How to enable http2 protocol in nuxt.js

Question

How to enable http2 protocol in nuxt.js app? I have added SSL certificates and enabled modern mode, played with render>http2 settings in nuxt.config.js, but no matter what I try app still serves request with standard http/1.1 protocol. I can't seem to find anything about it in the documentation either.

Here is my nuxt.config.js:

import path from 'path'
import fs from 'fs'

export default {
  server: {
    https: {
      key: fs.readFileSync(path.resolve(__dirname, 'certs/localhost.key')),
      cert: fs.readFileSync(path.resolve(__dirname, 'certs/localhost.crt'))
    }
  },

  mode: 'universal',
  modern: true,
  render: {
    http2: {
      push: true, pushAssets: null
    }
  },
  /*
  ** Headers of the page
  */
  head: {
    title: process.env.npm_package_name || '',
    meta: [
      {charset: 'utf-8'},
      {name: 'viewport', content: 'width=device-width, initial-scale=1'},
      {hid: 'description', name: 'description', content: process.env.npm_package_description || ''}
    ],
    link: [
      {rel: 'icon', type: 'image/x-icon', href: '/favicon.ico'}
    ]
  },
  /*
  ** Customize the progress-bar color
  */
  loading: {color: '#fff'},
  /*
  ** Global CSS
  */
  css: [
  ],
  /*
  ** Plugins to load before mounting the App
  */
  plugins: [
  ],
  /*
  ** Nuxt.js dev-modules
  */
  buildModules: [
    // Doc: https://github.com/nuxt-community/eslint-module
    '@nuxtjs/eslint-module',
    // Doc: https://github.com/nuxt-community/nuxt-tailwindcss
    '@nuxtjs/tailwindcss'
  ],
  /*
  ** Nuxt.js modules
  */
  modules: [
    // Doc: https://axios.nuxtjs.org/usage
    '@nuxtjs/axios',
    '@nuxtjs/pwa',
    // Doc: https://github.com/nuxt-community/dotenv-module
    '@nuxtjs/dotenv'
  ],
  /*
  ** Axios module configuration
  ** See https://axios.nuxtjs.org/options
  */
  axios: {
  },
  /*
  ** Build configuration
  */
  build: {
    /*
    ** You can extend webpack config here
    */
    extend(config, ctx) {
    }
  }
}

Thank in advance.

Answer 1

You should set your mode to modern:

  mode: 'modern'

And specify in the render.http2.pushAssets the actual assets that should be pushed (you currently have null in your sample code).

For example:

export default {
  // ...
  render: {
    http2: {
      push: true,
      pushAssets: [
        '/css/main.css',
        '/js/main.js'
      ]
    }
  }
};