feat: manage task process lifetimes and preserve turn history

internal/processguard/cgroup_linux_test.go

@@ -0,0 +1,120 @@
+//go:build linux
+
+package processguard
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func TestCgroupContainsSetsidAndAppliesLimits(t *testing.T) {
+	opts := testOptions()
+	if opts.CgroupRoot == "" {
+		t.Skip("set CSAI_TEST_CGROUP_ROOT to a delegated cgroup v2 root")
+	}
+	opts.Mode = "required"
+	opts.CPUQuotaMicros = 50000
+	id := testID()
+	g, err := NewWithOptions(id, opts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer closeTestGroup(t, g)
+	file := filepath.Join(t.TempDir(), "escaped")
+	cmd, err := startTestCommand(g, fmt.Sprintf("setsid sh -c 'echo $$ > %s; exec sleep 300' </dev/null >/dev/null 2>&1 &", file))
+	if err != nil {
+		t.Fatal(err)
+	}
+	reaped := make(chan struct{})
+	go func() { _ = cmd.Wait(); close(reaped) }()
+	pid := readPID(t, file)
+	<-reaped // The launching shell is gone; the cgroup must still own setsid descendants.
+	root := filepath.Join(opts.CgroupRoot, "task-"+id)
+	for name, want := range map[string]string{"pids.max": "64", "memory.max": "268435456", "cpu.max": "50000 100000"} {
+		data, err := os.ReadFile(filepath.Join(root, name))
+		if err != nil || strings.TrimSpace(string(data)) != want {
+			t.Fatalf("%s=%s err=%v", name, data, err)
+		}
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	if err = g.Close(ctx); err != nil {
+		t.Fatal(err)
+	}
+	<-reaped
+	waitGone(t, pid)
+	if _, err = os.Stat(root); !os.IsNotExist(err) {
+		t.Fatalf("cgroup retained after cleanup: %v", err)
+	}
+}
+
+func TestCgroupStartupDelegationAndRecovery(t *testing.T) {
+	opts := testOptions()
+	if opts.CgroupRoot == "" {
+		t.Skip("requires delegated cgroup fixture")
+	}
+	before, err := os.ReadFile("/proc/self/cgroup")
+	if err != nil {
+		t.Fatal(err)
+	}
+	original := ""
+	for _, line := range strings.Split(string(before), "\n") {
+		if strings.HasPrefix(line, "0::") {
+			original = filepath.Join("/sys/fs/cgroup", strings.TrimPrefix(line, "0::"))
+		}
+	}
+	root := filepath.Join(opts.CgroupRoot, "startup-fixture")
+	if err = os.Mkdir(root, 0700); err != nil {
+		t.Fatal(err)
+	}
+	if err = os.WriteFile(filepath.Join(root, "cgroup.procs"), []byte(fmt.Sprint(os.Getpid())), 0600); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		_ = os.WriteFile(filepath.Join(original, "cgroup.procs"), []byte(fmt.Sprint(os.Getpid())), 0600)
+		if rootLock != nil {
+			_ = rootLock.Close()
+			rootLock = nil
+		}
+		_ = removeCgroupTree(root)
+	}()
+	stale := filepath.Join(root, "task-"+testID())
+	if err = os.Mkdir(stale, 0700); err != nil {
+		t.Fatal(err)
+	}
+	dir, err := os.Open(stale)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dir.Close()
+	cmd := exec.Command("sh", "-c", "exec sleep 300")
+	cmd.SysProcAttr = &syscall.SysProcAttr{UseCgroupFD: true, CgroupFD: int(dir.Fd()), Setsid: true}
+	if err = cmd.Start(); err != nil {
+		t.Fatal(err)
+	}
+	reaped := make(chan struct{})
+	go func() { _ = cmd.Wait(); close(reaped) }()
+	opts.CgroupRoot = root
+	opts.Mode = "required"
+	if err = configurePlatform(&opts); err != nil {
+		_ = cmd.Process.Kill()
+		<-reaped
+		t.Fatal(err)
+	}
+	<-reaped
+	waitGone(t, cmd.Process.Pid)
+	if _, err = os.Stat(stale); !os.IsNotExist(err) {
+		t.Fatalf("stale task cgroup was not removed: %v", err)
+	}
+	data, err := os.ReadFile(filepath.Join(root, "cgroup.subtree_control"))
+	if err != nil || !strings.Contains(string(data), "memory") {
+		t.Fatalf("delegation not enabled: %s %v", data, err)
+	}
+}