[Question] How to return other Status Code in a successful HTTP request? about kratos HOT 7 CLOSED

Hey @init-center, great to see you back in the realm of code! 🚀

To modify the Kratos framework to return a 201 status code for successful HTTP requests instead of the default 200 status code, you need to customize the response encoder function. This function is responsible for encoding the HTTP response and setting the status code.

Here's how you can implement a custom response encoder that sets the status code to 201:

1. Define a custom response encoder function that sets the status code to 201.
2. Use the ResponseEncoder server option to apply your custom encoder.

Below is an example implementation:

package http

// CustomResponseEncoder is a custom response encoder function that sets the status code to 201.
func CustomResponseEncoder(ctx context.Context, w http.ResponseWriter, response interface{}) error {
    // Set the status code to 201 before writing the response body.
    w.WriteHeader(http.StatusCreated)

    // Write the response body. This is just an example.
    // In a real application, you would serialize the `response` object and write it to `w`.
    _, err := w.Write([]byte("Your response body here"))
    return err
}

// Then, when creating your server, use the ResponseEncoder option to use the custom encoder.
func main() {
    srv := NewServer(
        // Other server options...
        ResponseEncoder(CustomResponseEncoder), // Use the custom response encoder
    )

    // Start the server as usual.
}

This custom response encoder sets the HTTP status code to 201 (Created) for all responses. You can further customize this function to set different status codes based on the context or the response content. Remember to replace the placeholder response writing logic with your actual response encoding logic, which might involve marshaling a Go struct into JSON or another format.

The default status code in the Kratos framework is not explicitly set within the provided server.go file. However, the default behavior for HTTP status codes in Go's net/http package, which Kratos builds upon, is to set the status code to 200 OK if no other status code is explicitly written to the http.ResponseWriter during the handling of a request. This behavior is consistent with the standard HTTP server implementation in Go, where the status code defaults to 200 OK unless otherwise specified by writing a different status code to the response.

In the Kratos framework, the response handling and status code setting would typically be managed by the handlers that are registered with the server's router (s.router.HandleFunc(path, h)), and these handlers would be responsible for explicitly setting the status code as needed using the http.ResponseWriter.WriteHeader(statusCode int) method.

You can find more details in the transport/http/server.go file in the Kratos repository.

Sources

• transport/http/server.go

from kratos.

It sounds like you're discussing customizing the response encoder in the context of a specific software framework or library. If you're referring to the Kratos framework, I can certainly help guide you through the process of customizing the response encoder to return a custom status. Could you provide more details or context about the specific identifier you mentioned? This will help me provide a more tailored and accurate response.

from kratos.

Sure, I can provide an example of how to pass an identifier in the downstream context using the EncodeResponseFunc function. The EncodeResponseFunc is a type that represents a function that encodes the response. You can use this function to set a custom header in the HTTP response. Here's an example:

package http

import (
	"context"
	"net/http"

	"github.com/go-kratos/kratos/v2/transport/http"
)

func NewHTTPHandler() http.Handler {
	var opts = []http.ServerOption{
		http.ResponseEncoder(EncodeResponse),
	}
	srv := http.NewServer(opts...)
	return srv
}

func EncodeResponse(ctx context.Context, w http.ResponseWriter, response interface{}) error {
	if res, ok := response.(interface{ GetId() string }); ok {
		w.Header().Set("X-Resource-Id", res.GetId())
	}
	return http.DefaultResponseEncoder(ctx, w, response)
}

In this example, EncodeResponse is a custom response encoder function. It checks if the response object has a GetId method (which should return the identifier of the resource). If it does, it sets a custom X-Resource-Id header in the HTTP response with the value of the identifier. Finally, it calls the default response encoder to encode the response object and write it to the HTTP response.

This is just an example, and you might need to adjust it according to your needs. For instance, you might need to change the GetId method to match the method provided by your response object to get the identifier, or change the X-Resource-Id header to the header you want to use.

You can find more information about the EncodeResponseFunc function and how it's used in the Kratos framework in the transport/http/server.go file in the Kratos repository.

I hope this helps! If you have any more questions, feel free to ask.

Sources

• transport/http/binding/encode_test.go
• transport/http/server.go

from kratos.

@init-center As with @dosu-bot reply, you can return a custom status by rewriting the response encoder, but you may need to pass the identifier in ctx

from kratos.

@init-center As with @dosu-bot reply, you can return a custom status by rewriting the response encoder, but you may need to pass the identifier in ctx

ResponseEncoder type is：

// EncodeResponseFunc is encode response func.
type EncodeResponseFunc func(http.ResponseWriter, *http.Request, interface{}) error

And how to pass the identifier here in the downstream ctx?I'm not very proficient in using go. Can you give me an example? Thank you.

from kratos.

@init-center Refer this gist.

from kratos.

@init-center Refer this gist.

Thank you.

from kratos.