The authorization landscape for Rust applications has a new contender with Gatehouse, a flexible authorization library that's drawing attention from developers for its multi-paradigm approach and developer-friendly design. The library combines role-based (RBAC), attribute-based (ABAC), and relationship-based (ReBAC) access control policies, offering Rust developers a comprehensive toolkit for implementing authorization systems.
Gatehouse Core Features
- Multi-paradigm Authorization: Support for RBAC, ABAC, and ReBAC patterns
- Policy Composition: Combine policies with logical operators (AND, OR, NOT)
- Detailed Evaluation Tracing: Complete decision trace for debugging and auditing
- Fluent Builder API: Construct custom policies with a PolicyBuilder
- Type Safety: Strongly typed resources/actions/contexts
- Async Ready: Built with async/await support
Built-in Policies
RbacPolicy: Role-based access controlAbacPolicy: Attribute-based access controlRebacPolicy: Relationship-based access control
Async-First Design Sparks Discussion
Gatehouse's async-friendly architecture has become a focal point of community discussion. The library implements async functions for policy checking, which some developers have questioned given that many authorization checks don't inherently require I/O operations. The project's maintainer clarified that this design choice was deliberate to support scenarios like graph traversal in relationship-based authorization and to enable short-circuiting of expensive operations.
I wanted to support short circuiting such that somewhat expensive IO calls might be skipped by returning early from a policy that didn't need to make that call.
This approach provides flexibility for applications that might need to perform database lookups or service calls during authorization checks, while still allowing simpler in-memory policy evaluations. The design choice reflects a forward-thinking approach that allows developers to start with simpler authorization models and evolve to more complex ones without significant refactoring.
Comparison to DSL-Based Alternatives
Many developers in the comments compared Gatehouse to other authorization frameworks like Cedar, which use domain-specific languages (DSLs) for policy definition. While DSLs offer benefits like cross-language compatibility and the ability to store policies as data rather than code, some developers expressed appreciation for Gatehouse's native Rust approach.
The discussion highlighted an important trade-off: DSL-based systems provide greater flexibility for organizations that need to share policies across different programming languages or manage policies as data, while code-native approaches like Gatehouse offer tighter integration with the application and potentially simpler developer workflows for smaller projects.
The Data Access Challenge
A recurring theme in the community discussion was the dual-write problem and challenges around data access for authorization decisions. One commenter pointed out that policy engines alone aren't sufficient for comprehensive authorization systems - they also need access to the data required to make authorization decisions.
This highlights an important consideration for developers implementing Gatehouse: while the library provides flexible policy evaluation, applications still need to determine how to efficiently retrieve and provide the necessary data to the policy engine. Unlike some more opinionated frameworks, Gatehouse leaves this aspect to the application developer, following a bring your own persistence approach that some commenters specifically appreciated.
Code Organization Considerations
Some technical observations from the community focused on the library's code organization, with one commenter noting the large size of the main library file. This sparked a brief discussion about code organization practices in Rust, with the maintainer acknowledging that breaking up the large file would be beneficial. This kind of community feedback demonstrates the collaborative nature of open-source development and provides valuable input for future improvements.
In conclusion, Gatehouse represents a promising addition to the Rust ecosystem for developers seeking a flexible, native authorization solution. Its multi-paradigm approach and async-friendly design offer a solid foundation for implementing complex authorization systems, though developers will need to carefully consider how to integrate it with their data access patterns. As with many security-related libraries, the right choice depends heavily on specific project requirements and organizational constraints.
Reference: Gatehouse