s3_put_bucket_acl.go

// snippet-comment:[These are tags for the AWS doc team's sample catalog. Do not remove.]
// snippet-sourceauthor:[Doug-AWS]
// snippet-sourcedescription:[Sets the ACL on an S3 bucket.]
// snippet-keyword:[Amazon Simple Storage Service]
// snippet-keyword:[Amazon S3]
// snippet-keyword:[GetBucketAcl function]
// snippet-keyword:[PutBucketAcl function]
// snippet-keyword:[Go]
// snippet-sourcesyntax:[go]
// snippet-service:[s3]
// snippet-keyword:[Code Sample]
// snippet-sourcetype:[full-example]
// snippet-sourcedate:[2018-03-16]
/*
   Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.

   This file is licensed under the Apache License, Version 2.0 (the "License").
   You may not use this file except in compliance with the License. A copy of
   the License is located at

    http://aws.amazon.com/apache2.0/

   This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, either express or implied. See the License for the
   specific language governing permissions and limitations under the License.
*/

package main

import (
    "github.com/aws/aws-sdk-go/aws/session"
    "github.com/aws/aws-sdk-go/service/s3"
    
    "fmt"
    "os"
)

// Allows person with EMAIL address PERMISSION access to BUCKET
// If PERMISSION is missing, they get READ access.
//
// Usage:
//    go run s3_put_bucket_acl.go BUCKET EMAIL [PERMISSION]
func main() {
    if len(os.Args) < 3 {
        exitErrorf("Bucket name and email address required; permission optional (READ if omitted)\nUsage: go run", os.Args[0], "BUCKET EMAIL [PERMISSION]")
    }

    bucket := os.Args[1]
    address := os.Args[2]

    permission := "READ"

    if len(os.Args) == 4 {
        permission = os.Args[3]

        if !(permission == "FULL_CONTROL" || permission == "WRITE" || permission == "WRITE_ACP" || permission == "READ" || permission == "READ_ACP") {
            fmt.Println("Illegal permission value. It must be one of:")
            fmt.Println("FULL_CONTROL, WRITE, WRITE_ACP, READ, or READ_ACP")
            os.Exit(1)

        }
    }

    userType := "AmazonCustomerByEmail"

    // Initialize a session that loads credentials from the shared credentials file ~/.aws/credentials
    // and the region from the shared configuration file ~/.aws/config.
    sess := session.Must(session.NewSessionWithOptions(session.Options{
        SharedConfigState: session.SharedConfigEnable,
    }))

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

    // Get existing ACL
    result, err := svc.GetBucketAcl(&s3.GetBucketAclInput{Bucket: &bucket})
    if err != nil {
        exitErrorf(err.Error())
    }

    owner := *result.Owner.DisplayName
    ownerId := *result.Owner.ID

    // Existing grants
    grants := result.Grants

    // Create new grantee to add to grants
    var newGrantee = s3.Grantee{EmailAddress: &address, Type: &userType}
    var newGrant = s3.Grant{Grantee: &newGrantee, Permission: &permission}

    // Add them to the grants
    grants = append(grants, &newGrant)

    params := &s3.PutBucketAclInput{
        Bucket: &bucket,
        AccessControlPolicy: &s3.AccessControlPolicy{
            Grants: grants,
            Owner: &s3.Owner{
                DisplayName: &owner,
                ID:          &ownerId,
            },
        },
    }

    // Set bucket ACL
    _, err = svc.PutBucketAcl(params)
    if err != nil {
        exitErrorf(err.Error())
    }

    fmt.Println("Congratulations. You gave user with email address", address, permission, "permission to bucket", bucket)
}

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