tests:cgroups: ensure that we get cgroup mkdir and rmdir events

This test ensure that we get bpf events when cgroup mkdir and rmdir
happen, also it includes extended logic to track if the cgroup data
is correct inside bpf map and if it was removed from the same cgroup
tracking map after cgroup_rmmdir.

Author: tixxdz

pkg/sensors/exec/cgroups_test.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/cilium/tetragon/pkg/api/ops"
+	"github.com/cilium/tetragon/pkg/api/processapi"
 	"github.com/cilium/tetragon/pkg/cgroups"
 	grpcexec "github.com/cilium/tetragon/pkg/grpc/exec"
 	"github.com/cilium/tetragon/pkg/sensors"
@@ -20,6 +21,7 @@ import (
 	"github.com/cilium/tetragon/pkg/observer"
 	"github.com/cilium/tetragon/pkg/option"
 	"github.com/cilium/tetragon/pkg/sensors/base"
+	"github.com/cilium/tetragon/pkg/sensors/cgroup/cgrouptrackmap"
 	testsensor "github.com/cilium/tetragon/pkg/sensors/test"
 	"github.com/cilium/tetragon/pkg/testutils"
 	"github.com/cilium/tetragon/pkg/testutils/perfring"
@@ -200,3 +202,114 @@ func TestCgroupNoEvents(t *testing.T) {
 		}
 	}
 }
+
+// Ensure that we get cgroup_{mkdir|rmdir} events
+func TestCgroupEventMkdirRmdir(t *testing.T) {
+	testutils.CaptureLog(t, logger.GetLogger().(*logrus.Logger))
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTimeout)
+	defer cancel()
+
+	option.Config.HubbleLib = tus.Conf().TetragonLib
+	option.Config.Verbosity = 5
+
+	_, err := observer.GetDefaultObserver(t, ctx, tus.Conf().TetragonLib)
+	if err != nil {
+		t.Fatalf("GetDefaultObserver error: %s", err)
+	}
+
+	testManager := tus.StartTestSensorManager(ctx, t)
+	observer.SensorManager = testManager.Manager
+
+	testManager.AddAndEnableSensors(ctx, t, loadedSensors)
+
+	// Set Tracking level to 3 so we receive notifcations about
+	// /sys/fs/cgroup/$1/$2/$3 all cgroups that are at level <=3
+	trackingCgrpLevel := uint32(3)
+	setupTgRuntimeConf(t, trackingCgrpLevel, uint32(logrus.TraceLevel))
+
+	cgroupFSPath := cgroups.GetCgroupFSPath()
+	assert.NotEmpty(t, cgroupFSPath)
+
+	dir, hierarchy := getTestCgroupDirAndHierarchy(t)
+	cgroupRmdir(t, cgroupFSPath, hierarchy, tetragonCgrpRoot)
+
+	matchedPath := dir
+	finalPath := filepath.Join(cgroupFSPath, hierarchy, dir)
+	_, err = os.Stat(finalPath)
+	if err == nil {
+		t.Fatalf("Test %s failed cgroup test hierarchy should not exist '%s'", t.Name(), finalPath)
+	}
+
+	t.Cleanup(func() {
+		cgroupRmdir(t, cgroupFSPath, hierarchy, dir)
+	})
+
+	trigger := func() {
+		err = cgroupMkdir(t, cgroupFSPath, hierarchy, dir)
+		assert.NoError(t, err)
+
+		err = cgroupRmdir(t, cgroupFSPath, hierarchy, dir)
+		assert.NoError(t, err)
+	}
+
+	mkdir := false
+	rmdir := false
+	cgrpMap := testsensor.GetCgroupsTrackingMap()
+	cgrpMapPath := filepath.Join(bpf.MapPrefixPath(), cgrpMap.Name)
+	cgrpTrackingId := uint64(0)
+	events := perfring.RunTestEvents(t, ctx, trigger)
+	for _, ev := range events {
+		if msg, ok := ev.(*grpcexec.MsgCgroupEventUnix); ok {
+			if msg.Common.Op == ops.MSG_OP_CGROUP {
+				cgrpPath := cgroups.CgroupNameFromCStr(msg.Path[:processapi.CGROUP_PATH_LENGTH])
+				op := ops.CgroupOpCode(msg.CgrpOp)
+				st := ops.CgroupState(msg.CgrpData.State).String()
+				logger.GetLogger().WithFields(logrus.Fields{
+					"cgroup.event":     op.String(),
+					"PID":              msg.PID,
+					"NSPID":            msg.NSPID,
+					"cgroup.IDTracker": msg.CgrpidTracker,
+					"cgroup.ID":        msg.Cgrpid,
+					"cgroup.state":     st,
+					"cgroup.level":     msg.CgrpData.Level,
+					"cgroup.path":      cgrpPath,
+				}).Info("Received Cgroup event")
+
+				assert.NotZero(t, msg.PID)
+				assert.NotZero(t, msg.Cgrpid)
+				assert.NotZero(t, msg.CgrpidTracker)
+				assert.NotEqualValues(t, msg.CgrpData.State, ops.CGROUP_UNTRACKED)
+				assert.NotZero(t, msg.CgrpData.Level)
+
+				switch op {
+				case ops.MSG_OP_CGROUP_MKDIR:
+					assert.EqualValues(t, ops.CGROUP_NEW, msg.CgrpData.State)
+					// Match only our test
+					if cgrpPath == matchedPath {
+						cgrpName := cgroups.CgroupNameFromCStr(msg.CgrpData.Name[:processapi.CGROUP_NAME_LENGTH])
+						assert.EqualValues(t, t.Name(), cgrpName)
+
+						mkdir = true
+						cgrpTrackingId = msg.CgrpidTracker
+					}
+				case ops.MSG_OP_CGROUP_RMDIR:
+					// Match only our test
+					if cgrpPath == matchedPath {
+						cgrpName := cgroups.CgroupNameFromCStr(msg.CgrpData.Name[:processapi.CGROUP_NAME_LENGTH])
+						assert.EqualValues(t, t.Name(), cgrpName)
+						rmdir = true
+					}
+				}
+			}
+		}
+	}
+
+	// Ensure that we received proper events
+	assert.Equal(t, true, mkdir)
+	assert.Equal(t, true, rmdir)
+	assert.NotZero(t, true, cgrpTrackingId)
+
+	// Should be removed from the tracking map
+	_, err = cgrouptrackmap.LookupTrackingCgroup(cgrpMapPath, cgrpTrackingId)
+	assert.Error(t, err)
+}