Upload to S3 using PerRequestContext

main.go

package main

import (
	"context"
	"fmt"
	"log"
	"os"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/aws/external"
	"github.com/aws/aws-sdk-go-v2/service/s3"
	"github.com/aws/aws-sdk-go-v2/service/s3/s3manager"
)

func main() {
	bucket := "mybucket"
	cfg, err := external.LoadDefaultAWSConfig()

	if err != nil {
		log.Fatal("unable to load SDK config, " + err.Error())
	}
	cfg.Region = "us-east-2"
	cfg.Retryer = aws.DefaultRetryer{NumMaxRetries: 10}
	uploader := s3manager.NewUploader(cfg)

	svc := s3.New(cfg)
	req := svc.HeadBucketRequest(&s3.HeadBucketInput{Bucket: &bucket})
	_, err = req.Send()
	if err != nil {
		log.Fatal(err)
	}

	f, err := os.Open("big-file")
	if err != nil {
		log.Fatal(err)
	}

	// details of file to upload
	params := &s3manager.UploadInput{
		Bucket: aws.String(bucket),
		Body:   f,
		Key:    aws.String("big-file"),
	}

	// upload file
	ctx := context.Background()
	resp, err := uploader.UploadWithContext(ctx, params, func(u *s3manager.Uploader) {
		u.MaxUploadParts = 10000     // set to maximum allowed by s3
		u.PartSize = 5 * 1024 * 1024 // 5MB
		u.RequestOptions = append(u.RequestOptions, PerRequestContext())
	})
	fmt.Println(resp)
	fmt.Println(err)
}

// PerRequestContext sets a custom context per request to S3
//
// The DefaultUploadMgr runs with concurrency of 5 goroutines
// This helps when you might have slow upload but you don't want to set a context
// that times out for the entire upload, it's easier to reason about per-part
func PerRequestContext() aws.Option {
	return func(r *aws.Request) {
		ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
		r.Handlers.Complete.PushBack(func(f *aws.Request) {
			cancel()
		})
		r.SetContext(ctx)
	}
}