add test cases for cgroupfs / systemd

comp/core/workloadmeta/collectors/internal/containerd/container_builder.go

@@ -136,13 +136,7 @@ func buildWorkloadMetaContainer(namespace string, container containerd.Container
 		workloadContainer.EnvVars = envs
 		workloadContainer.Hostname = spec.Hostname
 		if spec.Linux != nil {
-			// Containerd applies some transformations to the cgroup path, we need to revert them
-			// https://github.com/containerd/containerd/blob/b168147ca8fccf05003117324f493d40f97b6077/internal/cri/server/podsandbox/helpers_linux.go#L64-L65
-			// See https://github.com/opencontainers/runc/blob/main/docs/systemd.md
-			workloadContainer.CgroupPath = spec.Linux.CgroupsPath
-			if l := strings.Split(workloadContainer.CgroupPath, ":"); len(l) == 3 {
-				workloadContainer.CgroupPath = l[0] + "/" + l[1] + "-" + l[2] + ".scope"
-			}
+			workloadContainer.CgroupPath = extractCgroupPath(spec.Linux.CgroupsPath)
 		}
 	} else if errors.Is(err, cutil.ErrSpecTooLarge) {
 		log.Warnf("Skipping parsing of container spec for container id: %s, spec is bigger than: %d", info.ID, cutil.DefaultAllowedSpecMaxSize)
@@ -153,6 +147,17 @@ func buildWorkloadMetaContainer(namespace string, container containerd.Container
 	return workloadContainer, nil
 }
 
+// Containerd applies some transformations to the cgroup path, we need to revert them
+// https://github.com/containerd/containerd/blob/b168147ca8fccf05003117324f493d40f97b6077/internal/cri/server/podsandbox/helpers_linux.go#L64-L65
+// See https://github.com/opencontainers/runc/blob/main/docs/systemd.md
+func extractCgroupPath(path string) string {
+	res := path
+	if l := strings.Split(path, ":"); len(l) == 3 {
+		res = l[0] + "/" + l[1] + "-" + l[2] + ".scope"
+	}
+	return res
+}
+
 func extractStatus(status containerd.ProcessStatus) workloadmeta.ContainerStatus {
 	switch status {
 	case containerd.Paused, containerd.Pausing:

comp/core/workloadmeta/collectors/internal/containerd/container_builder_test.go

@@ -182,6 +182,44 @@ func TestBuildWorkloadMetaContainer(t *testing.T) {
 	assert.Equal(t, expected, result)
 }
 
+func TestExtractCgroupPath(t *testing.T) {
+	tests := []struct {
+		name     string
+		path     string
+		expected string
+	}{
+		// cgroupfs retrieved using minikube + qemu2 driver
+		{
+			name:     "cgroupfs + kubernetes pod",
+			path:     "/kubepods/burstable/pod84a7cac1-5690-4935-bffc-4b808e0240e4/0af39253daf5d1054519efdd054023e929785c2813c29f6a0ce887f652e1a997",
+			expected: "/kubepods/burstable/pod84a7cac1-5690-4935-bffc-4b808e0240e4/0af39253daf5d1054519efdd054023e929785c2813c29f6a0ce887f652e1a997",
+		},
+		// systemd retrieved using kind
+		{
+			name:     "systemd + kubernetes pod",
+			path:     "kubelet-kubepods-burstable-pod99dcb84d2a34f7e338778606703258c4.slice:cri-containerd:ec9ea0ad54dd0d96142d5dbe11eb3f1509e12ba9af739620c7b5ad377ce94602",
+			expected: "kubelet-kubepods-burstable-pod99dcb84d2a34f7e338778606703258c4.slice/cri-containerd-ec9ea0ad54dd0d96142d5dbe11eb3f1509e12ba9af739620c7b5ad377ce94602.scope",
+		},
+		// custom retrieved using ctr run
+		{
+			name:     "systemd/cgroupfs + container",
+			path:     "/default/redis",
+			expected: "/default/redis",
+		},
+		// garden
+		{
+			name:     "garden",
+			path:     "/garden/1a65c217-84b2-8d13-3d78-46b14b6c7ea1",
+			expected: "/garden/1a65c217-84b2-8d13-3d78-46b14b6c7ea1",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.expected, extractCgroupPath(tt.path))
+		})
+	}
+}
+
 func TestExtractRuntimeFlavor(t *testing.T) {
 	tests := []struct {
 		name     string