nodule-sample-gateway

Deprecated

⚠️ this repository (like the nodule- libraries) is now deprecated. ⛔

A sample gateway to showcase the nodule- libraries for making gateways in graphql.

Much like the charismatic pikachu the gateway ties together the rest of your team across frontend and backend.

Prerequisites

1. Make sure you have nvm installed. On mac:

    brew install nvm
   

2. Identify the version of Node.js to use.

   You can find this version in build.pikachu/docker-base/Dockerfile.deps. The version in this file represents the version we use in CircleCI and should be representative of what version the service is intended to run with..

3. Install Yarn with brew install yarn.

4. Make sure you're using python2 for pikachu.

It's a little crazy but some of the node deps of our gateways actually depend on python2 specifically. If you use virtualenvwrapper you can get python2 for pikachu with:

    mkvirtualenv pikachu --python=python2.7

5. Install the project dependencies with yarn instsall.

Structure

The code structure for pikachu aims to have small, consistent components that provide a unidirectional data flow:

• The config gets loaded first and used to initialize the app.
• The routes define HTTP entry points into the app. The graphql endpoint(s) live here.
• The resources define the GraphQL types used in the top-level graph schema
• The resolvers allow the resources to relate to each other within the graph schema.
• The resolvers use backend services to fetch and mutate resources.
• The services use a series of wrappers to implement batching, caching, and deduplication.

TBA

• The clients use OpenAPI (aka swagger) to communicate with the backends.

Guidelines

When adding to pikachu:

1. Write APIs with an eye towards what the frontend needs vs what the backend providers; pikachu is a translation layer!
2. Resources should be named singularly and contain a list-valued property (called items) for pagination.
3. Resolvers and services should use a consistent signature of (req, args) or (req, { some, value }).

Commands

The following CLI commands are available, via yarn (e.g yarn lint):

• lint: Runs airbnb flavored eslint
• local: Runs a non-transpiled local server using babel
• build: Runs tests and transpiles ES6 -> ES5
• start: Runs tests, build and serves transpiled JS
• test: Runs tests
• coverage: Runs tests and outputs coverage report

Running Locally

You will need to set a few environment variables for local development:

• Create your own local env file:

  cp .env.example .env
  # edit .env
  

• Source this configration:

  source .env
  

• Run the local server:

  yarn run local
  

• Connect to http://localhost:3002/gql/graphiql

Service clients TBA

We use swagger definitions defined in a central place to autogenerate service clients. Details TBA.