Compose

docker-compose deployment of microservices based document management service.

Services

There are two main services in the system, Gateway and Storage. The services built built with Golang by using Rabbitmq and Protobuf. Gateway service act as microservices api-gateway. Storage service do actual document management functions(ex: create documents in database). Protobuf use to serialized structured data(request response between microservices). Rabbitmq uses as message broker.

Client submit JSON documents to gateway service via REST api. Gateway service create Protobuf message based on the JSON data and pass it to storage service via Rabbitmq. Then storage service do what ever the operation(ex: create documents on a database) and sends the status back to gateway service as Protobuf message. Finally gateway service convert Protobuf message which receives from storage service into JSON object and send it back to client. Gateway service listen to Rabbitmq gateway queue and Storage service listen to storage queue.

Compile protobuf

# install protoc
brew install protobuf

# install go protobuf
go get github.com/golang/protobuf
go get github.com/golang/protobuf/protoc-gen-go

# complie protobuf
protoc spec/*.proto --go_out=:$GOPATH/src

Deploy services

Change host.docker.local field in .env file to local machines ip or add a host entry to /etc/hosts file by overriding host.docker.local with local machines ip. In mac-os host.docker.local will route to localhost, so nothing to change no mac-os.

docker-compose up -d rabbitmq
docker-compose up -d gateway
docker-compose up -d storage

Test services

Gateway service expose document REST api on /api/v1/documents:7654. JSON documents can be published to this api via curl.

// request
curl -v -XPOST "http://localhost:7654/api/v1/documents" \
--header "Content-Type: application/json" \
--data '
{
  "id": "1111",
  "name": "dot",
  "timestam": 89211232
}
'

// output
Note: Unnecessary use of -X or --request, POST is already inferred.
*   Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 7654 (#0)
> POST /api/v1/documents HTTP/1.1
> Host: localhost:7654
> User-Agent: curl/7.54.0
> Accept: */*
> Content-Type: application/json
> Content-Length: 63
>
* upload completely sent off: 63 out of 63 bytes
< HTTP/1.1 201 Created
< Date: Sun, 20 Oct 2019 01:11:21 GMT
< Content-Length: 7
< Content-Type: text/plain; charset=utf-8
<
* Connection #0 to host localhost left intact
Created

Rabbitmq admin console can be access via http://localhost:15672/#. The queue informations, broker informations etc can be viewd from this admin console.

// rabbitmq queues can be viewed from here
//  username - admin
//  password - admin
http://localhost:15672/#/queues

Reference:

• https://jbrandhorst.com/post/go-protobuf-tips/
• https://tutorialedge.net/golang/go-protocol-buffer-tutorial/
• https://kjanshair.github.io/2018/08/20/demystifying-protocol-buffers-and-grpc-with-go/
• https://medium.com/rahasak/microservice-response-aggregate-with-golang-goroutines-6aa84aea6fca -"Microservice response aggregate with golang and kafka".
• https://bit.ly/2MCczkQ "Work queue with Go and RabbitMQ".
• https://www.rabbitmq.com/tutorials/tutorial-one-go.html -"rabbitmq get Start".