RFC: Improvements to webserver

[vlidholt]

Serverpod comes with a built-in web server called Relic. It's still experimental, and it would be nice to clean it up and make it top-notch, like the rest of Serverpod. 🚀

There are many use cases for the web server:

• Serve a Flutter web app.
• Build websites that use the same database as the API server.
• Create webhooks.
• Create REST APIs that look a specific way. I.e., complete control over status code, request types, headers, etc.

The main benefit of having a good web server bundled with Serverpod is that developers can use the Serverpod sessions and ORM. This means that a lot of code can be shared between the generated API and a website or custom API.

Improvements

The overall architecture for Relic looks sound, but it would be nice to improve in certain areas.

• Routing. Providing an easier way to pattern-match paths and automatically extract components from them would be nice. We can take inspiration from packages like Shelf, Dart Frog, and Pharaoh here. Looking at packages from other languages would also be smart. Let's be best in class here!
• Middleware. Add support for middleware, as it can be used for things like custom logging, authentication, data validation, error handling, or other logic. Again, we should look at other frameworks to do something really good here.
• Authentication. It should be possible (through pre-built middleware?) to access the same authentication system as for Serverpod's generated endpoints.
• Sharing static files. There is a route made for sharing a directory of static files. It works, but the API could be clearer and easier to understand. We should also support more MIME types. It should also be possible to add additional types.
• Make Flutter web easy. Serving a Flutter app may be the most common reason to use Relic. We should make it very simple to set up, compile, and host a Flutter web app.
• Support modules. Make it possible to place web routes in Serverpod modules. This would make building modules for integrations like payments requiring custom webhooks easier.
• Tests. Improve the test suite for Relic. There are a couple of tests, but it would be nice to cover a larger surface. Documentation. Add examples and proper documentation for the webserver.

Ideas for the future

These are ideas that we can add in the future without breaking any of the new core features.

• Improved templates. Relic has a template engine that uses the Mustache library. A template combined with a Dart class forms a Widget, which is analogous to a Flutter widget. It would be cool to support Relic widgets that resemble some of the static Flutter widgets (Container, Row, Padding, Text, etc). We could also generate widgets (possibly without a template file) that correspond to all the default tags in HTML.

[codekeyz]

Awesome stuff @vlidholt. Is Relic added in the alpha version currently on pub.dev? I'd love to see how this turns out.

[vlidholt]

@codekeyz, Relic is already part of Serverpod 1.0 and later.

[dkbast]

Supporting modules is probably one of the most important features if the goals is to have a "module economy" where there are modules for most common use cases (and not just libraries which you then still need to plugin yourself). Especially receiving and sending to webhooks is something that will probably be very valuable (e.g. make, zapier and all the payment providers as well as newsletter, marketing & crm tools or when working with any third party ecommerce framework).

[Maksimka101]

From my point of view most people will use the webserver for webhooks and static files serving. So I'd like to see the high level routes api as well as a convenient file serving functionality. Hope this issue is the right place to share my expectations :)

[ali-esmailie-dev]

I can't find any documentation for the relic. Please help me to implement Rest API with relic. @vlidholt