hyper.go

//A simplest case to call a independently running remote container runtime (e.g. sever.go).
func (r *runtime) GetContainerLogs(pod *api.Pod, containerID kubecontainer.ContainerID, logOptions *api.PodLogOptions, stdout, stderr io.Writer) error {
	args := &Args{Pod: pod, ContainerID: containerID, LogOptions: logOptions}

	url := "http://localhost:1234/logs"

	message, err := json.Marshal(args)
	if err != nil {
		log.Fatalf("Fail to marshal args %v", err)
	}
	req, err := http.NewRequest("POST", url, bytes.NewBuffer(message))
	if err != nil {
		log.Fatalf("%s", err)
	}
	req.Header.Set("Content-Type", "application/json")
	client := new(http.Client)
	resp, err := client.Do(req)
	if err != nil {
		log.Fatalf("Error in sending request to %s. %s", url, err)
	}
	defer resp.Body.Close()

	if stdout != nil {
		io.Copy(stdout, resp.Body)
	}

	return nil
}

server.go

// server.go
package main

import (
	"encoding/json"
	"log"
	"net/http"
	"os"

	"github.com/gorilla/mux"

	"k8s.io/kubernetes/pkg/api"
	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
	"k8s.io/kubernetes/pkg/kubelet/hyper"
)

type Args struct {
	Pod         *api.Pod
	ContainerID kubecontainer.ContainerID
	LogOptions  *api.PodLogOptions
}

// A simplest http server to serve GetContainerLogs request.
func main() {
	router := mux.NewRouter()
	router.HandleFunc("/logs", HandleContainerLogs).Methods("POST")
	http.ListenAndServe(":1234", router)

}

func HandleContainerLogs(res http.ResponseWriter, req *http.Request) {
	var args Args

	decoder := json.NewDecoder(req.Body)
	err := decoder.Decode(&args)
	if err != nil {
		log.Fatal("Fail to decode request body: %v", err)
	}

	containerID := args.ContainerID
	logOptions := args.LogOptions

	hyperClient := hyper.NewHyperClient()
	var tailLines, since int64
	if logOptions.SinceSeconds != nil && *logOptions.SinceSeconds != 0 {
		since = *logOptions.SinceSeconds
	}
	if logOptions.TailLines != nil && *logOptions.TailLines != 0 {
		tailLines = *logOptions.TailLines
	}

	opts := hyper.ContainerLogsOptions{
		Container:    containerID.ID,
		OutputStream: res,
		ErrorStream:  os.Stderr,
		Follow:       logOptions.Follow,
		Timestamps:   logOptions.Timestamps,
		Since:        since,
		TailLines:    tailLines,
	}

	hyperClient.ContainerLogs(opts)

}