As applications grow, managing user permissions becomes more complex. Role-Based Access Control (RBAC) addresses this by assigning users predefined roles that group permissions together. In Python, you can implement RBAC using custom solutions or third-party libraries like Oso. These tools enable consistent enforcement of role-based access across your application. This guide explores what RBAC is, the challenges of RBAC implementation and how solutions like Oso assist in defining and managing roles and permissions in Python applications.
What is Role-Based Access Control (RBAC) in Python?
Roles are a common way to simplify authorization logic for engineers and users. Authorization logic that’s based on roles is called “role-based access control.”
A role is a way to group permissions. When a user is assigned a role, the user gets every permission that the role has.
A permission is an action that a user can take on a resource. For example, we might say that a user in an organization has permission to read repositories.
There are a number of variations on role-based access to allow for more flexible groupings of permissions, like:
To implement RBAC in Python, you can use either built-in logic or third-party libraries
Built-in logic approaches:
- Using Python classes – Create a
Roleclass and aUserclass to manage roles and permissions. - RBAC with JSON for configurable roles – Store roles and permissions in a JSON file, allowing dynamic updates without modifying the code.
- RBAC with a SQL database – Store roles and permissions in an SQL database for easy querying.
- RBAC with environment variables – Configure permissions dynamically in serverless functions or cloud environments.
Third-party libraries:
- Flask-Principal – For managing RBAC in Flask applications.
- Oso – A declarative authorization framework.
Why Use RBAC in Python?
RBAC in Python centralizes permission management by assigning roles to users instead of handling individual permissions. This approach reduces complexity and ensures consistent access control.
Key Benefits of implementing RBAC in Python:
- Groups permissions into roles, simplifying authorization logic.
- Enforces the principle of least privilege by restricting access based on roles.
- Supports large user bases by structuring access control at different levels.
- Integrates with databases and frameworks like Django, FastAPI, and Flask.
- Works alongside models like ABAC or ReBAC for fine-grained access control.
- Helps meet compliance requirements for standards like GDPR and HIPAA.
Python’s libraries and frameworks provide tools for implementing RBAC with structured policies and data management.
Oso Cloud is an authorization service for building RBAC in Python
Oso’s Python SDK provides tools for defining and enforcing RBAC policies. It supports declarative policy definitions and integrates with existing applications. Oso can be used for new implementations or to enhance existing authorization systems.
For detailed implementation guidance, refer to the Python SDK documentation.
4 reasons to build RBAC in Python with Oso:
- Oso Cloud is fully managed and deployed across multiple regions for low latency and high availability.
- Oso Cloud comes out of the box with primitives for role-based access control (RBAC). It also includes built-ins for other access control models like relationship-based access control (ReBAC) or attribute-based access control (ABAC).
- You provide Oso Cloud with the requisite authorization data, then your RBAC policy operates that data to make authorization decisions at runtime.
- Oso can provide yes/no authorization decisions, as well as filter lists of data.
Express RBAC in Python with Oso Cloud
To authorize whether a user has the role required to perform an action on a resource, call Oso in your controller.
# This will return `False` if the current user does not
# have access to the Repository that they're trying to read
user = Value("User", User.get_current_user())
repo = Value("Repository", repo_name)
oso.authorize(user, "read", repo)
You’ll also write an Oso policy—that is, a set of rules—to implement role-based authorization. Here, we’ll show a policy for an app for source code hosting like GitHub or GitLab.
In this policy, users may or may not be able to read or make changes to a repository, depending on whether they’re members or owners. That means we need authorization based on users’ roles.
actor User {}
resource Organization {
roles = ["owner"];
}
resource Repository {
permissions = ["read", "push"];
roles = ["contributor", "maintainer"];
relations = { parent: Organization };
# An actor has the "read" permission if they have the "contributor" role.
"read" if "contributor";
# An actor has the "push" permission if they have the "maintainer" role.
"push" if "maintainer";
# An actor has the "contributor" role if they have the "maintainer" role.
"contributor" if "maintainer";
# An actor has the "maintainer" role if they have the "owner" role on the
# "parent" Organization.
"maintainer" if "owner" on "parent";
}
To learn how to model RBAC with Oso, take a look at our RBAC modeling guide.
For a guide on other authorization models, such as ReBAC or ABAC, check out our authorization modeling guide covering roles, hierarchies, groups, and other patterns.
Filter data based on a user’s role
Your app needs to be able to return all the repos that a user can see based on their role and any other relevant criteria. To do this we can use the list method.
Here's that in the Python app again:
user = Value("User", User.get_current_user())
repos = oso.list(user, "read", "Repository")
Learn more about RBAC concepts, architecture, and best practices
We've written Authorization Academy to help you get started with RBAC and other authorization topics. The guide is language and technology-agnostic and covers industry-standard authorization concepts. Learn:
- How to architect your app for RBAC.
- Common access control models like role-based access control (RBAC) and relationship-based access control (ReBAC) – when to use them and how to implement them.
- Where to enforce authorization at various layers in your app.
Python RBAC FAQ
What are the challenges of implementing RBAC in Python?
Building an RBAC system from scratch in Python involves:
- Defining and managing roles and permissions.
- Scaling as the number of users increases.
- Integrating with authentication systems and APIs.
Using an authorization software like Oso addresses these challenges by providing a pre-built system that integrates into Python applications.
Should you build your own RBAC solution or use an existing framework like Oso?
Building an RBAC system in-house requires significant time and maintenance. Tools like Oso reduce engineering effort by providing a ready-to-use authorization framework. You can read more on this topic in our blog post "Build or Buy".
Can Oso be used with popular Python frameworks like Flask or FastAPI?
Yes, Oso integrates with Flask and FastAPI using its Python SDK, allowing role-based permissions to be enforced within existing application structures. The Oso SDK provides web framework middleware for oso-cloud, the Oso Cloud Client for Python. You can install it by running:
pip install oso-sdk
How do I get started with RBAC in Python using Oso?
- Install the Oso library:
pip install oso-cloud - Define roles and permissions in a policy file using Oso’s declarative syntax.
- Embed Oso in your application to enforce these permissions.
For detailed implementation steps, refer to Oso’s official documentation.
To conclude
Join the community of thousands of developers in the Oso Slack (including many Pythonistas!) and feel free to set up a 1x1 with an Oso engineer to learn more about RBAC in Python, Oso Cloud, or just authorization in general. We'd love to talk about what you're working on and answer any questions you have.