Grpc: how to implement the restful API for file uploading?

Introduce

This article will show you how to gRPC File upload in microservice Restful API？

Why do you need such an article ？

gRPC We can go through Streaming To transfer large files to each other , But by grpc-gateway on gRPC We can't achieve . therefore , Need to bypass gRPC Directly in grpc-gateway Add API.

We will use rk-boot To start up gRPC service .

Please visit the following address for a complete tutorial ：https://rkdev.info/cnhttps://rkdocs.netlify.app/cn ( spare )

install

go get github.com/rookie-ninja/rk-boot
go get github.com/rookie-ninja/rk-grpc

Quick start

rk-boot Integrated by default grpc-gateway, And will start by default .

1. establish boot.yaml

---
grpc:
  - name: greeter                   # Name of grpc entry
    port: 8080                      # Port of grpc entry
    enabled: true                   # Enable grpc entry

2. establish main.go

Be careful ,grpcEntry.GwMux.HandlePath() Be sure to write boot.Bootstrap() after , Otherwise Panic.

package main

import (
	"context"
	"fmt"
	"github.com/rookie-ninja/rk-boot"
	"github.com/rookie-ninja/rk-grpc/boot"
	"net/http"
)

// Application entrance.
func main() {
	// Create a new boot instance.
	boot := rkboot.NewBoot()

	// Bootstrap
	boot.Bootstrap(context.Background())

	// Get grpc entry with name
	grpcEntry := boot.GetEntry("greeter").(*rkgrpc.GrpcEntry)

	// Attachment upload from http/s handled manually
	grpcEntry.GwMux.HandlePath("POST", "/v1/files", handleBinaryFileUpload)

	// Wait for shutdown sig
	boot.WaitForShutdownSig(context.Background())
}

func handleBinaryFileUpload(w http.ResponseWriter, req *http.Request, params map[string]string) {
	err := req.ParseForm()
	if err != nil {
		http.Error(w, fmt.Sprintf("failed to parse form: %s", err.Error()), http.StatusBadRequest)
		return
	}

	f, header, err := req.FormFile("attachment")
	if err != nil {
		http.Error(w, fmt.Sprintf("failed to get file 'attachment': %s", err.Error()), http.StatusBadRequest)
		return
	}
	defer f.Close()

	fmt.Println(header)

	//
	// Now do something with the io.Reader in `f`, i.e. read it into a buffer or stream it to a gRPC client side stream.
	// Also `header` will contain the filename, size etc of the original file.
	//
}

3. verification

$ curl -X POST -F "[email protected]" localhost:8080/v1/files