nanomsg.org/go/mangos/v2@v2.0.9-0.20200203084354-8a092611e461/examples/websocket/main.go (about)

     1  // Copyright 2016 The Mangos Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use file except in compliance with the License.
     5  // You may obtain a copy of the license at
     6  //
     7  //    http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // websocket implements a simple websocket server for mangos, demonstrating
    16  // how to use multiplex multiple sockets on a single HTTP server instance.
    17  //
    18  // The server listens, and offers three paths:
    19  //
    20  //  - sub/    - SUB socket, publishes a message "PUB <count> <time>" each second
    21  //  - req/    - REQ socket, responds with a reply "REPLY <count> <time>"
    22  //  - static/ - static content, provided as ASCII "STATIC"
    23  //
    24  // To use:
    25  //
    26  //   $ go build .
    27  //   $ port=40899
    28  //   $ ./websocket server port & pid=$! && sleep 1
    29  //   $ ./websocket req $port
    30  //   $ ./websocket sub $port
    31  //   $ ./websocket static $port
    32  //   $ kill $pid
    33  //
    34  package main
    35  
    36  import (
    37  	"fmt"
    38  	"io/ioutil"
    39  	"net/http"
    40  	"os"
    41  	"strconv"
    42  )
    43  
    44  func die(format string, v ...interface{}) {
    45  	fmt.Fprintln(os.Stderr, fmt.Sprintf(format, v...))
    46  	os.Exit(1)
    47  }
    48  
    49  func usage() {
    50  	die("Usage: %s <server|req|sub|static> <port>\n", os.Args[0])
    51  }
    52  
    53  func main() {
    54  
    55  	if len(os.Args) != 3 {
    56  		usage()
    57  	}
    58  	port, e := strconv.Atoi(os.Args[2])
    59  	if e != nil || port < 0 || port > 65535 {
    60  		die("Invalid port number")
    61  	}
    62  	switch os.Args[1] {
    63  	case "server":
    64  		server(port)
    65  	case "req":
    66  		reqClient(port)
    67  	case "sub":
    68  		subClient(port)
    69  	case "static":
    70  		staticClient(port)
    71  	default:
    72  		usage()
    73  	}
    74  	os.Exit(0)
    75  }
    76  
    77  func server(port int) {
    78  	mux := http.NewServeMux()
    79  
    80  	addStaticHandler(mux)
    81  	addSubHandler(mux, port)
    82  	addReqHandler(mux, port)
    83  
    84  	e := http.ListenAndServe(fmt.Sprintf(":%d", port), mux)
    85  	die("Http server died: %v", e)
    86  }
    87  
    88  func staticClient(port int) {
    89  	url := fmt.Sprintf("http://127.0.0.1:%d/static", port)
    90  	resp, err := http.Get(url)
    91  	if err != nil {
    92  		die("Get failed: %v", err)
    93  	}
    94  	if resp.StatusCode != 200 {
    95  		die("Status code %d", resp.StatusCode)
    96  	}
    97  	body, _ := ioutil.ReadAll(resp.Body)
    98  	fmt.Printf("%s\n", string(body))
    99  	os.Exit(0)
   100  }