Engine Gateway

Engine Gateway is a lightweight orchestration layer that makes it easy to mount, compose, and run multiple FastAPI applications as a distributed service for easier deployment. It dynamically loads app modules based on configuration and exposes them under configurable subpaths — enabling modular service composition, clean boundaries between components, and centralized deployment.

Usage

Installation

pip install dsw-engine-gateway
# or specific version
pip install dsw-engine-gateway==0.1.0
# or from repository
pip install git+https://github.com/ds-wizard/engine-gateway.git#egg=engine-gateway

Configuration

Create a configuration file (e.g., config.yaml) to define the applications to be mounted:

mounts:
  /example1:
    module: example_app
    app: app
  /example2:
    module: another_app.app
    factory: create_app
    kwargs:
      debug: true

Naturally, the module should be importable in your Python environment (i.e. having installed Python package exporting that module). You can specify either an app variable (a FastAPI instance) or a factory function that returns a FastAPI instance. Additional keyword arguments can be passed to the factory function via kwargs.

If hosting on different subpath than root, you can configure the base path of the gateway:

gateway:
  root_path: /gateway

You can also configure /info endpoint that reports metadata about the mounted applications:

gateway:
  info:
    enabled: true
    token: secretToken

(See config.example.yaml for more details.)

You can also use the following environment variables to override configuration options:

• CONFIG_FILE: Path to the configuration file (default: config.yaml).
• GATEWAY_ROOT_PATH: Base path for the gateway (overrides gateway.root_path).
• GATEWAY_INFO_ENABLED: Enable or disable the /info endpoint (overrides gateway.info.enabled).
• GATEWAY_INFO_TOKEN: Token for accessing the /info endpoint (overrides gateway.info.token).
• SENTRY_DSN: DSN for Sentry error tracking (enables Sentry integration if set).
• SENTRY_TRACES_SAMPLE_RATE: Sample rate for Sentry performance tracing (default: 1.0).
• SENTRY_PROFILES_SAMPLE_RATE: Sample rate for Sentry profiling (default: 1.0).
• SENTRY_MAX_BREADCRUMBS: Maximum number of breadcrumbs to store in Sentry (default: 100).
• SENTRY_ENVIRONMENT: Environment name for Sentry (default: production).
• SENTRY_AWS_LAMBDA: Enable AWS Lambda integration for Sentry (default: false).

Usage

You can run the Engine Gateway using Uvicorn:

uvicorn engine_gateway:create_app --host

In typical use cases, you would use engine_gateway as a dependency and re-packing it together with your config files and environment setup into a Docker image for deployment:

FROM dsw-engine-gateway:latest

COPY requirements.txt /app/requirements.txt
RUN pip install -r /app/requirements.txt

COPY config.yaml /app/config.yaml

CMD ["uvicorn", "engine_gateway:create_app", "--host", "0.0.0.0", "--port", "80", "--proxy-headers"]

License

This project is licensed under the Apache-2.0 License. See the LICENSE file for details.