Integrate file uploads and S3 Bucket

main.go

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"os"
	"time"

	"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/aws/aws-sdk-go-v2/service/s3/types"
)

func main() {
	mux := http.NewServeMux()

	mux.HandleFunc("/", handleUpload)

	log.Println("Server listening on port 8000")
	http.ListenAndServe(":8000", mux)
}

func handleUpload(w http.ResponseWriter, r *http.Request) {
	r.ParseMultipartForm(1 * 1024 * 1024 * 10) // 10MB

	// assuming you set the `file` field in the formData
	file, handler, err := r.FormFile("file")
	if err != nil {
		respond(w, 500, err.Error())
		return
	}
	defer file.Close()

	uploader, err := newS3Client()
	if err != nil {
		respond(w, 500, err.Error())
		return
	}

	// get the content type from the header
	contentType := handler.Header.Get("Content-Type")
	key := fmt.Sprintf("%d-%s", time.Now().Unix(), handler.Filename)

	_, err = uploader.Upload(r.Context(), &s3.PutObjectInput{
		Bucket:      aws.String(os.Getenv("AWS_BUCKET")),
		Key:         aws.String(key),
		Body:        file,
		ACL:         types.ObjectCannedACL("public-read"),
		ContentType: aws.String(contentType),
	})

	if err != nil {
		respond(w, 500, err.Error())
		return
	}

	respond(w, 200, "Uploaded")
}

func respond(w http.ResponseWriter, status int, message string) {
	w.WriteHeader(status)
	fmt.Fprint(w, message)
}

func newS3Client() (*manager.Uploader, error) {
	cfg, err := config.LoadDefaultConfig(context.TODO(), config.WithRegion(os.Getenv("AWS_REGION")))
	if err != nil {
		return nil, err
	}

	storage := s3.NewFromConfig(cfg)
	return manager.NewUploader(storage), nil

}