gqlmeetup

This is an example graphql server built using gqlgen. It features:

• PostgreSQL backend using sqlx
• Dataloaders using dataloaden
• Tests
• Session-based authentication and authorization

Architecture

This project mostly follows Ben Johnson's standard package layout. The domain types and interfaces are defined in the root package (gqlmeetup.go). The subpackages provide implementations of the interfaces defined by the root package.

bcrypt

This subpackage wraps the standard library bcrypt package and provides methods for checking and hashing user passwords. It provides an implementation of the PasswordService interface.

cmd

cmd subpackage holds the executables:

• server - runs the GraphQL server
• createuser - a simple helper tool to create users

dataloaden

This is where the dataloader code is located. Much of the code is generated using the dataloaden tool. The subpackage provides an implmentation of the DataLoaderService interface and it depends on the Repository interface for all database-related functionality. The Middleware method is a HTTP middleware which must be used to wrap the GraphQL handler using the dataloader service.

gqlgen

This subpackage holds the code generated by gqlgen along with custom resolver definitions, directives logic and some helper functions for initializing the handlers used by the HTTP server. This subpackage has the following dependencies:

• Repository which provides the resolvers with database functionality;
• DataLoaderService which provides the resolvers with dataloader functionality (for optimizing relational queries and avoiding the n+1 query problem);
• PasswordService which gives resolvers the ability to check and hash passwords;
• SessionService which provides functionality for managing user sessions (login/logout).

http

This subpackage implements a simple HTTP server that used by the GraphQL server. The package depends on SessionService and DataLoaderService interface implementations as the server needs to be able to initialize the dataloaders and work with user session on incoming requests.

scs

This subpackage wraps the scs package and provides the functionality related to user authentication and authorization.. It provides an implementation of the SessionService interface.

mocks

Mock versions of the root package interfaces which are used for testing. The mocks are automatically generated using moq.

postgres

This package provides the database-related functionality to the resolvers, dataloaders and createuser executable via its implementation of the Repository interface. I'm using the wonderful sqlx along with some custom helper functions to make working with PostgreSQL easier.