3 files changed, 58 insertions, 0 deletions
diff --git a/runsc/test/testutil/BUILD b/runsc/test/testutil/BUILD
index ca91e07ff..da2535bfa 100644
--- a/runsc/test/testutil/BUILD
+++ b/runsc/test/testutil/BUILD
@@ -17,6 +17,7 @@ go_library(
         "//runsc/boot",
         "//runsc/specutils",
         "@com_github_cenkalti_backoff//:go_default_library",
+        "@com_github_kr_pty//:go_default_library",
         "@com_github_opencontainers_runtime-spec//specs-go:go_default_library",
         "@com_github_syndtr_gocapability//capability:go_default_library",
     ],
diff --git a/runsc/test/testutil/docker.go b/runsc/test/testutil/docker.go
index 7f5909987..55ca353b8 100644
--- a/runsc/test/testutil/docker.go
+++ b/runsc/test/testutil/docker.go
@@ -26,6 +26,8 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	"github.com/kr/pty"
 )
 
 func init() {
@@ -131,6 +133,17 @@ func do(args ...string) (string, error) {
 	return string(out), nil
 }
 
+// doWithPty executes docker command with stdio attached to a pty.
+func doWithPty(args ...string) (*exec.Cmd, *os.File, error) {
+	fmt.Printf("Running with pty: docker %s\n", args)
+	cmd := exec.Command("docker", args...)
+	ptmx, err := pty.Start(cmd)
+	if err != nil {
+		return nil, nil, fmt.Errorf("error executing docker %s with a pty: %v", args, err)
+	}
+	return cmd, ptmx, nil
+}
+
 // Pull pulls a docker image. This is used in tests to isolate the
 // time to pull the image off the network from the time to actually
 // start the container, to avoid timeouts over slow networks.
@@ -197,6 +210,14 @@ func (d *Docker) Exec(args ...string) (string, error) {
 	return do(a...)
 }
 
+// ExecWithTerminal calls 'docker exec -it' with the arguments provided and
+// attaches a pty to stdio.
+func (d *Docker) ExecWithTerminal(args ...string) (*exec.Cmd, *os.File, error) {
+	a := []string{"exec", "-it", d.Name}
+	a = append(a, args...)
+	return doWithPty(a...)
+}
+
 // Pause calls 'docker pause'.
 func (d *Docker) Pause() error {
 	if _, err := do("pause", d.Name); err != nil {
diff --git a/runsc/test/testutil/testutil.go b/runsc/test/testutil/testutil.go
index 07d66e469..cdc7f78c3 100644
--- a/runsc/test/testutil/testutil.go
+++ b/runsc/test/testutil/testutil.go
@@ -16,6 +16,7 @@
 package testutil
 
 import (
+	"bufio"
 	"context"
 	"encoding/json"
 	"fmt"
@@ -27,6 +28,8 @@ import (
 	"os/signal"
 	"path/filepath"
 	"runtime"
+	"strings"
+	"sync/atomic"
 	"syscall"
 	"time"
 
@@ -315,3 +318,36 @@ func RetryEintr(f func() (uintptr, uintptr, error)) (uintptr, uintptr, error) {
 		}
 	}
 }
+
+// WaitUntilRead reads from the given reader until the wanted string is found
+// or until timeout.
+func WaitUntilRead(r io.Reader, want string, split bufio.SplitFunc, timeout time.Duration) error {
+	sc := bufio.NewScanner(r)
+	if split != nil {
+		sc.Split(split)
+	}
+	// done must be accessed atomically. A value greater than 0 indicates
+	// that the read loop can exit.
+	var done uint32
+	doneCh := make(chan struct{})
+	go func() {
+		for sc.Scan() {
+			t := sc.Text()
+			if strings.Contains(t, want) {
+				atomic.StoreUint32(&done, 1)
+				close(doneCh)
+				break
+			}
+			if atomic.LoadUint32(&done) > 0 {
+				break
+			}
+		}
+	}()
+	select {
+	case <-time.After(timeout):
+		atomic.StoreUint32(&done, 1)
+		return fmt.Errorf("timeout waiting to read %q", want)
+	case <-doneCh:
+		return nil
+	}
+}