Function TestSignalProcessGroup

runsc/container/container_test.go:1083–1165

TestSignalProcessGroup verifies that SignalProcessGroup kills all processes in the targeted process group while leaving other groups running.

(t *testing.T)

// processes in the targeted process group while leaving other groups
// running.
func TestSignalProcessGroup(t *testing.T) {
	for name, conf := range configs(t, false /* noOverlay */) {
		t.Run(name, func(t *testing.T) {
			app, err := testutil.FindFile("test/cmd/test_app/test_app")
			if err != nil {
				t.Fatal("error finding test_app:", err)
			}

			spec := testutil.NewSpecWithArgs(app, "task-tree-pgid")
			_, bundleDir, cleanup, err := testutil.SetupContainer(spec, conf)
			if err != nil {
				t.Fatalf("error setting up container: %v", err)
			}
			defer cleanup()

			args := Args{
				ID:        testutil.RandomContainerID(),
				Spec:      spec,
				BundleDir: bundleDir,
			}
			cont, err := New(conf, args)
			if err != nil {
				t.Fatalf("error creating container: %v", err)
			}
			defer cont.Destroy()
			if err := cont.Start(conf); err != nil {
				t.Fatalf("error starting container: %v", err)
			}

			// Wait for all 3 processes: init, child, grandchild.
			if err := waitForProcessCount(cont, 3); err != nil {
				t.Fatalf("timed out waiting for processes: %v", err)
			}

			// Collect PGIDs.
			procs, err := cont.Processes()
			if err != nil {
				t.Fatalf("failed to get process list: %v", err)
			}
			t.Logf("before signal: %s", procListToString(procs))

			// Init (PID 1) is in PGID 1.
			// Child + grandchild should share a PGID != 1.
			pgidA := int32(1)
			pgidBCount := make(map[int32]int)
			for _, p := range procs {
				if int32(p.PGID) != pgidA {
					pgidBCount[int32(p.PGID)]++
				}
			}

			// Find the PGID shared by child+grandchild.
			var pgidB int32
			for pgid, n := range pgidBCount {
				if n == 2 {
					pgidB = pgid
				}
			}