Node-RED使用指南：23:嵌入Node.js应用

青旅半醒 2023-07-13 05:58 6阅读 0赞

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Node-RED可以独立运行，也可以直接嵌入到Node.js应用中，这篇文章以具体的示例来进行说明。

# 环境说明 #

*  操作系统

liumiaocn:~ liumiao$ sw_vers
    ProductName:	Mac OS X
    ProductVersion:	10.15.2
    BuildVersion:	19C57
    liumiaocn:~ liumiao$

*  node版本

liumiaocn:~ liumiao$ node -v
    v10.15.3
    liumiaocn:~ liumiao$ npm -v
    6.4.1
    liumiaocn:~ liumiao$

*  Node-RED版本

liumiaocn:~ liumiao$ node-red -h
    Node-RED v1.0.4
    Usage: node-red [-v] [-?] [--settings settings.js] [--userDir DIR]
                    [--port PORT] [--title TITLE] [--safe] [flows.json]
    
    Options:
      -p, --port     PORT  port to listen on
      -s, --settings FILE  use specified settings file
          --title    TITLE process window title
      -u, --userDir  DIR   use specified user directory
      -v, --verbose        enable verbose output
          --safe           enable safe mode
      -?, --help           show this help
    
    Documentation can be found at http://nodered.org
    liumiaocn:~ liumiao$

# 代码准备 #

准备如下基于express的示例代码，将本地的node-red嵌入到此应用之中

liumiaocn:nodered liumiao$ ls
    sample.js
    liumiaocn:nodered liumiao$ cat sample.js 
    var http = require('http');
    var express = require("express");
    var RED = require("node-red");
    
    // Create an Express app
    var app = express();
    
    // Add a simple route for static content served from 'public'
    app.use("/",express.static("public"));
    
    // Create a server
    var server = http.createServer(app);
    
    // Create the settings object - see default settings.js file for other options
    var settings = { 
        httpAdminRoot:"/red",
        httpNodeRoot: "/api",
        userDir:"/Users/liumiao/.node-red",
        functionGlobalContext: {  }    // enables global context
    };
    
    // Initialise the runtime with a server and settings
    RED.init(server,settings);
    
    // Serve the editor UI from /red
    app.use(settings.httpAdminRoot,RED.httpAdmin);
    
    // Serve the http nodes UI from /api
    app.use(settings.httpNodeRoot,RED.httpNode);
    
    server.listen(8000);
    
    // Start the runtime
    RED.start();
    liumiaocn:nodered liumiao$

注意事项：/Users/liumiao/.node-red请修改为自己的本地Node-RED的相应目录。

# 依赖准备 #

使用如下命令安装所需依赖

> 执行命令：npm install express node-red

liumiaocn:nodered liumiao$ npm install express node-red
    ...省略
    + express@4.17.1
    + node-red@1.0.4
    updated 2 packages in 3.505s
    liumiaocn:nodered liumiao$

# 启动服务 #

使用如下命令启动服务，因为此Node.js服务本身没有添加功能，所以看起来似乎就是Node-RED，但是我们知道这是我们使用node在8000启动的新的服务

liumiaocn:nodered liumiao$ node sample.js 
    11 Mar 06:21:28 - [info] 
    
    Welcome to Node-RED
    ===================
    
    11 Mar 06:21:28 - [info] Node-RED version: v1.0.4
    11 Mar 06:21:28 - [info] Node.js  version: v10.15.3
    11 Mar 06:21:28 - [info] Darwin 19.2.0 x64 LE
    11 Mar 06:21:28 - [info] Loading palette nodes
    11 Mar 06:21:28 - [info] Context store  : 'default' [module=memory]
    11 Mar 06:21:28 - [info] User directory : /Users/liumiao/.node-red
    11 Mar 06:21:28 - [warn] Projects disabled : set editorTheme.projects.enabled=true to enable
    11 Mar 06:21:28 - [info] Flows file     : /Users/liumiao/.node-red/flows_liumiaocn.json
    11 Mar 06:21:28 - [warn] 
    
    ---------------------------------------------------------------------
    Your flow credentials file is encrypted using a system-generated key.
    
    If the system-generated key is lost for any reason, your credentials
    file will not be recoverable, you will have to delete it and re-enter
    your credentials.
    
    You should set your own key using the 'credentialSecret' option in
    your settings file. Node-RED will then re-encrypt your credentials
    file using your chosen key the next time you deploy a change.
    ---------------------------------------------------------------------
    
    11 Mar 06:21:28 - [info] Starting flows
    11 Mar 06:21:28 - [info] Started flows

使用/red的URL即可在8000端口确认在此Node.js应用中嵌入的Node-RED功能了  
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