sts_assumerole.go

package main

import (
	"fmt"
	"net/url"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/credentials/stscreds"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3"
)

func main() {
	sess := session.Must(session.NewSession())
	creds := stscreds.NewCredentials(sess, "arn:aws:iam::ACCOUNT_ID:role/YOUR_ROLE_NAME")
	svc := s3.New(sess, &aws.Config{Credentials: creds})

	source := url.QueryEscape("SRC_BUCKET_NAME/SRC_OBJECT_KEY")

	params := &s3.CopyObjectInput{}
	params.SetBucket("DEST_BUCKET_NAME")
	params.SetKey("DEST_OBJECT_KEY")
	params.SetCopySource(source)

	req, resp := svc.CopyObjectRequest(params)

	err := req.Send()
	if err == nil {
		fmt.Println(resp)
	} else {
		fmt.Println(err)
	}
}