winterbaume-s3

S3 service implementation for winterbaume.

Coverage

Metric	Value
Service	S3
AWS model	s3
Protocol	restXml
winterbaume coverage	103/107 operations (96.3%)
stubs (routed, returns empty/default)	4/107 operations (3.7%)
moto coverage	73/107 operations (68.2%)
floci coverage	51/107 operations (47.7%)
kumo coverage	36/107 operations (33.6%)
Coverage report date	2026-05-13

Server-mode usage

Start winterbaume-server and point the AWS CLI at it:

cargo run -p winterbaume-server -- --host 127.0.0.1 --port 5555

export AWS_ENDPOINT_URL=http://localhost:5555
aws s3api list-buckets

Example

use aws_sdk_s3::config::BehaviorVersion;
use winterbaume_core::MockAws;
use winterbaume_s3::S3Service;

#[tokio::main]
async fn main() {
    let mock = MockAws::builder().with_service(S3Service::new()).build();

    let config = aws_config::defaults(BehaviorVersion::latest())
        .http_client(mock.http_client())
        .credentials_provider(mock.credentials_provider())
        .region(aws_sdk_s3::config::Region::new("us-east-1"))
        .load()
        .await;

    let client = aws_sdk_s3::Client::new(&config);

    client
        .create_bucket()
        .bucket("example-bucket")
        .send()
        .await
        .expect("create_bucket should succeed");
    let resp = client
        .list_buckets()
        .send()
        .await
        .expect("list_buckets should succeed");
    println!(
        "S3 buckets: {:?}",
        resp.buckets()
            .iter()
            .map(|b| b.name().unwrap_or_default())
            .collect::<Vec<_>>()
    );
}

Implemented APIs (103)

• AbortMultipartUpload
• CompleteMultipartUpload
• CopyObject
• CreateBucket
• CreateBucketMetadataConfiguration
• CreateBucketMetadataTableConfiguration
• CreateMultipartUpload
• DeleteBucket
• DeleteBucketAnalyticsConfiguration
• DeleteBucketCors
• DeleteBucketEncryption
• DeleteBucketIntelligentTieringConfiguration
• DeleteBucketInventoryConfiguration
• DeleteBucketLifecycle
• DeleteBucketMetadataConfiguration
• DeleteBucketMetadataTableConfiguration
• DeleteBucketMetricsConfiguration
• DeleteBucketOwnershipControls
• DeleteBucketPolicy
• DeleteBucketReplication
• DeleteBucketTagging
• DeleteBucketWebsite
• DeleteObject
• DeleteObjectTagging
• DeleteObjects
• DeletePublicAccessBlock
• GetBucketAbac
• GetBucketAccelerateConfiguration
• GetBucketAcl
• GetBucketAnalyticsConfiguration
• GetBucketCors
• GetBucketEncryption
• GetBucketIntelligentTieringConfiguration
• GetBucketInventoryConfiguration
• GetBucketLifecycleConfiguration
• GetBucketLocation
• GetBucketLogging
• GetBucketMetadataConfiguration
• GetBucketMetadataTableConfiguration
• GetBucketMetricsConfiguration
• GetBucketNotificationConfiguration
• GetBucketOwnershipControls
• GetBucketPolicy
• GetBucketReplication
• GetBucketRequestPayment
• GetBucketTagging
• GetBucketVersioning
• GetBucketWebsite
• GetObject
• GetObjectAcl
• GetObjectAttributes
• GetObjectLegalHold
• GetObjectLockConfiguration
• GetObjectRetention
• GetObjectTagging
• GetPublicAccessBlock
• HeadBucket
• HeadObject
• ListBucketAnalyticsConfigurations
• ListBucketIntelligentTieringConfigurations
• ListBucketInventoryConfigurations
• ListBucketMetricsConfigurations
• ListBuckets
• ListDirectoryBuckets
• ListMultipartUploads
• ListObjectVersions
• ListObjects
• ListObjectsV2
• ListParts
• PutBucketAbac
• PutBucketAccelerateConfiguration
• PutBucketAcl
• PutBucketAnalyticsConfiguration
• PutBucketCors
• PutBucketEncryption
• PutBucketIntelligentTieringConfiguration
• PutBucketInventoryConfiguration
• PutBucketLifecycleConfiguration
• PutBucketLogging
• PutBucketMetricsConfiguration
• PutBucketNotificationConfiguration
• PutBucketOwnershipControls
• PutBucketPolicy
• PutBucketReplication
• PutBucketRequestPayment
• PutBucketTagging
• PutBucketVersioning
• PutBucketWebsite
• PutObject
• PutObjectAcl
• PutObjectLegalHold
• PutObjectLockConfiguration
• PutObjectRetention
• PutObjectTagging
• PutPublicAccessBlock
• RenameObject
• SelectObjectContent
• UpdateBucketMetadataInventoryTableConfiguration
• UpdateBucketMetadataJournalTableConfiguration
• UpdateObjectEncryption
• UploadPart
• UploadPartCopy
• WriteGetObjectResponse

Stubbed APIs (4) — routed but return an empty/default response

• CreateSession
• GetBucketPolicyStatus
• GetObjectTorrent
• RestoreObject

Path-style bucket URLs

winterbaume only supports path-style S3 URLs (http://host:port/bucket/key). Virtual-hosted-style URLs (http://bucket.host:port/key) are not supported when using a custom endpoint.

Most AWS SDKs and tools default to virtual-hosted-style for S3. When pointing them at winterbaume, you need to force path-style addressing. For example:

• AWS CLI: aws s3api --endpoint-url http://localhost:5555 list-buckets (path-style is the default for custom endpoints)
• aws-sdk-rust: use force_path_style(true) on the S3 config builder
• Terraform: set s3_use_path_style = true in the provider block:

provider "aws" {
  region                      = "us-east-1"
  access_key                  = "test"
  secret_key                  = "test"
  s3_use_path_style           = true
  skip_credentials_validation = true
  skip_metadata_api_check     = true
  skip_requesting_account_id  = true

  endpoints {
    s3  = "http://localhost:5555"
    sts = "http://localhost:5555"
  }
}