How do I properly configure Docker for my Angular 19 SSR application?

Below is a concise explanation of common pitfalls and what you may need to adjust when containerizing an Angular SSR app with Docker.

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1. Server Binding

When you run the SSR bundle (e.g. via
CMD ["npm", "run", "serve:ssr"]
which runs
node dist/chapter-alert-front-server/main.js), make sure the Express (or other Node server) code is set to listen on all network interfaces (i.e. on 0.0.0.0) rather than the default localhost. If the server binds only to localhost inside the container, external requests (mapped via port 4200) won’t reach it.
Solution:
– Update your server setup (in your main.server.ts or server.ts) so that the app listens on 0.0.0.0.
For example, if you use Express, change from:

JSCopied
app.listen(port, () => {
  console.log(`Node Express server listening on http://localhost:${port}`);
});

to

JSCopied
app.listen(port, '0.0.0.0', () => {
  console.log(`Node Express server listening on http://0.0.0.0:${port}`);
});

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2. Build vs. Serve Command

Using "build:ssr": "ng build && ng run chapter-alert-front:server" is the standard way to compile the SSR bundle. This creates the server bundle under the expected dist folder. In production (or a Docker image meant to serve the app), the command "serve:ssr": "node dist/chapter-alert-front-server/main.js" is then used to launch the app.

If you replace it with "ng run chapter-alert-front:serve", it may work on your local machine (because Angular’s dev-server configuration binds appropriately and supports live reload) but it is not the typical production setup.

Ensure:
– Your image builds the SSR bundle with the correct builder (using ng run chapter-alert-front:server) and
– Your container’s command starts the SSR bundle with Node, while the Express code handles binding as mentioned above.

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3. Volume Bind Mounts and node_modules

When using Docker Compose with volumes like:

YAMLCopied
volumes:
  - ./chapter-alert-front:/app
  - /app/node_modules

the bind mount for your source code (./chapter-alert-front:/app) will override the content that’s in the image. If node_modules were installed during image build, this volume mount could hide them if the host folder lacks the proper node_modules.

Tip:
– Consider either not mounting the entire folder in production or ensuring your host’s folder has the correct node_modules.
– For development it is common to mount local source so changes take effect, but in production you may want to rely on the built image without this volume override.

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Summary

To get your Angular SSR Docker image working as expected:

1. Ensure the Node/Express server listens on 0.0.0.0.
   Update your server code to bind on 0.0.0.0 so that the container’s port mapping works correctly.

2. Keep the build and launch steps separate.
   Use "build:ssr": "ng build && ng run chapter-alert-front:server" to produce the bundle and then use "serve:ssr": "node dist/chapter-alert-front-server/main.js" (or modify your Dockerfile CMD accordingly). This is necessary because a simple node command won’t rebind your server.

3. Review volume mounts in Docker Compose.
   If node_modules is overwritten by a bind mount, run into startup issues that may lead to “infinite load” symptoms. Adjust your volumes so that you don’t accidentally remove the installed dependencies.

Following these adjustments should help you start the SSR container just like you do locally without the infinite load issue.