Working with Microservices in Go

This is the source code for the Udemy course Working with Microservices and Go. This project consists of a number of loosely coupled microservices, all written in Go:

• broker-service: an optional single entry point to connect to all services from one place (accepts JSON; sends JSON, makes calls via gRPC, and pushes to RabbitMQ)
• authentication-service: authenticates users against a Postgres database (accepts JSON)
• logger-service: logs important events to a MongoDB database (accepts RPC, gRPC, and JSON)
• queue-listener-service: consumes messages from amqp (RabbitMQ) and initiates actions based on payload (sends via RPC)
• mail-service: sends email (accepts JSON)

All services (except the broker) register their access urls with etcd, and renew their leases automatically. This allows us to implement a simple service discovery system, where all service URLs are accessible with "service maps" in the Config type used to share application configuration in the broker service.

In addition to the microservices, the included docker-compose.yml at the root level of the project starts the following services:

• Postgresql - used by the authentication service to store user accounts
• MongoDB - used by the logger service to save logs from all services
• etcd - used for service discovery
• mailhog - used as a fake mail server to work with the mail service

Running the project

From the root level of the project, execute this command (this assumes that you have GNU make and a recent version of Docker installed on your machine):

make up_build 

If the code has not changed, subsequent runs can just be make up.

Then start the front end:

make start

Hit the front end with your web browser at http://localhost:80. You can also access a web front end to the logger service by going to http://localhost:8082 (or whatever port you specify in the docker-compose.yml file).

To stop everything:

make stop
make down

While working on code, you can rebuild just the service you are working on by executing

make auth

Where auth is one of the services:

• auth
• broker
• logger
• listener
• mail

All make commands:

tcs@Grendel go-microservices % make help
Choose a command:
up starts all containers in the background without forcing build
down stop docker compose
build_auth builds the authentication binary as a linux executable
build_logger builds the logger binary as a linux executable
build_broker builds the broker binary as a linux executable
build_listener builds the listener binary as a linux executable
build_mail builds the mail binary as a linux executable
up_build stops docker-compose (if running), builds all projects and starts docker compose
auth stops authentication-service, removes docker image, builds service, and starts it
broker stops broker-service, removes docker image, builds service, and starts it
logger stops logger-service, removes docker image, builds service, and starts it
mail stops mail-service, removes docker image, builds service, and starts it
listener stops listener-service, removes docker image, builds service, and starts it
start starts the front end
stop stop the front end
test runs all tests
clean runs go clean and deletes binaries
help displays help