adobe/S3Mock

S3Mock is a mock implementation of the AWS S3 API that runs as a Docker image, TestContainer, JUnit Jupiter extension, or TestNG listener.

S3Mock addresses the need to test S3-dependent code without provisioning real AWS infrastructure. It implements a subset of the Amazon S3 API, allowing developers to run integration tests locally. The tool can be deployed as a Docker container, embedded in tests via Testcontainers, or integrated directly into test frameworks through JUnit 5 extensions or TestNG listeners. The README recommends Docker or Testcontainers usage to avoid classpath conflicts.

Teams should adopt S3Mock for local integration testing during development and in CI/CD pipelines where spinning up real S3 buckets is impractical or costly. It suits projects that need fast feedback loops and isolated test environments. The tool is particularly valuable for teams already using Docker or Testcontainers, as these are the recommended deployment methods. Projects requiring only a subset of S3 operations will find it sufficient; the README documents which operations are supported, so teams should verify coverage against their specific use cases before adoption.

The project maintains active development with regular updates to align with modern Java and Spring Boot versions. Migration paths are documented for major version transitions, including filesystem structure changes and dependency updates. The codebase has undergone significant modernization, including removal of legacy AWS SDK v1 support, JUnit 4 support, and Apache Commons dependencies in favor of Kotlin and Java standard library equivalents. Configuration has been refactored with new environment variables and properties replacing deprecated legacy options.