github.com/april1989/origin-go-tools@v0.0.32/cmd/present/main.go (about)

     1  // Copyright 2013 The Go Authors.  All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package main
     6  
     7  import (
     8  	"flag"
     9  	"fmt"
    10  	"go/build"
    11  	"log"
    12  	"net"
    13  	"net/http"
    14  	"net/url"
    15  	"os"
    16  	"strings"
    17  
    18  	"github.com/april1989/origin-go-tools/present"
    19  )
    20  
    21  const basePkg = "github.com/april1989/origin-go-tools/cmd/present"
    22  
    23  var (
    24  	httpAddr      = flag.String("http", "127.0.0.1:3999", "HTTP service address (e.g., '127.0.0.1:3999')")
    25  	originHost    = flag.String("orighost", "", "host component of web origin URL (e.g., 'localhost')")
    26  	basePath      = flag.String("base", "", "base path for slide template and static resources")
    27  	contentPath   = flag.String("content", ".", "base path for presentation content")
    28  	usePlayground = flag.Bool("use_playground", false, "run code snippets using play.golang.org; if false, run them locally and deliver results by WebSocket transport")
    29  	nativeClient  = flag.Bool("nacl", false, "use Native Client environment playground (prevents non-Go code execution) when using local WebSocket transport")
    30  )
    31  
    32  func main() {
    33  	flag.BoolVar(&present.PlayEnabled, "play", true, "enable playground (permit execution of arbitrary user code)")
    34  	flag.BoolVar(&present.NotesEnabled, "notes", false, "enable presenter notes (press 'N' from the browser to display them)")
    35  	flag.Parse()
    36  
    37  	if os.Getenv("GAE_ENV") == "standard" {
    38  		log.Print("Configuring for App Engine Standard")
    39  		port := os.Getenv("PORT")
    40  		if port == "" {
    41  			port = "8080"
    42  		}
    43  		*httpAddr = fmt.Sprintf("0.0.0.0:%s", port)
    44  		pwd, err := os.Getwd()
    45  		if err != nil {
    46  			log.Fatalf("Couldn't get pwd: %v\n", err)
    47  		}
    48  		*basePath = pwd
    49  		*usePlayground = true
    50  		*contentPath = "./content/"
    51  	}
    52  
    53  	if *basePath == "" {
    54  		p, err := build.Default.Import(basePkg, "", build.FindOnly)
    55  		if err != nil {
    56  			fmt.Fprintf(os.Stderr, "Couldn't find gopresent files: %v\n", err)
    57  			fmt.Fprintf(os.Stderr, basePathMessage, basePkg)
    58  			os.Exit(1)
    59  		}
    60  		*basePath = p.Dir
    61  	}
    62  	err := initTemplates(*basePath)
    63  	if err != nil {
    64  		log.Fatalf("Failed to parse templates: %v", err)
    65  	}
    66  
    67  	ln, err := net.Listen("tcp", *httpAddr)
    68  	if err != nil {
    69  		log.Fatal(err)
    70  	}
    71  	defer ln.Close()
    72  
    73  	_, port, err := net.SplitHostPort(ln.Addr().String())
    74  	if err != nil {
    75  		log.Fatal(err)
    76  	}
    77  
    78  	origin := &url.URL{Scheme: "http"}
    79  	if *originHost != "" {
    80  		if strings.HasPrefix(*originHost, "https://") {
    81  			*originHost = strings.TrimPrefix(*originHost, "https://")
    82  			origin.Scheme = "https"
    83  		}
    84  		*originHost = strings.TrimPrefix(*originHost, "http://")
    85  		origin.Host = net.JoinHostPort(*originHost, port)
    86  	} else if ln.Addr().(*net.TCPAddr).IP.IsUnspecified() {
    87  		name, _ := os.Hostname()
    88  		origin.Host = net.JoinHostPort(name, port)
    89  	} else {
    90  		reqHost, reqPort, err := net.SplitHostPort(*httpAddr)
    91  		if err != nil {
    92  			log.Fatal(err)
    93  		}
    94  		if reqPort == "0" {
    95  			origin.Host = net.JoinHostPort(reqHost, port)
    96  		} else {
    97  			origin.Host = *httpAddr
    98  		}
    99  	}
   100  
   101  	initPlayground(*basePath, origin)
   102  	http.Handle("/static/", http.FileServer(http.Dir(*basePath)))
   103  
   104  	if !ln.Addr().(*net.TCPAddr).IP.IsLoopback() &&
   105  		present.PlayEnabled && !*nativeClient && !*usePlayground {
   106  		log.Print(localhostWarning)
   107  	}
   108  
   109  	log.Printf("Open your web browser and visit %s", origin.String())
   110  	if present.NotesEnabled {
   111  		log.Println("Notes are enabled, press 'N' from the browser to display them.")
   112  	}
   113  	log.Fatal(http.Serve(ln, nil))
   114  }
   115  
   116  func environ(vars ...string) []string {
   117  	env := os.Environ()
   118  	for _, r := range vars {
   119  		k := strings.SplitAfter(r, "=")[0]
   120  		var found bool
   121  		for i, v := range env {
   122  			if strings.HasPrefix(v, k) {
   123  				env[i] = r
   124  				found = true
   125  			}
   126  		}
   127  		if !found {
   128  			env = append(env, r)
   129  		}
   130  	}
   131  	return env
   132  }
   133  
   134  const basePathMessage = `
   135  By default, gopresent locates the slide template files and associated
   136  static content by looking for a %q package
   137  in your Go workspaces (GOPATH).
   138  
   139  You may use the -base flag to specify an alternate location.
   140  `
   141  
   142  const localhostWarning = `
   143  WARNING!  WARNING!  WARNING!
   144  
   145  The present server appears to be listening on an address that is not localhost
   146  and is configured to run code snippets locally. Anyone with access to this address
   147  and port will have access to this machine as the user running present.
   148  
   149  To avoid this message, listen on localhost, run with -play=false, or run with
   150  -play_socket=false.
   151  
   152  If you don't understand this message, hit Control-C to terminate this process.
   153  
   154  WARNING!  WARNING!  WARNING!
   155  `