Go Rest API Project

This is a Go project created with Echo V4, Viper, Gorm, etc. This could be used as a foundational project. This project comes with pre-configured observability stack based on LGTM stack by Grafana and is instrumented with Opentelemetry SDK

Technologies used

• Echo v4 - API Framework
• Viper - Configuration Management
• Opentelemetry - Observability library
• Grafana Tempo - For trace visualisation
• Grafana Loki - Log backend
• Fluentbit - Log forwarder

How to run the project

The docker-compose.yml file provided with this project includes everything to setup and run the projects. Issue the command on the terminal to launch the project

docker compose up -d --build

Convention

Since this is an opinionated project, I lay down the foundation based on my own use case

Project Structure

The project is based on simple configuration of 3-tier architecture with the following main directories serving each layer

• Presentation Layer is represented as api directory
• Business Layer (Domain Layer) is represented as services directory
• The Data Access Layer is represented as models directory holding ORM specific files e.g. GORM definitions or MongoDB models

These directories rest inside the internal directory

Shared packages

The shared packages are all located in the pkg directory. This directory does not store business specific code, only shared modules e.g. response objects, utility functions, error codes, etc.

Configuration Management

For local development, the file config.yaml will be used to store local configuration. This file is not meant to be committed into the version control software

Config unmarshalling

The main configuration object is config/config.go where all configurations (both from YAML and environment variables) are unmarshalled into. Thus, whenever the new configuration is added to the YAML file, you can add it to the config/config.go

How to override the configuration with environment variables

To override nested configuration like

otlp:
  endpoint: localhost:4317

Use the convention of <PARENT>_<CHILD> (underscore_delimited)

For example, to override the above YAML for Opentelemetry endpoint. Use below environment variable format

OTLP_ENDPOINT=localhost:4317