server.go

package main

import (
	"context"
	"mime/multipart"
	"net/http"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/feature/s3/manager"
	"github.com/aws/aws-sdk-go-v2/service/s3"
	"github.com/labstack/echo/v4"
	"github.com/labstack/echo/v4/middleware"
)

type UploadResult struct {
	Path string `json:"path" xml:"path"`
}

func upload(c echo.Context) error {
	file, err := c.FormFile("file")
	if err != nil {
		return err
	}
	src, err := file.Open()
	if err != nil {
		return err
	}
	defer src.Close()
	result, err := UploadToS3(c, file.Filename, src)
	if err != nil {
		return err
	}
	data := &UploadResult{
		Path: result,
	}
	return c.JSON(http.StatusOK, data)
}

func UploadToS3(c echo.Context, filename string, src multipart.File) (string, error) {
	logger := c.Logger()
	cfg, err := config.LoadDefaultConfig(context.TODO())
	if err != nil {
		logger.Fatal(err)
		return "", err
	}
	client := s3.NewFromConfig(cfg)
	uploader := manager.NewUploader(client)
	result, err := uploader.Upload(context.TODO(), &s3.PutObjectInput{
		Bucket: aws.String("explore-go-berv"),
		Key:    aws.String(filename),
		Body:   src,
	})
	if err != nil {
		logger.Fatal(err)
		return "", err
	}
	return result.Location, nil
}

func HelloWorld(c echo.Context) error {
	return c.String(http.StatusOK, "Hello, World!")
}

func main() {
	e := echo.New()
	e.Use(middleware.Logger())
	e.GET("/", HelloWorld)
	e.POST("/upload", upload)

	e.Logger.Fatal(e.Start(":1323"))
}