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			123 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			123 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| /*
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| Copyright 2015 The Kubernetes Authors All rights reserved.
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| 
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| Licensed under the Apache License, Version 2.0 (the "License");
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| you may not use this file except in compliance with the License.
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| You may obtain a copy of the License at
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| 
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|     http://www.apache.org/licenses/LICENSE-2.0
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| 
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| Unless required by applicable law or agreed to in writing, software
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| distributed under the License is distributed on an "AS IS" BASIS,
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| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| See the License for the specific language governing permissions and
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| limitations under the License.
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| */
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| 
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| // A tiny web server for viewing the environment kubernetes creates for your
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| // containers. It exposes the filesystem and environment variables via http
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| // server.
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| package main
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| 
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| import (
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| 	"flag"
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| 	"fmt"
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| 	"log"
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| 	"net"
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| 	"net/http"
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| 	"os"
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| 
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| 	"github.com/davecgh/go-spew/spew"
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| )
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| 
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| var (
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| 	port = flag.Int("port", 8080, "Port number to serve at.")
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| )
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| 
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| func main() {
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| 	flag.Parse()
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| 	hostname, err := os.Hostname()
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| 	if err != nil {
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| 		log.Fatalf("Error getting hostname: %v", err)
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| 	}
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| 
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| 	links := []struct {
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| 		link, desc string
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| 	}{
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| 		{"/fs/", "Complete file system as seen by this container."},
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| 		{"/vars/", "Environment variables as seen by this container."},
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| 		{"/hostname/", "Hostname as seen by this container."},
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| 		{"/dns?q=google.com", "Explore DNS records seen by this container."},
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| 		{"/quit", "Cause this container to exit."},
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| 	}
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| 
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| 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
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| 		fmt.Fprintf(w, "<b> Kubernetes environment explorer </b><br/><br/>")
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| 		for _, v := range links {
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| 			fmt.Fprintf(w, `<a href="%v">%v: %v</a><br/>`, v.link, v.link, v.desc)
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| 		}
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| 	})
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| 
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| 	http.Handle("/fs/", http.StripPrefix("/fs/", http.FileServer(http.Dir("/"))))
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| 	http.HandleFunc("/vars/", func(w http.ResponseWriter, r *http.Request) {
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| 		for _, v := range os.Environ() {
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| 			fmt.Fprintf(w, "%v\n", v)
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| 		}
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| 	})
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| 	http.HandleFunc("/hostname/", func(w http.ResponseWriter, r *http.Request) {
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| 		fmt.Fprintf(w, hostname)
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| 	})
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| 	http.HandleFunc("/quit", func(w http.ResponseWriter, r *http.Request) {
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| 		os.Exit(0)
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| 	})
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| 	http.HandleFunc("/dns", dns)
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| 
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| 	go log.Fatal(http.ListenAndServe(fmt.Sprintf("0.0.0.0:%d", *port), nil))
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| 
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| 	select {}
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| }
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| 
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| func dns(w http.ResponseWriter, r *http.Request) {
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| 	q := r.URL.Query().Get("q")
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| 	// Note that the below is NOT safe from input attacks, but that's OK
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| 	// because this is just for debugging.
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| 	fmt.Fprintf(w, `<html><body>
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| <form action="/dns">
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| <input name="q" type="text" value="%v"></input>
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| <button type="submit">Lookup</button>
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| </form>
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| <br/><br/><pre>`, q)
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| 	{
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| 		res, err := net.LookupNS(q)
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| 		spew.Fprintf(w, "LookupNS(%v):\nResult: %#v\nError: %v\n\n", q, res, err)
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| 	}
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| 	{
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| 		res, err := net.LookupTXT(q)
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| 		spew.Fprintf(w, "LookupTXT(%v):\nResult: %#v\nError: %v\n\n", q, res, err)
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| 	}
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| 	{
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| 		cname, res, err := net.LookupSRV("", "", q)
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| 		spew.Fprintf(w, `LookupSRV("", "", %v):
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| cname: %v
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| Result: %#v
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| Error: %v
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| 
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| `, q, cname, res, err)
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| 	}
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| 	{
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| 		res, err := net.LookupHost(q)
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| 		spew.Fprintf(w, "LookupHost(%v):\nResult: %#v\nError: %v\n\n", q, res, err)
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| 	}
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| 	{
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| 		res, err := net.LookupIP(q)
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| 		spew.Fprintf(w, "LookupIP(%v):\nResult: %#v\nError: %v\n\n", q, res, err)
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| 	}
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| 	{
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| 		res, err := net.LookupMX(q)
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| 		spew.Fprintf(w, "LookupMX(%v):\nResult: %#v\nError: %v\n\n", q, res, err)
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| 	}
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| 	fmt.Fprintf(w, `</pre>
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| </body>
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| </html>`)
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| }
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