Webpack devserver with Nginx and Docker: polling info on the wrong address

问题

I have 2 containers in Docker:

• Node.js + Webpack devserver which listen on port 3000
• Nginx which listen on port 80 (mapped on host port 8080 through docker-compose file)

Nginx correctly proxy requests to the node container and I can access the node app at http://localhost:8080, but for some reasons there are other polling requests of the type http://localhost:3000/sockjs-node/info?t=1570780621084 that fail (net::ERR_CONNECTION_REFUSED) because on the host only Nginx on port 8080 is visible. I think that these polling requests should be directed to Nginx (http://localhost:8080/sockjs-node/info?t=1570780621084) but I don't know what I have to change on the Webpack devserver configuration to fix that.

This is the web pack devserver configuration:

const path = require("path");
const webpack = require("webpack");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const { CleanWebpackPlugin } = require("clean-webpack-plugin");
const {
    BUILD_DIR,        
} = require("./config/config");

module.exports = {
    entry: {
        bundle: [
            "@babel/polyfill", 
            "./src/app.js",
        ]
    },

    output: {
        path: BUILD_DIR,
        filename: "[name].[hash].js"
    },

    devtool: "inline-source-map",

    devServer: {
        host: "localhost",
        port: 3000,        
        contentBase: BUILD_DIR,
        historyApiFallback: false,
        hot: true,
        inline: true,
        watchOptions: {
            poll: true
        },
        disableHostCheck: true,
    },

    module: {
        rules: [
            {
                test: /\.(js|jsx)$/,
                exclude: /node_modules/,
                use: {
                    loader: "babel-loader"
                }
            },
            {
                test: /\.css$/,
                use: ["style-loader", "css-loader"],
            },
            {
                test: /\.scss$/,
                use: ["style-loader", "css-loader", "sass-loader"]
            }
        ],
    },

    plugins: [
        new CleanWebpackPlugin(),

        new HtmlWebpackPlugin({
            template: "src/index.html",
            filename: "index.html",
            inject: true
        }),
    ]
};

This is the Nginx configuration:

upstream reactclient {
    server react-client:3000 fail_timeout=20s max_fails=10;
}

server {
    listen 80;

    location / {
        proxy_pass http://reactclient;
    }   

    location /sockjs-node/ {
        proxy_set_header X-Real-IP  $remote_addr;
        proxy_set_header X-Forwarded-For $remote_addr;
        proxy_set_header Host $host;

        proxy_pass http://reactclient;
        proxy_redirect off;

        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";  
    }
}

What I've tried so far was to add the following in the entry of the devserver config, but id didn't work.

entry: {
        bundle: [
            `webpack-dev-server/client?http://localhost:8080`,
            "webpack/hot/dev-server",
            "@babel/polyfill", 
            "./src/app.js",
        ]
    },

How can I make Webpack devserver working correctly with Nginx in Docker?

回答1:

Assuming dev-server is running on port 3000 and nginx on port 8080, this is what has worked for me (see web-devserver public option):

Nginx default.conf

upstream reactclient {
    server react_client:3000 fail_timeout=20s max_fails=100;
}

server {
    listen 80;

    location / {
        proxy_pass http://reactclient;
    }       

    location /sockjs-node/ {
        proxy_set_header X-Real-IP  $remote_addr;
        proxy_set_header X-Forwarded-For $remote_addr;
        proxy_set_header Host $host;

        proxy_pass http://reactclient;
        proxy_redirect off;

        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";  
    }
}

Webpack

// [...]
devServer: {
        host: '0.0.0.0',
        port: 3000,
        public: `localhost:8080`,
        historyApiFallback: false,
        hot: true,
        inline: true,
        watchOptions: {
            aggregateTimeout: 300,
            poll: 1000,
            ignored: /node_modules/,
        },
        disableHostCheck: true,
    },
// [...]

回答2:

I had a similar problem with the requests similar to

http://localhost:3000/sockjs-node/info?t=1570780621084

and the same error

(net::ERR_CONNECTION_REFUSED)

I have a react application on frontend and a nodejs application on backend. Each in a separate docker container. I use webpack-dev-server to run react application, that uses sockjs library that generates this sockjs-node request for its development purposes.

So to get it to work correctly I wrote the next options in the devServer section

host: '0.0.0.0', // you can change this ip with your ip
port: 4001, // ssl defult port number
public: 'https://localhost:9001',
publicPath: '/',

There are the ports in my docker-compose for the react application (one for HTTP and second for HTTPS)

ports:
  - 9000:4000
  - 9001:4001

So the 'public' option set to using port 9001 that accessible on the host machine. And I use it when want to load my application in a browser https://localhost:9001. Also, this URL used to load main.js script by the application.

But the 'port' option I have set to 4001. This port used by sockjs library to generate the request that we have problems with.

So be sure that you have opened an SSL port in a docker container with application that uses webpack-dev-server. And that you set the right values for 'public' and 'port' options in the devServer section of your webpack config file.

来源：https://stackoverflow.com/questions/58337248/webpack-devserver-with-nginx-and-docker-polling-info-on-the-wrong-address