Make sandbox join the pod cgroup in K8s

cgroups in K8s are setup with the following hierarchy: `.../pod/container`.
The sandbox is created with the first container and consequently uses the
the pause container cgroup. This change removes the container cgroup from
the path to make the sandbox use the pod cgroup instead. Otherwise limits
set to the pause container will apply to the entire sandbox.

PiperOrigin-RevId: 374273277

1 files changed, 121 insertions, 0 deletions

diff --git a/pkg/shim/service_test.go b/pkg/shim/service_test.go
new file mode 100644
index 000000000..2d9f07e02
--- /dev/null
+++ b/pkg/shim/service_test.go
@@ -0,0 +1,121 @@
+// Copyright 2021 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shim
+
+import (
+	"testing"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"gvisor.dev/gvisor/pkg/shim/utils"
+)
+
+func TestCgroupPath(t *testing.T) {
+	for _, tc := range []struct {
+		name string
+		path string
+		want string
+	}{
+		{
+			name: "simple",
+			path: "foo/pod123/container",
+			want: "foo/pod123",
+		},
+		{
+			name: "absolute",
+			path: "/foo/pod123/container",
+			want: "/foo/pod123",
+		},
+		{
+			name: "no-container",
+			path: "foo/pod123",
+			want: "foo/pod123",
+		},
+		{
+			name: "no-container-absolute",
+			path: "/foo/pod123",
+			want: "/foo/pod123",
+		},
+		{
+			name: "double-pod",
+			path: "/foo/podium/pod123/container",
+			want: "/foo/podium/pod123",
+		},
+		{
+			name: "start-pod",
+			path: "pod123/container",
+			want: "pod123",
+		},
+		{
+			name: "start-pod-absolute",
+			path: "/pod123/container",
+			want: "/pod123",
+		},
+		{
+			name: "slashes",
+			path: "///foo/////pod123//////container",
+			want: "/foo/pod123",
+		},
+		{
+			name: "no-pod",
+			path: "/foo/nopod123/container",
+			want: "/foo/nopod123/container",
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			spec := specs.Spec{
+				Linux: &specs.Linux{
+					CgroupsPath: tc.path,
+				},
+			}
+			updated := updateCgroup(&spec)
+			if spec.Linux.CgroupsPath != tc.want {
+				t.Errorf("updateCgroup(%q), want: %q, got: %q", tc.path, tc.want, spec.Linux.CgroupsPath)
+			}
+			if shouldUpdate := tc.path != tc.want; shouldUpdate != updated {
+				t.Errorf("updateCgroup(%q)=%v, want: %v", tc.path, updated, shouldUpdate)
+			}
+		})
+	}
+}
+
+// Test cases that cgroup path should not be updated.
+func TestCgroupNoUpdate(t *testing.T) {
+	for _, tc := range []struct {
+		name string
+		spec *specs.Spec
+	}{
+		{
+			name: "empty",
+			spec: &specs.Spec{},
+		},
+		{
+			name: "subcontainer",
+			spec: &specs.Spec{
+				Linux: &specs.Linux{
+					CgroupsPath: "foo/pod123/container",
+				},
+				Annotations: map[string]string{
+					utils.ContainerTypeAnnotation: utils.ContainerTypeContainer,
+				},
+			},
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			if updated := updateCgroup(tc.spec); updated {
+				t.Errorf("updateCgroup(%+v), got: %v, want: false", tc.spec.Linux, updated)
+			}
+		})
+	}
+}