Add TestZombies and improve exec output handling

test/docker/docker_api_test.go

@@ -17,6 +17,7 @@ package main
 
 import (
 	"context"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -270,3 +271,38 @@ func TestVolumeUnmount(t *testing.T) {
 		t.Logf(execContainerWithOutput(t, cli, ctr.ID, "mqm", []string{"ps", "-ef"}))
 	}
 }
+
+// TestZombies starts a queue manager, then causes a zombie process to be
+// created, then checks that no zombies exist (runmqserver should reap them)
+func TestZombies(t *testing.T) {
+	cli, err := client.NewEnvClient()
+	if err != nil {
+		t.Fatal(err)
+	}
+	containerConfig := container.Config{
+		Env: []string{"LICENSE=accept", "MQ_QMGR_NAME=qm1", "DEBUG=true"},
+		//ExposedPorts: ports,
+		ExposedPorts: nat.PortSet{
+			"1414/tcp": struct{}{},
+		},
+	}
+	id := runContainer(t, cli, &containerConfig)
+	defer cleanContainer(t, cli, id)
+	waitForReady(t, cli, id)
+	// Kill an MQ process with children.  After it is killed, its children
+	// will be adopted by PID 1, and should then be reaped when they die.
+	out := execContainerWithOutput(t, cli, id, "mqm", []string{"pkill", "--signal", "kill", "-c", "amqzxma0"})
+	if out == "0" {
+		t.Fatalf("Expected pkill to kill a process, got %v", out)
+	}
+	time.Sleep(3 * time.Second)
+	// Create a zombie process for up to ten seconds
+	out = execContainerWithOutput(t, cli, id, "mqm", []string{"bash", "-c", "ps -lA | grep '^. Z' | wc -l"})
+	count, err := strconv.Atoi(out)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if count != 0 {
+		t.Fatalf("Expected zombies=0, got %v", count)
+	}
+}

test/docker/docker_api_test_util.go

@@ -23,6 +23,7 @@ import (
 	"os"
 	"path/filepath"
 	"strconv"
+	"strings"
 	"testing"
 	"time"
 
@@ -32,6 +33,7 @@ import (
 	"github.com/docker/docker/api/types/volume"
 	"github.com/docker/docker/client"
 	"github.com/docker/go-connections/nat"
+	"github.com/moby/moby/pkg/stdcopy"
 )
 
 func imageName() string {
@@ -241,13 +243,13 @@ func execContainerWithOutput(t *testing.T, cli *client.Client, ID string, user s
 	if err != nil {
 		t.Fatal(err)
 	}
-	// TODO: For some reason, each line seems to start with an extra, random character
-	buf, err := ioutil.ReadAll(hijack.Reader)
+	buf := new(bytes.Buffer)
+	// Each output line has a header, which needs to be removed
+	_, err = stdcopy.StdCopy(buf, buf, hijack.Reader)
 	if err != nil {
-		t.Fatal(err)
+		log.Fatal(err)
 	}
-	hijack.Close()
-	return string(buf)
+	return strings.TrimSpace(buf.String())
 }
 
 func waitForReady(t *testing.T, cli *client.Client, ID string) {
@@ -320,8 +322,11 @@ func inspectLogs(t *testing.T, cli *client.Client, ID string) string {
 	if err != nil {
 		log.Fatal(err)
 	}
-
 	buf := new(bytes.Buffer)
-	buf.ReadFrom(reader)
+	// Each output line has a header, which needs to be removed
+	_, err = stdcopy.StdCopy(buf, buf, reader)
+	if err != nil {
+		log.Fatal(err)
+	}
 	return buf.String()
 }