crystal-docker-quickstart VS openapi-generator

Happy Crystal user and code contributor here. (Also created https://github.com/compumike/crystal-docker-quickstart in case you want to try Crystal without installing anything.) In my opinion:

- Slow compile times are still a pain for iteration.

- The REPL / interpreter mode is still rough around the edges.

As far as companies using Crystal:

- We’re using it happily in production at Heii On-Call https://heiioncall.com/status

- Kagi is using it for their search engine backend https://news.ycombinator.com/item?id=32687071

- Other companies using it list: https://crystal-lang.org/used_in_prod/

This is great Serdar.

As an alternative to Chapter 2 I’ll also share https://github.com/compumike/crystal-docker-quickstart my project template which lets you get a Crystal (currently 1.6.2) dev environment running with just Docker. Good for kicking the tires, which is what I think your audience is probably wanting to do! And then eventually can install a binary package as you suggest.

My side project https://totalrealreturns.com/ is now about 5k lines of Crystal. There are some rough edges: in particular I think it could use a better templating solution (a port of HAML would be ideal!), and there are some failure modes with the Redis connection pool that have required workarounds.

This includes unit tests: the built-in spec framework is great and much like rspec. https://crystal-lang.org/reference/1.6/guides/testing.html

I'm now starting to use Crystal for internal backend infrastructure and microservices.

For anyone who wants to kick the tires on Crystal, I built a crystal-docker-quickstart project template: https://github.com/compumike/crystal-docker-quickstart works without having to install anything locally. (Assuming you have docker.) You can have your own, home-built "Hello world" static binary in under a minute:

    git clone https://github.com/compumike/crystal-docker-quickstart.git my_app && cd my_app && ./d_dev

If you'd like to try out Crystal without installing anything locally, I've created a tiny Docker container with a Crystal project template:

https://github.com/compumike/crystal-docker-quickstart

For example, you may do:

    git clone https://github.com/compumike/crystal-docker-quickstart.git my_app

Of course you can compile the server from source if you have Go and the OpenAPI generator JAR (https://github.com/OpenAPITools/openapi-generator?tab=readme...)

Follow these steps : https://github.com/c100k/rebootx-on-prem/blob/master/.github...

And then :

(cd ./impl/http-server-go && GOARCH=amd64 GOOS=openbsd go build -o /app/rebootx-on-prem-http-server-go-openbsd-amd64 -v)

By adapting the arch if needed. Not tested, but it should work.

TL;DR: Start generating your HTTP clients and all the DTOs of the requests and responses automatically from your API, using openapi-generator instead of writing your own.

As an alternative, you can also use the official OpenAPI Generator, which is a more generic tool supporting a wide range of languages and frameworks.

I trialed generating SDKs using the OpenAPI Generator package, which was largely unsatisfactory.

If Swagger/OpenAPI is available, save yourself a lot of trouble and generate the client using OpenAPI Generator. If not, use a library like RestEase to make it significantly easier to create the client.

For a run of the mill REST API you should generate OpenAPI (Swagger) info for the API using a library like NSwag or Swashbuckle. You'd want to do this no matter what because it's documentation for the API, but the bonus is that you can use it with tools like OpenAPI Generator to create API client code and models in a variety of languages. You certainly can create an API client library manually, it would entail having a nuget package with a class library that contains the models and client code for calling the endpoints (which I'd create using a lib such as RestEase unless you just enjoy writing boilerplate code by hand). However 95% of the time it simply isn't worth creating your own lib when OpenAPI is available because once you've done it a time or two it takes less than 5 min to run the generator and create (or update) a lib.

Then you can use oapi-codegen or openapi-generator to generate the Go (or other language) SDK for it.

Yep. For frontend use, I think https://www.npmjs.com/package/openapi-typescript is the most widely-used/well-regarded, though https://www.npmjs.com/package/orval seems to me to have some nicer features like react-query support.

There are other options too, I'd just stay away from "_the_ openapi generator" (https://openapi-generator.tech/) which does a pretty poor job IMO.

Disclaimer: I'm the founder of a company doing SDKs commercially, but we don't focus on the frontend right now, and our free plan is still in beta.

Now that I have a solid way to make an Open API spec and get a functioning mock server, I'd like to take it a step further and generate an SDK to call it. Many developers use SDKs to communicate with their backend services, and tools like OpenAPI Generator enable them to do so without having to manually build them. OpenAPI Generator will take an API spec and compile it down into an SDK in the language of your choice, including front-end compatible languages like typescript-fetch.