Webpack breaking changes for builtin modules on Gatsby site

Question

I've tried deploying my Gatsby site to Netlify, but I keep getting these errors for various node modules whenever I try to deploy. I've tried making a webpack.config.js file and including both of the suggested solutions to no avail. I've also tried using alias instead of fallback, adding a browser section to the package.json file which sets the modules to false, and adding a target property in the webpack.config.js file as some other stackoverflow answers have suggested, but I'm still pretty stuck. I don't have any prior experience to webpack and have been doing my best to look for answers. Is there some sort of special configuration for this with Gatsby that I'm missing?

Error message

10:37:20 AM: error Generating JavaScript bundles failed
10:37:20 AM: Can't resolve 'stream' in '/opt/build/repo/node_modules/cipher-base'
10:37:20 AM: If you're trying to use a package make sure that 'stream' is installed. If you're trying to use a local file make sure that the path is correct.
10:37:20 AM: BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
10:37:20 AM: This is no longer the case. Verify if you need this module and configure a polyfill for it.
10:37:20 AM: If you want to include a polyfill, you need to:
10:37:20 AM:    - add a fallback 'resolve.fallback: { "stream": require.resolve("stream-browserify") }'
10:37:20 AM:    - install 'stream-browserify'
10:37:20 AM: If you don't want to include a polyfill, you can use an empty module like this:
    resolve.fallback: { "stream": false }

webpack.config.js

module.exports = {
    target: 'node14.17',
    resolve: {
        fallback: {
            assert: require.resolve("assert/"),
            crypto: require.resolve("crypto-browserify"),
            http:  require.resolve("stream-http"),
            https: require.resolve("https-browserify"),
            os: require.resolve("os-browserify/browser"),
            stream: require.resolve("stream-browserify"),
        },
    },
}

package.json

{
  "name": "gatsby-starter-default",
  "private": true,
  "description": "A simple starter to get up and developing quickly with Gatsby",
  "version": "0.1.0",
  "author": "Kyle Mathews <mathews.kyle@gmail.com>",
  "dependencies": {
    "crypto-browserify": "^3.12.0",
    "ethers": "^5.4.5",
    "gatsby": "^3.11.1",
    "gatsby-plugin-gatsby-cloud": "^2.11.0",
    "gatsby-plugin-google-fonts": "^1.0.1",
    "gatsby-plugin-image": "^1.11.0",
    "gatsby-plugin-manifest": "^3.11.0",
    "gatsby-plugin-offline": "^4.11.0",
    "gatsby-plugin-react-helmet": "^4.11.0",
    "gatsby-plugin-sharp": "^3.11.0",
    "gatsby-source-filesystem": "^3.11.0",
    "gatsby-transformer-sharp": "^3.11.0",
    "https-browserify": "^1.0.0",
    "os-browserify": "^0.3.0",
    "prop-types": "^15.7.2",
    "react": "^17.0.1",
    "react-dom": "^17.0.1",
    "react-helmet": "^6.1.0",
    "stream-browserify": "^3.0.0",
    "stream-http": "^3.2.0",
    "web3": "^1.5.2"
  },
  "devDependencies": {
    "prettier": "2.3.2"
  },
  "browser": {
    "assert": false,
    "crypto": false,
    "http":   false,
    "https":  false
  },
  "keywords": [
    "gatsby"
  ],
  "license": "0BSD",
  "scripts": {
    "build": "gatsby build",
    "develop": "gatsby develop",
    "format": "prettier --write \"**/*.{js,jsx,ts,tsx,json,md}\"",
    "start": "npm run develop",
    "serve": "gatsby serve",
    "clean": "gatsby clean",
    "test": "echo \"Write tests! -> https://gatsby.dev/unit-testing\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/gatsbyjs/gatsby-starter-default"
  },
  "bugs": {
    "url": "https://github.com/gatsbyjs/gatsby/issues"
  }
}

Answer 1

In Gatsby, you can't define the webpack configuration like you did because Gatsby ships its own webpack.config.js as you can read in Gatsby's glossary.

However, Gatsby allows you to add a custom webpack configuration by exposing onCreateWebpackConfig method in your gatsby-node.js file.

So:

module.exports = {
    target: 'node14.17',
    resolve: {
        fallback: {
            assert: require.resolve("assert/"),
            crypto: require.resolve("crypto-browserify"),
            http:  require.resolve("stream-http"),
            https: require.resolve("https-browserify"),
            os: require.resolve("os-browserify/browser"),
            stream: require.resolve("stream-browserify"),
        },
    },
}

Should become:

exports.onCreateWebpackConfig = ({ actions }) => {
  actions.setWebpackConfig({
   resolve: {
      fallback: {
          assert: require.resolve("assert/"),
          crypto: require.resolve("crypto-browserify"),
          http:  require.resolve("stream-http"),
          https: require.resolve("https-browserify"),
          os: require.resolve("os-browserify/browser"),
          stream: require.resolve("stream-browserify"),
      },
    },
  })
}

As I said, onCreateWebpackConfig is a method exposed only in the gatsby-node.js file so that snippet must be placed there.