*: introduce wrapper pkgs for blockio and rdt

Before this patch, both the RdtEnabled and BlockIOEnabled are provided
by services/tasks pkg. Since the services/tasks can be pkg plugin which
can be initialized multiple times or concurrently. It will fire data-race
issue as there is no mutex to protect `enable`.

This patch is aimed to provide wrapper pkgs to use intel/{blockio,rdt}
safely.

Signed-off-by: Wei Fu <fuweid89@gmail.com>

pkg/rdt/rdt_default.go

@@ -0,0 +1,30 @@
+//go:build !linux || no_rdt
+
+/*
+   Copyright The containerd 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
+
+       http://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 rdt
+
+// IsEnabled always returns false in non-linux platforms.
+func IsEnabled() bool { return false }
+
+// SetConfig always is no-op in non-linux platforms.
+func SetConfig(configFilePath string) error { return nil }
+
+// ContainerClassFromAnnotations always is no-op in non-linux platforms.
+func ContainerClassFromAnnotations(containerName string, containerAnnotations, podAnnotations map[string]string) (string, error) {
+	return "", nil
+}

pkg/rdt/rdt_linux.go

@@ -0,0 +1,85 @@
+//go:build linux && !no_rdt
+
+/*
+   Copyright The containerd 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
+
+       http://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 rdt
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/containerd/containerd/log"
+
+	"github.com/intel/goresctrl/pkg/rdt"
+)
+
+const (
+	// ResctrlPrefix is the prefix used for class/closid directories under the resctrl filesystem
+	ResctrlPrefix = ""
+)
+
+var (
+	enabled   bool
+	enabledMu sync.RWMutex
+)
+
+// IsEnabled checks whether rdt is enabled.
+func IsEnabled() bool {
+	enabledMu.RLock()
+	defer enabledMu.RUnlock()
+
+	return enabled
+}
+
+var (
+	initOnce sync.Once
+	initErr  error
+)
+
+// SetConfig updates rdt config with a given config path.
+func SetConfig(configFilePath string) error {
+	enabledMu.Lock()
+	defer enabledMu.Unlock()
+
+	enabled = false
+	if configFilePath == "" {
+		log.L.Debug("No RDT config file specified, RDT not configured")
+		return nil
+	}
+
+	initOnce.Do(func() {
+		err := rdt.Initialize(ResctrlPrefix)
+		if err != nil {
+			initErr = fmt.Errorf("RDT not enabled: %w", err)
+		}
+	})
+	if initErr != nil {
+		return initErr
+	}
+
+	if err := rdt.SetConfigFromFile(configFilePath, true); err != nil {
+		return err
+	}
+	enabled = true
+	return nil
+}
+
+// ContainerClassFromAnnotations examines container and pod annotations of a
+// container and returns its RDT class.
+func ContainerClassFromAnnotations(containerName string, containerAnnotations, podAnnotations map[string]string) (string, error) {
+	return rdt.ContainerClassFromAnnotations(containerName, containerAnnotations, podAnnotations)
+}