Merge pull request #13982 from ArtfulCoder/netexec

contrib/for-tests/netexec/.gitignore

+netexec

contrib/for-tests/netexec/Dockerfile

+FROM busybox
+MAINTAINER Abhishek Shah "abshah@google.com"
+
+ADD netexec netexec
+ADD netexec.go netexec.go
+
+ENTRYPOINT ["/netexec"]

contrib/for-tests/netexec/Makefile

+.PHONY: all netexec image push clean
+
+TAG = 1.0
+PREFIX = gcr.io/google_containers
+
+all: push
+
+TAG = 1.0
+
+netexec: netexec.go
+	CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -ldflags '-w' ./netexec.go
+
+image: netexec
+	docker build -t $(PREFIX)/netexec:$(TAG) .
+
+push: image
+	gcloud docker push $(PREFIX)/netexec:$(TAG)
+
+clean:
+	rm -f netexec

contrib/for-tests/netexec/netexec.go

+/*
+Copyright 2014 The Kubernetes Authors All rights reserved.
+
+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 main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net"
+	"net/http"
+	"net/url"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+	"time"
+)
+
+var (
+	httpPort  = 8080
+	udpPort   = 8081
+	shellPath = "/bin/sh"
+)
+
+type output struct {
+	responses []string
+	errors    []string
+}
+
+func init() {
+	flag.IntVar(&httpPort, "http-port", 8080, "HTTP Listen Port")
+	flag.IntVar(&udpPort, "udp-port", 8081, "UDP Listen Port")
+}
+
+func main() {
+	flag.Parse()
+	go startUDPServer(udpPort)
+	startHTTPServer(httpPort)
+}
+
+func startHTTPServer(httpPort int) {
+	http.HandleFunc("/shutdown", shutdownHandler)
+	http.HandleFunc("/hostName", hostNameHandler)
+	http.HandleFunc("/shell", shellHandler)
+	http.HandleFunc("/dial", dialHandler)
+	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%d", httpPort), nil))
+}
+
+func shutdownHandler(w http.ResponseWriter, r *http.Request) {
+	os.Exit(0)
+}
+
+func dialHandler(w http.ResponseWriter, r *http.Request) {
+	values, err := url.Parse(r.URL.RequestURI())
+	if err != nil {
+		http.Error(w, fmt.Sprintf("%v", err), http.StatusBadRequest)
+		return
+	}
+
+	host := values.Query().Get("host")
+	port := values.Query().Get("port")
+	request := values.Query().Get("request") // hostName
+	protocol := values.Query().Get("protocol")
+	tryParam := values.Query().Get("tries")
+	tries := 1
+	if len(tryParam) > 0 {
+		tries, err = strconv.Atoi(tryParam)
+	}
+	if err != nil {
+		http.Error(w, fmt.Sprintf("tries parameter is invalid. %v", err), http.StatusBadRequest)
+		return
+	}
+	if len(request) == 0 {
+		http.Error(w, fmt.Sprintf("request parameter not specified. %v", err), http.StatusBadRequest)
+		return
+	}
+	if len(protocol) == 0 {
+		protocol = "http"
+	} else {
+		protocol = strings.ToLower(protocol)
+	}
+	if protocol != "http" && protocol != "udp" {
+		http.Error(w, fmt.Sprintf("unsupported protocol. %s", protocol), http.StatusBadRequest)
+		return
+	}
+
+	hostPort := net.JoinHostPort(host, port)
+	var udpAddress *net.UDPAddr
+	if protocol == "udp" {
+		udpAddress, err = net.ResolveUDPAddr("udp", hostPort)
+		if err != nil {
+			http.Error(w, fmt.Sprintf("host and/or port param are invalid. %v", err), http.StatusBadRequest)
+			return
+		}
+	} else {
+		_, err = net.ResolveTCPAddr("tcp", hostPort)
+		if err != nil {
+			http.Error(w, fmt.Sprintf("host and/or port param are invalid. %v", err), http.StatusBadRequest)
+			return
+		}
+	}
+	errors := make([]string, 0)
+	responses := make([]string, 0)
+	var response string
+	for i := 0; i < tries; i++ {
+		if protocol == "udp" {
+			response, err = dialUDP(request, udpAddress)
+		} else {
+			response, err = dialHTTP(request, hostPort)
+		}
+		if err != nil {
+			errors = append(errors, fmt.Sprintf("%v", err))
+		} else {
+			responses = append(responses, response)
+		}
+	}
+	output := map[string][]string{}
+	if len(response) > 0 {
+		output["responses"] = responses
+	}
+	if len(errors) > 0 {
+		output["errors"] = errors
+	}
+	bytes, err := json.Marshal(output)
+	if err == nil {
+		fmt.Fprintf(w, string(bytes))
+	} else {
+		http.Error(w, fmt.Sprintf("response could not be serialized. %v", err), http.StatusExpectationFailed)
+	}
+}
+
+func dialHTTP(request, hostPort string) (string, error) {
+	transport := &http.Transport{}
+	httpClient := createHTTPClient(transport)
+	resp, err := httpClient.Get(fmt.Sprintf("http://%s/%s", hostPort, request))
+	defer transport.CloseIdleConnections()
+	if err == nil {
+		defer resp.Body.Close()
+		body, err := ioutil.ReadAll(resp.Body)
+		if err == nil {
+			return string(body), nil
+		}
+	}
+	return "", err
+}
+
+func createHTTPClient(transport *http.Transport) *http.Client {
+	client := &http.Client{
+		Transport: transport,
+		Timeout:   5 * time.Second,
+	}
+	return client
+}
+
+func dialUDP(request string, remoteAddress *net.UDPAddr) (string, error) {
+	Conn, err := net.DialUDP("udp", nil, remoteAddress)
+	if err != nil {
+		return "", fmt.Errorf("udp dial failed. err:%v", err)
+	}
+
+	defer Conn.Close()
+	buf := []byte(request)
+	_, err = Conn.Write(buf)
+	if err != nil {
+		return "", fmt.Errorf("udp connection write failed. err:%v", err)
+	}
+	udpResponse := make([]byte, 1024)
+	Conn.SetReadDeadline(time.Now().Add(5 * time.Second))
+	count, err := Conn.Read(udpResponse)
+	if err != nil || count == 0 {
+		return "", fmt.Errorf("reading from udp connection failed. err:'%v'", err)
+	}
+	return string(udpResponse[0:count]), nil
+}
+
+func shellHandler(w http.ResponseWriter, r *http.Request) {
+	log.Println(r.FormValue("shellCommand"))
+	output, err := exec.Command(shellPath, "-c", r.FormValue("shellCommand")).CombinedOutput()
+	assertNoError(err)
+	fmt.Fprintf(w, string(output))
+}
+
+func hostNameHandler(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintf(w, getHostName())
+}
+
+// udp server only supports the hostName command.
+func startUDPServer(udpPort int) {
+	serverAddress, err := net.ResolveUDPAddr("udp", fmt.Sprintf(":%d", udpPort))
+	assertNoError(err)
+	serverConn, err := net.ListenUDP("udp", serverAddress)
+	defer serverConn.Close()
+	buf := make([]byte, 1024)
+
+	for {
+		n, clientAddress, err := serverConn.ReadFromUDP(buf)
+		assertNoError(err)
+		receivedText := strings.TrimSpace(string(buf[0:n]))
+		if receivedText == "hostName" {
+			log.Println("Sending udp hostName response")
+			_, err = serverConn.WriteToUDP([]byte(getHostName()), clientAddress)
+			assertNoError(err)
+		} else if len(receivedText) > 0 {
+			log.Println("Unknown udp command received. ", receivedText)
+		}
+	}
+}
+
+func getHostName() string {
+	hostName, err := os.Hostname()
+	assertNoError(err)
+	return hostName
+}
+
+func assertNoError(err error) {
+	if err != nil {
+		log.Fatal("Error occurred. error:", err)
+	}
+}

hack/verify-flags/known-flags.txt

@@ -272,6 +272,7 @@ tls-private-key-file
 token-auth-file
 ttl-secs
 type-src
+udp-port
 unix-socket
 update-period
 upgrade-target