How to put Vue.js in production mode using webpack 2.7?

I've got an existing code base in which Vue.js has performance problems. I also see this notice in the browser console:

so I guess an easy fix could be to put Vue into production mode.

In the suggested link I try to follow the instructions for webpack. We're on Webpack version 2.7 (current stable version is 4.20). In the instructions it says that in Webpack 3 and earlier, you’ll need to use DefinePlugin:

var webpack = require('webpack')
module.exports = {
  // ...
  plugins: [
    // ...
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': JSON.stringify('production')
    })
  ]
}

So in my package.json I've got a build script defined:

To build for production I run yarn run build and it runs a build.js file (paste here) which in turn calls webpack.base.conf.js (paste here) and webpack.prod.conf.js (paste here).

As you can see in the paste I use the DefinePlugin as suggested by the docs.

I also found a file called vue-loader.conf.js (paste here) and to be sure I also added the DefinePlugin in there as well.

I can run yarn run build which ends without errors, but when serve the site over Apache and open the browser it still shows the notification that we're in development mode.

To be sure it actually uses the files created by webpack I completely removed the folder /public/webpack/ and checked that the webinterface didn't load correctly without the missing files and then built again to see if it loaded correctly after the command finished. So it does actually use the files built by this webpack process. But Vue is actually not created in production mode.

Does anybody know what I'm doing wrong here? All tips are welcome!

The problem may be in your 'webpack.base.conf.js' as i suspected, thank you for sharing it, upon searching i've found an issue resolving your 'production not being detected' problem on github here

The solution requires that you change 'vue$': 'vue/dist/vue' to 'vue$': vue/dist/vue.min in production.

You will find the original answer as: