Kubelet: generate sandbox/container config for new runtime API

pkg/kubelet/kuberuntime/helpers.go

@@ -0,0 +1,160 @@
+/*
+Copyright 2016 The Kubernetes 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 kuberuntime
+
+import (
+	"fmt"
+	"math/rand"
+	"strconv"
+	"strings"
+
+	"github.com/golang/glog"
+	"k8s.io/kubernetes/pkg/api"
+	runtimeApi "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
+	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
+)
+
+const (
+	// kubePrefix is used to identify the containers/sandboxes on the node managed by kubelet
+	kubePrefix = "k8s"
+	// kubeSandboxNamePrefix is used to keep sandbox name consistent with old podInfraContainer name
+	kubeSandboxNamePrefix = "POD"
+
+	// Taken from lmctfy https://github.com/google/lmctfy/blob/master/lmctfy/controllers/cpu_controller.cc
+	minShares     = 2
+	sharesPerCPU  = 1024
+	milliCPUToCPU = 1000
+
+	// 100000 is equivalent to 100ms
+	quotaPeriod    = 100000
+	minQuotaPeriod = 1000
+)
+
+// buildSandboxName creates a name which can be reversed to identify sandbox full name
+func buildSandboxName(pod *api.Pod) string {
+	_, sandboxName, _ := buildKubeGenericName(pod, kubeSandboxNamePrefix)
+	return sandboxName
+}
+
+// parseSandboxName unpacks a sandbox full name, returning the pod name, namespace and uid
+func parseSandboxName(name string) (string, string, string, error) {
+	podName, podNamespace, podUID, _, _, err := parseContainerName(name)
+	if err != nil {
+		return "", "", "", err
+	}
+
+	return podName, podNamespace, podUID, nil
+}
+
+// buildContainerName creates a name which can be reversed to identify container name.
+// This function returns stable name, unique name and an unique id.
+func buildContainerName(pod *api.Pod, container *api.Container) (string, string, string) {
+	// kubelet uses hash to determine whether an existing container matches the desired spec.
+	containerName := container.Name + "." + strconv.FormatUint(kubecontainer.HashContainer(container), 16)
+	return buildKubeGenericName(pod, containerName)
+}
+
+// buildKubeGenericName creates a name which can be reversed to identify container/sandbox name.
+// This function returns stable name, unique name and an unique id.
+func buildKubeGenericName(pod *api.Pod, containerName string) (string, string, string) {
+	stableName := fmt.Sprintf("%s_%s_%s_%s_%s",
+		kubePrefix,
+		containerName,
+		pod.Name,
+		pod.Namespace,
+		string(pod.UID),
+	)
+	UID := fmt.Sprintf("%08x", rand.Uint32())
+	return stableName, fmt.Sprintf("%s_%s", stableName, UID), UID
+}
+
+// parseContainerName unpacks a container name, returning the pod name, namespace, UID and container name
+func parseContainerName(name string) (podName, podNamespace, podUID, containerName string, hash uint64, err error) {
+	parts := strings.Split(name, "_")
+	if len(parts) == 0 || parts[0] != kubePrefix {
+		err = fmt.Errorf("failed to parse container name %q into parts", name)
+		return "", "", "", "", 0, err
+	}
+	if len(parts) < 6 {
+		glog.Warningf("Found a container with the %q prefix, but too few fields (%d): %q", kubePrefix, len(parts), name)
+		err = fmt.Errorf("container name %q has fewer parts than expected %v", name, parts)
+		return "", "", "", "", 0, err
+	}
+
+	nameParts := strings.Split(parts[1], ".")
+	containerName = nameParts[0]
+	if len(nameParts) > 1 {
+		hash, err = strconv.ParseUint(nameParts[1], 16, 32)
+		if err != nil {
+			glog.Warningf("Invalid container hash %q in container %q", nameParts[1], name)
+		}
+	}
+
+	return parts[2], parts[3], parts[4], containerName, hash, nil
+}
+
+// toRuntimeProtocol converts api.Protocol to runtimeApi.Protocol
+func toRuntimeProtocol(protocol api.Protocol) runtimeApi.Protocol {
+	switch protocol {
+	case api.ProtocolTCP:
+		return runtimeApi.Protocol_TCP
+	case api.ProtocolUDP:
+		return runtimeApi.Protocol_UDP
+	}
+
+	glog.Warningf("Unknown protocol %q: defaulting to TCP", protocol)
+	return runtimeApi.Protocol_TCP
+}
+
+// milliCPUToShares converts milliCPU to CPU shares
+func milliCPUToShares(milliCPU int64) int64 {
+	if milliCPU == 0 {
+		// Return 2 here to really match kernel default for zero milliCPU.
+		return minShares
+	}
+	// Conceptually (milliCPU / milliCPUToCPU) * sharesPerCPU, but factored to improve rounding.
+	shares := (milliCPU * sharesPerCPU) / milliCPUToCPU
+	if shares < minShares {
+		return minShares
+	}
+	return shares
+}
+
+// milliCPUToQuota converts milliCPU to CFS quota and period values
+func milliCPUToQuota(milliCPU int64) (quota int64, period int64) {
+	// CFS quota is measured in two values:
+	//  - cfs_period_us=100ms (the amount of time to measure usage across)
+	//  - cfs_quota=20ms (the amount of cpu time allowed to be used across a period)
+	// so in the above example, you are limited to 20% of a single CPU
+	// for multi-cpu environments, you just scale equivalent amounts
+	if milliCPU == 0 {
+		return
+	}
+
+	// we set the period to 100ms by default
+	period = quotaPeriod
+
+	// we then convert your milliCPU to a value normalized over a period
+	quota = (milliCPU * quotaPeriod) / milliCPUToCPU
+
+	// quota needs to be a minimum of 1ms.
+	if quota < minQuotaPeriod {
+		quota = minQuotaPeriod
+	}
+
+	return
+}