How to empty a S3 bucket using the AWS SDK for GOlang?

Question

目标：使用适用于GOlang的AWS开发工具包清空现有的S3存储桶。

Answer 1

NOTE: These are code snippets that might require YOU to make changes on YOUR SIDE to make it run.

You will need to implement the below method:

  //EmptyBucket empties the Amazon S3 bucket
    func (s awsS3) EmptyBucket(bucket string) error {
        log.Info("removing objects from S3 bucket : ", bucket)
        params := &s3.ListObjectsInput{
            Bucket: aws.String(bucket),
        }
        for {
            //Requesting for batch of objects from s3 bucket
            objects, err := s.Client.ListObjects(params)
            if err != nil {
                return err
            }
            //Checks if the bucket is already empty
            if len((*objects).Contents) == 0 {
                log.Info("Bucket is already empty")
                return nil
             }
            log.Info("First object in batch | ", *(objects.Contents[0].Key))

            //creating an array of pointers of ObjectIdentifier
            objectsToDelete := make([]*s3.ObjectIdentifier, 0, 1000)
            for _, object := range (*objects).Contents {
                obj := s3.ObjectIdentifier{
                    Key: object.Key,
                }
                objectsToDelete = append(objectsToDelete, &obj)
            }
            //Creating JSON payload for bulk delete
            deleteArray := s3.Delete{Objects: objectsToDelete}
            deleteParams := &s3.DeleteObjectsInput{
                Bucket: aws.String(bucket),
                Delete: &deleteArray,
            }
            //Running the Bulk delete job (limit 1000)
            _, err = s.Client.DeleteObjects(deleteParams)
            if err != nil {
                return err
            }
            if *(*objects).IsTruncated { //if there are more objects in the bucket, IsTruncated = true
                params.Marker = (*deleteParams).Delete.Objects[len((*deleteParams).Delete.Objects)-1].Key
                log.Info("Requesting next batch | ", *(params.Marker))
            } else { //if all objects in the bucket have been cleaned up.
                break
            }
        }
        log.Info("Emptied S3 bucket : ", bucket)
        return nil
    } 

UPDATE : The latest version of AWS SDK for GO has resolved the prior issue I had.

Answer 2

Don't forget that by default ListObjects only returns up to 1000 bucket items. If you might have more than 1000, check the IsTruncated property on the return value. If true, use the NextMarker property from the return value to get the next 1000 items.

See my example in the Go dev guide: http://docs.aws.amazon.com/sdk-for-go/v1/developer-guide/s3-example-basic-bucket-operations.html#s3-examples-bucket-ops-delete-all-bucket-items

Answer 3

The AWS SDK for Go has a Amazon S3 batching abstraction. Take a look here .

Answer 4

AWS SDK now has BatchDeleteIterator that can do the job. Example provided via Amazon docs .

package main

import (
    "github.com/aws/aws-sdk-go/aws"
    "github.com/aws/aws-sdk-go/aws/session"
    "github.com/aws/aws-sdk-go/service/s3"
    "github.com/aws/aws-sdk-go/service/s3/s3manager"

    "fmt"
    "os"
)

//    go run s3_delete_objects BUCKET

func main() {
    if len(os.Args) != 2 {
        exitErrorf("Bucket name required\nUsage: %s BUCKET", os.Args[0])
    }

    bucket := os.Args[1]

    // Initialize a session in us-west-2 that the SDK will use to load
    // credentials from the shared credentials file ~/.aws/credentials.
    sess, _ := session.NewSession(&aws.Config{
        Region: aws.String("us-west-2")},
    )

    // Create S3 service client
    svc := s3.New(sess)

    // Setup BatchDeleteIterator to iterate through a list of objects.
    iter := s3manager.NewDeleteListIterator(svc, &s3.ListObjectsInput{
        Bucket: aws.String(bucket),
    })

    // Traverse iterator deleting each object
    if err := s3manager.NewBatchDeleteWithClient(svc).Delete(aws.BackgroundContext(), iter); err != nil {
        exitErrorf("Unable to delete objects from bucket %q, %v", bucket, err)
    }

    fmt.Printf("Deleted object(s) from bucket: %s", bucket)
}

func exitErrorf(msg string, args ...interface{}) {
    fmt.Fprintf(os.Stderr, msg+"\n", args...)
    os.Exit(1)
}