goa VS openapi-generator

My experience of Golang is that dependency injection doesn't really have much benefit. It felt like a square peg in a round hole exercise when my team considered it. The team was almost exclusively Java/Typescript Devs so it was something that we thought we needed but I don't believe we actually missed once we decided to not pursue it.

If you are looking at OpenAPI in Golang I can recommend having a look at https://goa.design/. It's a DSL that generates OpenAPI specs and provides an implementation of the endpoints described. Can also generate gRPC from the same definitions.

We found this removed the need to write almost all of the API layer and a lot of the associated validation. We found the generated code including the server element to be production ready from the get go.

See https://goa.design/. It automates all the comms stuff, so you just write: 1) a design file showing your functions, 2) an implantation of those functions, and 3) a very generic "main.go" (basically the same for all your services) that decides "how is this exposed over gRPC or REST or other comms?". The rest of the code is generated.

Perhaps the easiest way to find out how to do something (especially when using Meta) is to search the test cases when you have cloned the source code.

If you really need a framework, you can take a look at Echo or, for a contract-first approach, https://goa.design/

Few folks in here are (rightly) frustrated with the code generation story and broader tooling support around the OpenAPI standard. I've found a few alternative approaches quite nice to work with:

- Use a DSL to describe your service and have it spit out the OpenAPI spec as well as server stubs. In other words, I wouldn't bother writing OpenAPI directly - it's an artifact that is generated at build time. As a Go user, I quite like Goa (https://goa.design/) but there are others shared in here like TypeSpec.

- There are situations where sticking a backend-for-frontend (BFF) in front of APIs can yield great productivity boosts. For example, in the past we built a thin GraphQL proxy that calls out to a poorly structured REST API. Integrating with that was much more convenient. Most recently, I've been playing with a BFF built with tRPC (https://trpc.io/) which calls out to a REST API. It seemed to provide an even better experience if you use TypeScript on the front-end and in the BFF. It does not have a codegen step and I was really pleased with how fast I could iterate with it - granted it was a toy project.

One of the biggest issues I see is that you are using the same models for API as you are for the database. That wouldn’t fly in a real work system. And even though your doing simple CRUD I would introduce another layer for business logic. You should never have the Controller calling you database code directly. It never “stays” that simplistic. One of the easiest ways to deal with this is to use Goa. https://goa.design/ It takes care of generating your API models and it creates the Interfaces to implement for your business logic. Furthermore it creates OpenAPI documentation (something missing in this design that is a must for commercial development).

I left PHP for Go.

- with http://sqlc.dev I don't have to write ORM or model code anymore.

- with http://goa.design I can have well-documented API's that any team can generate a client for in any language. It also generates the HTTP JSON and gRPC servers for me so I can focus on my logic.

- with https://github.com/99designs/gqlgen I can define GraphQL revolvers that play well with sqlc (any RDBMS) or I can use a key-value store.

- speaking of key-value stores, Go allows them to be embedded! Even SQLite now has the https://litestream.io/ project to make it super simple to use a durable, always backed-up SQLite database even in a serverless context.

Go is faster, uses less memory, and has really-well designed stdlib without all the bugs I used to face trying to use the PHP stdlib.

Goa and Kong are some of the best frameworks to develop and deploy microservices. They provide features such as out-of-the-box support for service discovery, routing and authentication that make it easier to build more complex applications. There are also newer architectural frameworks with less steep learning curves like GPTDeploy that lets you build and deploy microservices with a single command.

Or the one we use at work: https://goa.design/ Goa does a lot more and maybe more than you need. We use it as it can generate both REST and gRPC as well as API models and OpenAPI documentation (JSON and YAML).

Disclaimer: We're an early adopter of Stainless at Mux.

I've spent more of my time than I'd like to admit managing both OpenAPi spec files [1] and fighting with openapi-generator [2] than any sane person should have to. While it's great having the freedom to change the templates an thus generated SDKs you get with using that sort of approach, it's also super time consuming, and when you have a lot of SDKs (we have 6 generated SDKs), in my experience it needs someone devoted to managing the process, staying up with template changes etc.

Excited to see more SDK languages come to Stainless!

[1] https://www.mux.com/blog/an-adventure-in-openapi-v3-api-code...

[2] https://github.com/OpenAPITools/openapi-generator

As a result, the following specification can be used to generate clients in a number of different languages via OpenAPI Generator.

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.