Demo Microservices

Project implements ingredients for your startup named <Insert_Element_Here>BNB, but beware that Air is taken already!

This repository represents a showcase of microservices written in Go language.

The repository was created in April 2021 (using Go 1.16) and updated in March 2023 (using Go 1.20).

Yes, it's highly over-engineered with the purpose of showcasing the "how to" different techniques and conventions.

Setup

I'm using Linux. For other operating systems, you have to figure out the potential problems you might have.

Prerequisites

docker and docker-compose - no instructions here.

protoc - I've used version 3.12.3 (you can check your version with apt list -a protobuf-compiler) - (to install, run sudo apt install -y protobuf-compiler)

swag - to install, run go install github.com/swaggo/swag/cmd/swag@v1.8.10

migrate - to install run go install -tags 'postgres' github.com/golang-migrate/migrate/v4/cmd/migrate@v4.15.2

Note : you can install swag and migrate if needed by running make install_swag_and_migrate (NOT inside this repo)

Steps

DockerCompose

• run dependencies locally docker-compose -f docker-compose.local.yml up

• (later) to stop containers gracefully use (so you can start them) docker-compose -f docker-compose.local.yml stop

• (later) ... then pick up where you stopped the containers docker-compose -f docker-compose.local.yml start

• (later) to delete containers docker-compose -f docker-compose.local.yml down

Containers

The following containers will get started : postgis_images_container - this is the postgresql database for images microservice
postgis_comments_container - this is the postgresql database for comments microservice
postgis_users_container - this is the postgresql database for users microservice
postgis_hotels_container - this is the postgresql database for hotels microservice

redis_users - this is the redis container,

node_exporter_container -

microservices-demo_rabbitmq_1 - this is the rabbitmq container, navigate to http://localhost:15672 for the UI. Use guest for both user and password. grafana_container - grafana container, navigate to http://localhost:3000 for the beautiful UI. Use admin for both password and user.
prometheus_container - prometheus container, navigate to http://localhost:9090 for the UI.
jaeger_container - jaeger container, navigate to http://localhost:16686 to see the UI. minio_aws_container -

TODO : add adminer

Initial Database Setup using Make

• migrate all databases make init_databases

Generate Swagger

run: make swagger_api

Swagger UI:

• https://localhost:8081/swagger/index.html (note this is a HTTPS route - see certificate troubleshooting)

Note : navigate to chrome://flags/#allow-insecure-localhost and set it to enabled to get rid of the warning.

Packages choices

1. Uber Zap for logging, because I consider it to be flexible and well written. By flexible, I understand that it can log to Kafka if you want to.
2. Echo

Interfaces (in Go) Design Principles:

1. Define the interface where it is being used
2. Expand request fields to make Service / Repository interface methods more readable and independent of transport layer
3. GRPC client should be passed as factory functions (which returns the actual interface of the client)