echoStars

A web services server monitor

Collaboration

• Trello
• Repo
• Authors: emanuelpeg@gmail.com, axel.salmeron@gmail.com, juanpabloalvis@gmail.com, sergio.delatorre@unmsm.edu.pe

Prerequisites

• Go installation:

  Install go in the local machine. It should be done setting the environment variable GOROOT. The GOROOT variable points where your Go SDK is located.

  Please refer to Go Lang installation page for more details.

  You can check in your terminal the installation with:

    go build

• Text editor or your preferred IDE.

Build and run application using CLI

Go to the directory of the source code and build:

  go build

Then, you can run the application

$env:APP_PROFILE="dev"; go run main.go

the AP_PROFILE environment variable will indicate which .property file the app will use

EchoStars is a Web application that runs on port 1323. Please, check logs and then you can open in your preferred browser; here you have the api documentation uri.

Write test with Mocks

Runing all tests

go test -v ./...

Test examples "Greetings"

In the folder greetings there are a few examples of unit tests

GoMock

Install gomock

go install go.uber.org/mock/mockgen@latest

Then run mockgen with the file that has the interface that should be mock mockgen -source=<sourceFilePath> -destination=<destinationFilePath>

For example :

mockgen -source=C:\projects\goLang\echoStars\greetings\greetings.go -destination=C:\projects\goLang\echoStars\greetings\greetings.mock.go

The Steps are

1. Define an interface that you wish to mock.

   type MyInterface interface {
     SomeMethod(x int64, y string)
   }

2. Use mockgen to generate a mock from the interface.

3. Use the mock in a test:

         func TestMyThing(t *testing.T) {
           mockCtrl := gomock.NewController(t)
           defer mockCtrl.Finish()
           mockObj := something.NewMockMyInterface(mockCtrl)
           mockObj.EXPECT().SomeMethod(4, "blah")
           // pass mockObj to a real object and play with it.
         }

Routines

Go to the routines subdirectory and use go run . to run the routines test code.

Express test server

ExpressJs server for testing the monitor service with 3 endpoints.

• http://localhost:3000/healthCheck/success: always succeeds
• http://localhost:3000/healthCheck/error always fails
• http://localhost:3000/healthCheck/sketchy fails 10% of the time

When running the monitor service these endpoints will be checked periodically even if the test server is down.

To run the test server go to the express-test-server subdirectory and run:

npm install
npm start

Docker

To run the app in docker use docker-compose up. Add the --build option if you want to force a build of the images before staring the containers. Add the -d option if you want docker-compose to run in dettached mode

To stop the containers while running in dettached mode run docker-compose down. Use -v if you want to remove the volumes

To check the logs use docker-compose logs [service-name] where service-name is optional

Use docker-compose ps to list the currently running containers

GRpc

Install

Install with following commands:

$ go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
go: downloading google.golang.org/protobuf v1.28.1
$ go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest
go: downloading google.golang.org/grpc v1.2.1

Develop

To develop a GRpc services should follow these steps:

1. Write a .proto, for example :

syntax = "proto3";

package greetings;
option go_package = "echoStarts/greetings";

message HelloRequest {
  string message = 1;
}

message HelloResponse {
  string message = 1;
}

message HelloWoldRequest {
}

message HelloWoldResponse {
  string message = 1;
}

//  Greetings service.
service GreeterServiceGrpc {

  rpc Hello(HelloRequest) returns (HelloResponse) {}
  rpc HelloWold(HelloWoldRequest) returns (stream HelloWoldResponse) {}

}

2. Generate code from the .proto. With this command:

protoc --go_out=. --go_opt=paths=source_relative --go-grpc_out=. --go-grpc_opt=paths=source_relative ./greetings/greetings.proto

3. Write a server and a client. see server and client