kerbernets 中CPU 亲和性实现

kerbernets 中CPU亲和性是1.8中的alpha 特性.这个特性主要功能是可以控制启动容器在cpu核数控制和具体运行在哪个核上。

这个特性主要修改的代码在pkg/kubelet/cm 中。

首先在cmd/kubelet/app/server.go中启动容器管理器ContainerManager。

kubeDeps.ContainerManager, err = cm.NewContainerManager(

而在启动容器管理器时候。初始CPU管理器cpumanager。

pkg/kubelet/cm/container_manager_linux.go:197:func NewContainerManager(mountUtil mount.Interface, cadvisorInter// Initialize CPU managerif utilfeature.DefaultFeatureGate.Enabled(kubefeatures.CPUManager) {cm.cpuManager, err = cpumanager.NewManager(nodeConfig.ExperimentalCPUManagerPolicy,nodeConfig.ExperimentalCPUManagerReconcilePeriod,machineInfo,cm.GetNodeAllocatableReservation(),nodeConfig.KubeletRootDir,)if err != nil {glog.Errorf("failed to initialize cpu manager: %v", err)return nil, err}}

当kubelet启动或者销毁容器前，容器生命周期实现都会调用CPU管理器来管理CPU相关特性。

pkg/kubelet/cm/internal_container_lifecycle.gofunc (i *internalContainerLifecycleImpl) PreStartContainer(pod *v1.Pod, container *v1.Container, containerID string) error {if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.CPUManager) {return i.cpuManager.AddContainer(pod, container, containerID)}return nil}func (i *internalContainerLifecycleImpl) PreStopContainer(containerID string) error {if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.CPUManager) {return i.cpuManager.RemoveContainer(containerID)}return nil}func (i *internalContainerLifecycleImpl) PostStopContainer(containerID string) error {if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.CPUManager) {return i.cpuManager.RemoveContainer(containerID)}return nil}

其中添加容器到CPU管理器

err = m.updateContainerCPUSet(containerID, cpus)m.containerRuntime.UpdateContainerResources(containerID,&runtimeapi.LinuxContainerResources{CpusetCpus: cpus.String(),})}

调用docker 客户端修改容器资源

pkg/kubelet/dockershim/docker_container.gofunc (ds *dockerService) UpdateContainerResources(containerID string, resources *runtimeapi.LinuxContainerResources) error {updateConfig := dockercontainer.UpdateConfig{Resources: dockercontainer.Resources{CPUPeriod:  resources.CpuPeriod,CPUQuota:   resources.CpuQuota,CPUShares:  resources.CpuShares,Memory:     resources.MemoryLimitInBytes,CpusetCpus: resources.CpusetCpus,CpusetMems: resources.CpusetMems,},}err := ds.client.UpdateContainerResources(containerID, updateConfig)//最终调用docker API post更新数据if err != nil {return fmt.Errorf("failed to update container %q: %v", containerID, err)}return nil}