find-runtime.go

// 根据宿主机目录中的文件找到具体容器运行时
detectRuntime("/var/run")

func detectRuntime(varRunPath string) []runtimeConfig {
	var err error
	var cfgs []runtimeConfig

	// pouch
	{
		_, err1 := os.Stat(fmt.Sprintf("%s/pouchd.sock", varRunPath))
		_, err2 := os.Stat(fmt.Sprintf("%s/pouchcri.sock", varRunPath))
		if err1 == nil && err2 == nil {
			cfgs = append(cfgs, runtimeConfig{
				runtimeType:      ContainerRuntimePouch,
				runtimeURI:       fmt.Sprintf("unix://%s/pouchd.sock", varRunPath),
				runtimeRemoteURI: fmt.Sprintf("unix://%s/pouchcri.sock", varRunPath),
			})
		} else if err1 == nil && err2 != nil {
			klog.Errorf("%s/pouchd.sock exists, but not found %s/pouchcri.sock", varRunPath, varRunPath)
		} else if err1 != nil && err2 == nil {
			klog.Errorf("%s/pouchdcri.sock exists, but not found %s/pouchd.sock", varRunPath, varRunPath)
		}
	}

	// docker
	{
		_, err1 := os.Stat(fmt.Sprintf("%s/docker.sock", varRunPath))
		_, err2 := os.Stat(fmt.Sprintf("%s/dockershim.sock", varRunPath))
		if err1 == nil && err2 == nil {
			cfgs = append(cfgs, runtimeConfig{
				runtimeType:      ContainerRuntimeDocker,
				runtimeURI:       fmt.Sprintf("unix://%s/docker.sock", varRunPath),
				runtimeRemoteURI: fmt.Sprintf("unix://%s/dockershim.sock", varRunPath),
			})
		} else if err1 == nil && err2 != nil {
			klog.Errorf("%s/docker.sock exists, but not found %s/dockershim.sock", varRunPath, varRunPath)
		} else if err1 != nil && err2 == nil {
			klog.Errorf("%s/dockershim.sock exists, but not found %s/docker.sock", varRunPath, varRunPath)
		}
	}

	// containerd
	{
		if _, err = os.Stat(fmt.Sprintf("%s/containerd.sock", varRunPath)); err == nil {
			cfgs = append(cfgs, runtimeConfig{
				runtimeType:      ContainerRuntimeContainerd,
				runtimeRemoteURI: fmt.Sprintf("unix://%s/containerd.sock", varRunPath),
			})
		}
		if _, err = os.Stat(fmt.Sprintf("%s/containerd/containerd.sock", varRunPath)); err == nil {
			cfgs = append(cfgs, runtimeConfig{
				runtimeType:      ContainerRuntimeContainerd,
				runtimeRemoteURI: fmt.Sprintf("unix://%s/containerd/containerd.sock", varRunPath),
			})
		}
	}

	return cfgs
}

复制自
https://github.com/openkruise/kruise/blob/master/pkg/daemon/criruntime/factory.go
，值得注意的是，openshift平台（版本 4.7.11）， /var/run 目录下面只有

1. docker.sock
2. gssproxy.sock
3. rpcbind.sock
   运行这个方法，会得到一个空数组。