近期有一需求：前端页面点击执行任务，实时显示后端执行情况，思考一波；发现 WebSocket 最适合做这件事。
效果
测试 ping www.baidu.com 效果
点击连接建立ws连接
后端实现
所需软件包
后端主要借助Django Channels 实现socket连接，官网文档链接
这里想实现每个连接进来加入组进行广播，所以还需要引入 channels-redis 。
pip
channels==2.2.0 channels-redis==2.4.0
引入
settings.py
INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'rest_framework.authtoken',
'rest_framework',
...
'channels',
]
# Redis配置
REDIS_HOST = ENV_DICT.get('REDIS_HOST', '127.0.0.1')
REDIS_PORT = ENV_DICT.get('REDIS_PORT', 6379)
CHANNEL_LAYERS = {
"default": {
"BACKEND": "channels_redis.core.RedisChannelLayer",
"CONFIG": {
"hosts": [(REDIS_HOST, REDIS_PORT)],
},
},
}
代码
apps/consumers.py
新建一个消费处理
实现： 默认连接加入组，发送信息时的处理。
from channels.generic.websocket import WebsocketConsumer
class MyConsumer(WebsocketConsumer):
def connect(self):
"""
每个任务作为一个频道
默认进入对应任务执行频道
"""
self.job_name = self.scope['url_route']['kwargs']['job_name']
self.job_group_name = 'job_%s' % self.job_name
async_to_sync(self.channel_layer.group_add)(
self.job_group_name,
self.channel_name
)
self.accept()
def disconnect(self, close_code):
async_to_sync(self.channel_layer.group_discard)(
self.job_group_name,
self.channel_name
)
# job.message类型处理
def job_message(self, event):
# 默认发送收到信息
self.send(text_data=event["text"])
apps/routing.py
ws类型路由
实现：ws/job/<job_name>由 MyConsumer 去处理。
from . import consumers
from django.urls import path
from channels.routing import ProtocolTypeRouter, URLRouter
from channels.sessions import SessionMiddlewareStack
application = ProtocolTypeRouter({
'websocket': SessionMiddlewareStack(
URLRouter(
[
path('ws/job/<str:job_name>', consumers.MyConsumer)
]
)
),
})
apps/views.py
在执行命令中获取 webSocket 消费通道，进行异步推送
- 使用异步推送async_to_sync是因为在连接的时候采用的异步连接，所以推送必须采用异步推送。
- 因为执行任务时间过长，启动触发运行时加入多线程，直接先返回ok，后端运行任务。
from subprocess import Popen,PIPE
import threading
def runPopen(job):
"""
执行命令,返回popen
"""
path = os.path
Path = path.abspath(path.join(BASE_DIR, path.pardir))
script_path = path.abspath(path.join(Path,'run.sh'))
cmd = "sh %s %s" % (script_path, job)
return Popen(cmd, shell=True, stdout=PIPE, stderr=PIPE)
def runScript(job):
channel_layer = get_channel_layer()
group_name = "job_%s" % job
popen = runPopen(job)
while True:
output = popen.stdout.readline()
if output == '' and popen.poll() is not None:
break
if output:
output_text = str(output.strip())
async_to_sync(
channel_layer.group_send
)(
group_name,
{"type": "job.message", "text": output_text}
)
else:
err = popen.stderr.readline()
err_text = str(err.strip())
async_to_sync(
channel_layer.group_send
)(
group_name,
{"type": "job.message", "text": err_text}
)
break
class StartJob(APIView):
def get(self, request, job=None):
run = threading.Thread(target=runScript, args=(job,))
run.start()
return HttpResponse('ok')
apps/urls.py
get请求就能启动任务
urlpatterns = [
...
path('start_job/<str:job>', StartJob.as_view())
]
前端实现
所需软件包
vue-native-websocket
代码实现
plugins/vueNativeWebsocket.js
import Vue from 'vue'
import VueNativeSock from '../utils/socket/Main.js'
export default function ({ store }) {
Vue.use(VueNativeSock, 'http://localhost:8000/ws/job', {connectManually: true,});
}
nuxt.config.js
配置文件引入， 这里我使用的是 nuxt 框架
plugins: [
{
src: '@/plugins/vueNativeWebsocket.js',
***: false
},
],
封装 socket
export default (connection_url, option) => {
// 事件
let event = ['message', 'close', 'error', 'open'];
// 拷贝选项字典
let opts = Object.assign({}, option);
// 定义实例字典
let instance = {
// socket实例
socket: '',
// 是否连接状态
is_conncet: false,
// 具体连接方法
connect: function() {
if(connection_url) {
let scheme = window.location.protocol === 'https:' "htmlcode">
<template>
<div>
<el-button type="primary" @click="runFunction" >执行</el-button>
<el-button type="primary" @click="connectWebSock" >显示</el-button>
<div class="socketView">
<span v-for="i in socketMessage" :key="i">{{i}}</span>
</div>
</div>
</template>
<script>
import R from '@/plugins/axios';
import ws from '@/plugins/socket'
export default {
data() {
return {
webSocket: '',
socketMessage: [],
}
},
methods: {
// 打开连接的处理
openSocket(e) {
if (e.isTrusted) {
const h = this.$createElement;
this.$notify({
title: '提示',
message: h('i', { style: 'color: teal'}, '已建立Socket连接')
});
}
},
// 连接时的处理
listenSocket(e) {
if (e.data){
this.socketMessage.push(this.x2Str(e.data))
}
},
// 连接webSocket
connectWebSock() {
let wsuri = process.env.BACKEND_URL + '/ws/job/' + this.selectFunctions
this.webSocket = ws(wsuri, {
open: e => this.openSocket(e),
message: e => this.listenSocket(e),
close: e => this.closeSocket(e)
})
},
// 转码
x2Str(str) {
if (str) {
let reg = new RegExp("(")
let result = str.replace(/(?:\\x[\da-fA-F]{2})+/g, m =>
decodeURIComponent(m.replace(/\\x/g, '%'))
)
return reg.exec(result)[0]
}
},
// 执行方法
runFunction() {
R.myRequest('GET','api/start_job/' + this.selectFunctions, {}, {}).then((response) => {
if (response.hasOwnProperty('response')){
this.$message({
type: 'error',
message: '服务端返回错误,返回码:' + response.response.status
});
};
if (response.data == 'ok') {
this.$message({
type: 'success',
message: '开始执行[' + this.selectFunctions + ']'
});
}
});
}
}
}
</script>
至此，实现前后端 websocket 通讯。
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。