runtime: Move the resourcecontrol package one layer up

And try to reduce the number of virtcontainers packages, step by step.

Signed-off-by: Samuel Ortiz <s.ortiz@apple.com>

src/runtime/pkg/resourcecontrol/utils_linux_test.go

@@ -0,0 +1,160 @@
+// Copyright (c) 2020 Intel Corporation
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package resourcecontrol
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIsSystemdCgroup(t *testing.T) {
+	assert := assert.New(t)
+
+	tests := []struct {
+		path     string
+		expected bool
+	}{
+		{"foo.slice:kata:afhts2e5d4g5s", true},
+		{"system.slice:kata:afhts2e5d4g5s", true},
+		{"/kata/afhts2e5d4g5s", false},
+		{"a:b:c:d", false},
+		{":::", false},
+		{"", false},
+		{":", false},
+		{"::", false},
+		{":::", false},
+		{"a:b", false},
+		{"a:b:", false},
+		{":a:b", false},
+		{"@:@:@", false},
+	}
+
+	for _, t := range tests {
+		assert.Equal(t.expected, IsSystemdCgroup(t.path), "invalid systemd cgroup path: %v", t.path)
+	}
+}
+
+func TestValidCgroupPath(t *testing.T) {
+	assert := assert.New(t)
+
+	for _, t := range []struct {
+		path          string
+		systemdCgroup bool
+		error         bool
+	}{
+		// empty paths
+		{"../../../", false, false},
+		{"../", false, false},
+		{".", false, false},
+		{"../../../", false, false},
+		{"./../", false, false},
+
+		// valid no-systemd paths
+		{"../../../foo", false, false},
+		{"/../hi", false, false},
+		{"/../hi/foo", false, false},
+		{"o / m /../ g", false, false},
+		{"/overhead/foobar", false, false},
+		{"/sys/fs/cgroup/cpu/sandbox/kata_foobar", false, false},
+
+		// invalid systemd paths
+		{"o / m /../ g", true, true},
+		{"slice:kata", true, true},
+		{"/kata/afhts2e5d4g5s", true, true},
+		{"a:b:c:d", true, true},
+		{":::", true, true},
+		{"", true, true},
+		{":", true, true},
+		{"::", true, true},
+		{":::", true, true},
+		{"a:b", true, true},
+		{"a:b:", true, true},
+		{":a:b", true, true},
+		{"@:@:@", true, true},
+
+		// valid systemd paths
+		{"x.slice:kata:55555", true, false},
+		{"system.slice:kata:afhts2e5d4g5s", true, false},
+	} {
+		path, err := ValidCgroupPath(t.path, t.systemdCgroup)
+		if t.error {
+			assert.Error(err)
+			continue
+		} else {
+			assert.NoError(err)
+		}
+
+		if filepath.IsAbs(t.path) {
+			cleanPath := filepath.Dir(filepath.Clean(t.path))
+			assert.True(strings.HasPrefix(path, cleanPath),
+				"%v should have prefix %v", path, cleanPath)
+		} else if t.systemdCgroup {
+			assert.Equal(t.path, path)
+		} else {
+			assert.True(
+				strings.HasPrefix(path, DefaultResourceControllerID),
+				"%v should have prefix /%v", path, DefaultResourceControllerID)
+		}
+	}
+
+}
+
+func TestDeviceToCgroupDeviceRule(t *testing.T) {
+	assert := assert.New(t)
+
+	f, err := os.CreateTemp("", "device")
+	assert.NoError(err)
+	f.Close()
+
+	// fail: regular file to device
+	dev, err := DeviceToCgroupDeviceRule(f.Name())
+	assert.Error(err)
+	assert.Nil(dev)
+
+	// fail: no such file
+	os.Remove(f.Name())
+	dev, err = DeviceToCgroupDeviceRule(f.Name())
+	assert.Error(err)
+	assert.Nil(dev)
+
+	devPath := "/dev/null"
+	if _, err := os.Stat(devPath); os.IsNotExist(err) {
+		t.Skipf("no such device: %v", devPath)
+		return
+	}
+	dev, err = DeviceToCgroupDeviceRule(devPath)
+	assert.NoError(err)
+	assert.NotNil(dev)
+	assert.Equal(rune(dev.Type), 'c')
+	assert.NotZero(dev.Major)
+	assert.NotZero(dev.Minor)
+	assert.NotEmpty(dev.Permissions)
+	assert.True(dev.Allow)
+}
+
+func TestDeviceToLinuxDevice(t *testing.T) {
+	assert := assert.New(t)
+
+	devPath := "/dev/null"
+	if _, err := os.Stat(devPath); os.IsNotExist(err) {
+		t.Skipf("no such device: %v", devPath)
+		return
+	}
+	dev, err := DeviceToLinuxDevice(devPath)
+	assert.NoError(err)
+	assert.NotNil(dev)
+	assert.Equal(dev.Type, "c")
+	assert.NotNil(dev.Major)
+	assert.NotZero(*dev.Major)
+	assert.NotNil(dev.Minor)
+	assert.NotZero(*dev.Minor)
+	assert.NotEmpty(dev.Access)
+	assert.True(dev.Allow)
+}