Implement TTY field in control.Processes().

Threadgroups already know their TTY (if they have one), which now contains the
TTY Index, and is returned in the Processes() call.

PiperOrigin-RevId: 284263850

2 files changed, 41 insertions, 0 deletions

diff --git a/runsc/container/test_app/BUILD b/runsc/container/test_app/BUILD
index 9bf9e6e9d..bfd338bb6 100644
--- a/runsc/container/test_app/BUILD
+++ b/runsc/container/test_app/BUILD
@@ -15,5 +15,6 @@ go_binary(
         "//pkg/unet",
         "//runsc/testutil",
         "@com_github_google_subcommands//:go_default_library",
+        "@com_github_kr_pty//:go_default_library",
     ],
 )
diff --git a/runsc/container/test_app/test_app.go b/runsc/container/test_app/test_app.go
index 913d781c6..a1c8a741a 100644
--- a/runsc/container/test_app/test_app.go
+++ b/runsc/container/test_app/test_app.go
@@ -19,6 +19,7 @@ package main
 import (
 	"context"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"log"
 	"net"
@@ -31,6 +32,7 @@ import (
 
 	"flag"
 	"github.com/google/subcommands"
+	"github.com/kr/pty"
 	"gvisor.dev/gvisor/runsc/testutil"
 )
 
@@ -41,6 +43,7 @@ func main() {
 	subcommands.Register(new(fdReceiver), "")
 	subcommands.Register(new(fdSender), "")
 	subcommands.Register(new(forkBomb), "")
+	subcommands.Register(new(ptyRunner), "")
 	subcommands.Register(new(reaper), "")
 	subcommands.Register(new(syscall), "")
 	subcommands.Register(new(taskTree), "")
@@ -352,3 +355,40 @@ func (c *capability) Execute(ctx context.Context, f *flag.FlagSet, args ...inter
 
 	return subcommands.ExitSuccess
 }
+
+type ptyRunner struct{}
+
+// Name implements subcommands.Command.
+func (*ptyRunner) Name() string {
+	return "pty-runner"
+}
+
+// Synopsis implements subcommands.Command.
+func (*ptyRunner) Synopsis() string {
+	return "runs the given command with an open pty terminal"
+}
+
+// Usage implements subcommands.Command.
+func (*ptyRunner) Usage() string {
+	return "pty-runner [command]"
+}
+
+// SetFlags implements subcommands.Command.SetFlags.
+func (*ptyRunner) SetFlags(f *flag.FlagSet) {}
+
+// Execute implements subcommands.Command.
+func (*ptyRunner) Execute(_ context.Context, fs *flag.FlagSet, _ ...interface{}) subcommands.ExitStatus {
+	c := exec.Command(fs.Args()[0], fs.Args()[1:]...)
+	f, err := pty.Start(c)
+	if err != nil {
+		fmt.Printf("pty.Start failed: %v", err)
+		return subcommands.ExitFailure
+	}
+	defer f.Close()
+
+	// Copy stdout from the command to keep this process alive until the
+	// subprocess exits.
+	io.Copy(os.Stdout, f)
+
+	return subcommands.ExitSuccess
+}