	runCmd.Flags().BoolVarP(&opts.interactive, "interactive", "i", isTTY, "Keep STDIN open even if not attached")
 	runCmd.Flags().MarkHidden("interactive") //nolint:errcheck
 	runCmd.Flags().BoolP("tty", "t", true, "Allocate a pseudo-TTY")
 	runCmd.Flags().MarkHidden("tty") //nolint:errcheck

cmd/compose/exec_test.go

@@ -0,0 +1,44 @@
+/*
+   Copyright 2020 Docker Compose CLI 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 compose
+
+import (
+	"os"
+	"testing"
+
+	"github.com/docker/cli/cli/streams"
+	"go.uber.org/mock/gomock"
+	"gotest.tools/v3/assert"
+
+	"github.com/docker/compose/v5/pkg/mocks"
+)
+
+func TestExecInteractiveDefaultOffWhenStdoutNotTTY(t *testing.T) {
+	r, w, err := os.Pipe()
+	assert.NilError(t, err)
+	t.Cleanup(func() {
+		_ = r.Close()
+		_ = w.Close()
+	})
+
+	cli := mocks.NewMockCli(gomock.NewController(t))
+	cli.EXPECT().Out().Return(streams.NewOut(w)).AnyTimes()
+
+	cmd := execCommand(&ProjectOptions{}, cli, &BackendOptions{})
+	assert.Equal(t, cmd.Flags().Lookup("interactive").DefValue, "false")
+	assert.Equal(t, cmd.Flags().Lookup("no-tty").DefValue, "true")
+}