Skip to content

Latest commit

 

History

History
359 lines (306 loc) · 17.6 KB

sec-design.md

File metadata and controls

359 lines (306 loc) · 17.6 KB

BUSINESS POSTURE

Locust is an open-source load testing tool. The business priorities likely revolve around:

  • Providing a reliable and scalable tool for developers and performance engineers.
  • Maintaining an active and engaged open-source community.
  • Ensuring the tool is easy to use and extend.
  • Supporting a wide range of use cases and protocols (though HTTP is the primary focus).
  • Keeping the codebase maintainable and well-documented.

Given that Locust is an open-source project, the business risks are somewhat different from a commercial product. Key risks include:

  • Loss of community interest and contributions.
  • Security vulnerabilities that could be exploited in user environments (since Locust executes user-provided code).
  • Lack of maintainability leading to stagnation.
  • Competition from other open-source or commercial load testing tools.
  • Reputational damage due to security issues or poor performance.
  • Inability to scale to meet the needs of large-scale load tests.

SECURITY POSTURE

  • security control: The project uses GitHub for code hosting, which provides some inherent security features like access control and audit logs. (Described in GitHub repository)
  • security control: The project appears to use linters (flake8) to enforce code style and potentially catch some basic errors. (Described in .github/workflows/tests.yml)
  • security control: The project has a suite of unit and integration tests. (Described in .github/workflows/tests.yml)
  • security control: The project uses a continuous integration (CI) system (GitHub Actions) to automate testing. (Described in .github/workflows/tests.yml)
  • accepted risk: Locust executes arbitrary Python code provided by the user. This is inherent to its design and is a known, accepted risk. Users are responsible for the security of the code they execute within Locust.
  • accepted risk: Locust, by default, doesn't enforce secure communication (HTTPS) between the master and worker nodes. This is left to the user's configuration and deployment environment.
  • accepted risk: Locust's web UI does not enforce authentication by default.

Recommended Security Controls:

  • security control: Implement a Content Security Policy (CSP) for the web UI to mitigate XSS risks.
  • security control: Provide clear documentation and warnings about the security implications of running user-provided code.
  • security control: Offer options/guidance for securing communication between master and worker nodes (e.g., using TLS).
  • security control: Offer built-in authentication mechanisms for the web UI, or provide clear instructions for integrating with existing authentication systems.
  • security control: Regularly perform static analysis (SAST) and dependency vulnerability scanning as part of the CI/CD pipeline.
  • security control: Consider implementing a Software Bill of Materials (SBOM) for releases.
  • security control: Develop and publish a security policy outlining vulnerability reporting procedures.

Security Requirements:

  • Authentication:
    • The web UI should offer optional authentication mechanisms to restrict access.
    • Consider supporting common authentication protocols (e.g., OAuth 2.0, OpenID Connect).
  • Authorization:
    • If authentication is implemented, authorization should control access to specific features and data within the web UI.
    • Consider role-based access control (RBAC).
  • Input Validation:
    • All user-provided input in the web UI and through configuration files should be validated to prevent injection attacks.
    • User-provided Locust scripts (Python code) are inherently trusted, but the framework should provide mechanisms to help users write secure code (e.g., input sanitization libraries).
  • Cryptography:
    • Communication between master and worker nodes should be encrypted using TLS if sensitive data is being transmitted or if the environment is untrusted.
    • Sensitive data stored by Locust (if any) should be encrypted at rest.
  • Session Management:
    • If authentication is implemented, secure session management practices should be followed (e.g., using secure, HTTP-only cookies, proper session timeouts).

DESIGN

C4 CONTEXT

graph LR
    User["User (Developer/Tester)"] -- "Uses" --> Locust["Locust Load Testing Tool"]
    Locust -- "Simulates traffic to" --> TargetSystem["Target System Under Test"]
    Locust -- "Reports to" --> ReportingSystem["Reporting System (Optional)"]
Loading
  • Elements:

    • Element:

      • Name: User (Developer/Tester)
      • Type: Person
      • Description: The person who writes and runs Locust tests.
      • Responsibilities:
        • Writes Locust scripts (Python code) defining user behavior.
        • Configures and runs Locust tests.
        • Analyzes test results.
      • Security controls:
        • None directly implemented by Locust. Users are responsible for the security of their own systems and the code they write.

    • Element:

      • Name: Locust Load Testing Tool
      • Type: Software System
      • Description: The open-source load testing tool itself.
      • Responsibilities:
        • Executes user-defined load tests.
        • Simulates virtual users.
        • Collects and reports performance metrics.
        • Provides a web UI for monitoring and control.
      • Security controls:
        • Limited built-in security controls. Relies on user-provided code and deployment environment for security.

    • Element:

      • Name: Target System Under Test
      • Type: Software System
      • Description: The system being load tested. This is external to Locust.
      • Responsibilities:
        • Receives and responds to requests generated by Locust.
      • Security controls:
        • Not controlled by Locust. The target system's security is the responsibility of its owners.

    • Element:

      • Name: Reporting System (Optional)
      • Type: Software System
      • Description: An external system to which Locust can send test results (e.g., a time-series database like Graphite or Prometheus).
      • Responsibilities:
        • Stores and visualizes Locust test results.
      • Security controls:
        • Not controlled by Locust. The reporting system's security is the responsibility of its owners.

C4 CONTAINER

graph LR
    User["User (Developer/Tester)"] -- "Uses (HTTP/HTTPS)" --> WebUI["Web UI (Flask)"]
    User -- "Writes and runs (Python)" --> Locustfile["Locustfile (Python Code)"]
    WebUI -- "Controls (RPC)" --> Master["Master Process"]
    Master -- "Manages (RPC)" --> Worker["Worker Process(es)"]
    Worker -- "Simulates traffic (Various Protocols)" --> TargetSystem["Target System Under Test"]
    Master -- "Reports (Various Protocols)" --> ReportingSystem["Reporting System (Optional)"]
    Locustfile -.-> Master
    Locustfile -.-> Worker
Loading
  • Elements:

    • Element:

      • Name: Web UI (Flask)
      • Type: Web Application
      • Description: A web-based user interface built using the Flask framework.
      • Responsibilities:
        • Provides a user interface for controlling and monitoring load tests.
        • Displays real-time statistics.
        • Allows starting, stopping, and configuring tests.
      • Security controls:
        • Recommended: CSP, authentication, authorization.

    • Element:

      • Name: Locustfile (Python Code)
      • Type: Code
      • Description: User-written Python code that defines the load test scenario.
      • Responsibilities:
        • Defines user behavior (tasks to be executed).
        • Specifies the number of users, hatch rate, etc.
      • Security controls:
        • None directly implemented by Locust. Users are responsible for the security of their code.

    • Element:

      • Name: Master Process
      • Type: Process
      • Description: The main Locust process that coordinates the load test.
      • Responsibilities:
        • Manages worker processes.
        • Aggregates statistics.
        • Handles communication with the web UI.
      • Security controls:
        • Recommended: Secure communication (TLS) with worker processes.

    • Element:

      • Name: Worker Process(es)
      • Type: Process
      • Description: One or more worker processes that simulate users.
      • Responsibilities:
        • Executes tasks defined in the Locustfile.
        • Sends requests to the target system.
        • Reports statistics to the master process.
      • Security controls:
        • Recommended: Secure communication (TLS) with the master process.

    • Element:

      • Name: Target System Under Test
      • Type: Software System
      • Description: The system being load tested (external to Locust).
      • Responsibilities:
        • Receives and responds to requests from Locust worker processes.
      • Security controls:
        • Not controlled by Locust.

    • Element:

      • Name: Reporting System (Optional)
      • Type: Software System
      • Description: An external system for storing and visualizing test results.
      • Responsibilities:
        • Receives and stores data from the Locust master process.
      • Security controls:
        • Not controlled by Locust.

DEPLOYMENT

Locust can be deployed in various ways:

  1. Local Machine: Running Locust directly on a developer's machine.
  2. Dedicated Servers: Deploying Locust master and worker processes on dedicated servers (physical or virtual).
  3. Docker Containers: Running Locust master and worker processes within Docker containers.
  4. Kubernetes: Deploying Locust as a distributed system within a Kubernetes cluster.

We'll describe the Kubernetes deployment in detail, as it's the most complex and scalable option.

graph LR
    subgraph Kubernetes Cluster
        subgraph Namespace [Locust Namespace]
            MasterPod["Master Pod"] -- "RPC" --> WorkerPod1["Worker Pod 1"]
            MasterPod -- "RPC" --> WorkerPodN["Worker Pod N"]
            MasterService["Master Service (ClusterIP)"] -- "Exposes" --> MasterPod
            WorkerService["Worker Service (ClusterIP)"] -- "Exposes" --> WorkerPod1
            WorkerService -- "Exposes" --> WorkerPodN
            WebUIIngress["Ingress"] -- "HTTP/HTTPS" --> MasterService
        end
    end
    User["User (Developer/Tester)"] -- "Accesses (HTTP/HTTPS)" --> WebUIIngress
    WorkerPod1 -- "Simulates traffic" --> TargetSystem["Target System Under Test"]
    WorkerPodN -- "Simulates traffic" --> TargetSystem
Loading
  • Elements:

    • Element:

      • Name: Kubernetes Cluster
      • Type: Infrastructure
      • Description: The Kubernetes cluster where Locust is deployed.
      • Responsibilities:
        • Provides the infrastructure for running and managing Locust containers.
      • Security controls:
        • Kubernetes RBAC, network policies, pod security policies, etc.

    • Element:

      • Name: Locust Namespace
      • Type: Logical Isolation
      • Description: A Kubernetes namespace to isolate Locust resources.
      • Responsibilities:
        • Provides a logical grouping for Locust pods and services.
      • Security controls:
        • Kubernetes namespace-level security policies.

    • Element:

      • Name: Master Pod
      • Type: Pod
      • Description: A Kubernetes pod running the Locust master process.
      • Responsibilities:
        • Runs the Locust master process.
      • Security controls:
        • Kubernetes pod security context, network policies.

    • Element:

      • Name: Worker Pod 1, Worker Pod N
      • Type: Pod
      • Description: Kubernetes pods running Locust worker processes.
      • Responsibilities:
        • Runs Locust worker processes.
      • Security controls:
        • Kubernetes pod security context, network policies.

    • Element:

      • Name: Master Service (ClusterIP)
      • Type: Service
      • Description: A Kubernetes service that exposes the master pod within the cluster.
      • Responsibilities:
        • Provides a stable endpoint for worker pods to connect to the master.
      • Security controls:
        • Kubernetes service-level network policies.

    • Element:

      • Name: Worker Service (ClusterIP)
      • Type: Service
      • Description: A Kubernetes service that exposes the worker pods within the cluster.
      • Responsibilities:
        • Provides load balancing across worker pods.
      • Security controls:
        • Kubernetes service-level network policies.

    • Element:

      • Name: Ingress
      • Type: Ingress
      • Description: A Kubernetes Ingress that exposes the web UI to external users.
      • Responsibilities:
        • Provides external access to the Locust web UI.
      • Security controls:
        • Ingress-level security policies (e.g., TLS termination, authentication).

    • Element:

      • Name: User (Developer/Tester)
      • Type: Person
      • Description: The person accessing the Locust web UI.
      • Responsibilities:
        • Interacts with the Locust web UI.
      • Security controls:
        • None directly implemented by Locust.

    • Element:

      • Name: Target System Under Test
      • Type: Software System
      • Description: The system being load tested.
      • Responsibilities:
        • Receives traffic from Locust worker pods.
      • Security controls:
        • Not controlled by Locust.

BUILD

Locust's build process is primarily managed through GitHub Actions, as defined in .github/workflows/tests.yml.

graph LR
    Developer["Developer"] -- "Pushes code" --> GitHubRepo["GitHub Repository"]
    GitHubRepo -- "Triggers" --> GitHubActions["GitHub Actions"]
    GitHubActions -- "Runs linters (flake8)" --> Linting["Linting"]
    GitHubActions -- "Runs tests" --> Tests["Tests (pytest)"]
    Linting -- "Reports results" --> BuildResult["Build Result"]
    Tests -- "Reports results" --> BuildResult
    GitHubActions -- "Builds package" --> Package["Package (Wheel/sdist)"]
    Package -- "Published to" --> PyPI["PyPI (Python Package Index)"]
Loading
  • The build process is triggered by pushes to the repository.
  • GitHub Actions runs linters (flake8) to check code style.
  • GitHub Actions runs tests using pytest.
  • The build process creates Python packages (wheel and sdist).
  • Packages are typically published to PyPI (Python Package Index).

Security Controls:

  • security control: Linting (flake8) helps enforce code style and potentially catch some errors.
  • security control: Automated tests (pytest) help ensure code quality and prevent regressions.
  • security control: GitHub Actions provides a controlled and auditable build environment.

Recommended Security Controls:

  • security control: Integrate SAST tools (e.g., Bandit, Snyk) into the GitHub Actions workflow to scan for security vulnerabilities in the code.
  • security control: Integrate dependency scanning tools (e.g., pip-audit, Dependabot) to identify and update vulnerable dependencies.
  • security control: Sign releases uploaded to PyPI to ensure their integrity.
  • security control: Implement SBOM generation as part of the build process.

RISK ASSESSMENT

  • Critical Business Processes:
    • Providing a functional and reliable load testing tool.
    • Maintaining an active open-source community.
  • Data to Protect:
    • Locust itself doesn't handle highly sensitive data directly. The primary concern is the user-provided Locust scripts and the target system's data.
    • User-provided scripts might contain credentials or other sensitive information for interacting with the target system. (Sensitivity: Potentially High, depending on the user's code)
    • The target system's data is accessed by Locust, but not stored by Locust. (Sensitivity: Depends entirely on the target system)
    • Test results (performance metrics) are generated by Locust, but these are generally not considered highly sensitive. (Sensitivity: Low)
    • Locust Web UI access credentials (if authentication is enabled). (Sensitivity: Medium)

QUESTIONS & ASSUMPTIONS

  • Questions:

    • Are there any specific compliance requirements (e.g., GDPR, PCI DSS) that apply to the use of Locust or the systems being tested?
    • What is the expected scale of Locust deployments (number of users, requests per second)?
    • What are the specific security concerns of the users of Locust?
    • What level of support is provided for securing communication between master and worker nodes?
    • Is there a formal process for handling security vulnerabilities reported in Locust?

  • Assumptions:

    • Users are responsible for the security of their Locust scripts and the target systems they test.
    • The primary threat model involves malicious or poorly written user scripts, and vulnerabilities in the Locust framework itself.
    • The deployment environment (e.g., Kubernetes cluster) is configured securely.
    • Users are aware of the risks associated with running unauthenticated web UIs and unencrypted communication.
    • The project prioritizes maintainability and community contributions.
    • The project has limited resources for implementing complex security features.