Page Comparison

This guide introduces the codebase app structure and deployment environments to new LiteFarm contributors.

The LiteFarm monorepo defines two packages: webapp and api. As we will see, there is a kind of a third package, embedded within the api folder, that provides a certification export service, variously known as "exports", "scheduler", or "job scheduler".

The webapp package

We use React as our primary frontend library. If you haven't seen React before we strongly recommend you go through the React Documentation and the tutorial. They are both extremely helpful getting started sources.

We use Redux for state management. If you haven't heard about Redux before, we strongly recommend you study the materials on their site. Or if you are more of a visual learner, Redux creator Dan Abramov has a free tutorial.

The api package

The API uses Node along with Express to run the backend and routing logic. You will need to be pretty familiar with Express routing before getting into any code.

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We use ObjectionJS to define the models in api/src/models.

The exports “package”

Within the api folder, the file packages/api/src/jobs/index.js defines is the entry point for a Node service that is run separately, as if it were a third package. This service monitors Redis-based work queues to receive and process requests for exports of certification information.

Deployments

Each of the three packages is deployed to the LiteFarm production environment, and to a pre-production environment generally known as “beta” (though it is not used for traditional beta testing).

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• litefarmapp, a Digital Ocean Droplet that:

  • runs the webapp package (behind an Nginx reverse proxy) in litefarm-web, a Docker container assigned the hostname app.litefarm.org

  • runs the api package in litefarm-api, a Docker container assigned the hostname api.app.litefarm.org

  • runs PostgreSQL in a Docker container named litefarm-db

  • provides file storage for the database contents and backups

• litefarm-imaginary, a Digital Ocean Droplet that:

  • provides file storage for ? images

  • runs the “exports package” jobs scheduler Node service

  • runs the Redis-based work queues used by the API server to submit export jobs to the scheduler

  • runs the image manipulation microservice imaginary in a Docker container

  • runs an Nginx web server, hostname image.litefarm.org, that :

  • serves images ….?

  reverse proxies access to a Docker container running the image manipulation microservice imaginary

• Object storage “buckets” (Digital Ocean Spaces (object storage “buckets”) that provide storage for …) that store images and documents uploaded by users, as well as certification exports for users to download.

The pre-production environment consists of:

• liteformbeta, a Droplet that duplicates the services on litefarmapp, with hostnames beta.litefarm.org and api.beta.litefarm.org

• export-beta, a Droplet that duplicates the services of on litefarm-imaginary, with one exception 🗒

• Digital Ocean Spaces (object storage “buckets”) that provide storage for …Buckets that duplicate those in the production environment.

Individual developers run local instances of the the litefarm-web, litefarm-api, and litefarm-db Docker containers. There are buckets …dedicated to object storage for development setups.

🗒 All deployments-- production, pre-production, and individual developers-- use the single instance of the imaginary microservice on image.litefarm.org