Microservices in Go

Part 7: Documenting RESTful APIs with OpenAPI and Swagger

Part 8: Autogenerating HTTP clients from swagger files

Generating HTTP Clients

Using swagger to generate HTTP clients, using the command:

swagger generate client <path to swagger.yaml> -A <name>

Good Pracitce:

Try to structure auto-generated snippets, by go-swagger to a folder like sdk, or maybe in other repository.

Creating tests for clients

func TestOurClient(t *testing.T) {
	cfg := client.DefaultTransportConfig().WithHost("localhost:9090")
	c := client.NewHTTPClientWithConfig(nil, cfg)
	params := products.NewListProductsParams()
	prod, err := c.Products.ListProducts(params)
	if err != nil {
		t.Fatal(err)
	}

	fmt.Printf("%#v", prod.GetPayload()[0])
}

Debugging:

Adding the correct content-type headers for our swagger spec. Debugging auto-generated code can be really painful.

rw.Header().Add("Content-Type","application/json")

Part 9: Handling CORS(Cross-Origin Resoruce Sharing)

First understanding CORS, we can use this blog post on medium here

Importing gorilla/handlers and using the CORS method, to grant allowed origins for localhost:3000

Here:

ch := gohandlers.CORS(gohandlers.AllowedOrigins([]string{"http://localhost:3000"}))

Wrapping the sm router from the mux package from gorilla into the CORS handlers sm

Part 10: Handling files using the Go Standard Library

More insights on http package