Nx OpenNext example

This repository is intended as an example for integrating open-next within an Nx monorepo.

This was made possible by the recently introduced app-path and build-output-path options, released in open-next@2.2.1.

Setup

This repository exposes two different projects lined out in the following chapters.

libs/nx-open-next

A custom Nx plugin which exposes a build executor.

In it's most simple form the open-next command can be executed in the following manner:

pnpm open-next build --build-command "pnpm nx build open-next-example-web" --app-path "apps/open-next-example-web" --build-output-path "dist/apps/open-next-example-web"

Sadly enough Nx executors don't support ESM at the moment: nrwl/nx#17390.

Because of this limitation we're forced to execute the open-next command as a child process in the workspace instead of importing the build function from open-next/build. Currently only ESM is exposed from open-next.

Options

The Nx plugin sets this command up with the following provided options:

buildTarget: the Nx build target to use in the format project:target or project:target:configuration.
sourceRoot: the path to the root of the Next.js application's source code.
buildCommand?: maps directly to the build-command flag. This is defaulted to "exit 0" because most projects can be built using Nx's dependsOn project option, read more about this in apps/open-next-example-web.

apps/open-next-example-web

An example Next.js application which integrates the nx-open-next plugin.

next.config.js

It's important to note that the Next app is built in standalone mode. When generating a new Next app make sure to include the following option in next.config.js:

const nextConfig = {
  output: 'standalone',
  ...
};

project.json

The project.json is set up in a way to utilise the Nx cache for both the Next.js build and open-next transforming your build output.

In order to achieve this you can rename the default Next.js build target to the build-next target. The reason for this is that we're actually going to use the build target for executing open-next as the entry point.

The build target looks something like the following:

{
    ...
    "targets" {
        ...
        "build": {
            "executor": "@nx-open-next/nx-open-next:build",
            "outputs": ["{options.outputPath}"],
            "defaultConfiguration": "production",
            "options": {
                "buildTarget": "open-next-example-web:build-next",
                "sourceRoot": "apps/open-next-example-web"
            },
            "dependsOn": ["build-next"]
        }
    }
},

Specifcally note the dependsOn option. This will make sure the build-next target is ran with the same configuration.

This makes sure that both commands are using Nx as the execution layer, allowing these outputs to be cached by Nx.

Publishing and other concerns

This repository is meant as an example repository for the Nx enthousiasts in the SST Discord.

I will soon look into publishing this as an Nx plugin. There are several possibilities of expanding this further, potentially even by supporting a custom Nx generator which includes this setup by default.

If you have any issues in the meantime setting this up, or have any improvements for this setup, feel free to reach out. You can create an issue on this repository or reach out on the SST Discord, make sure to tag my handle @lorenzodejong.

lorenzodejong/nx-open-next