go-project-demo

This project is for demonstrating go project purpose

This repo is one of the microservices. Other related repo are elasticsearch-monstache-demo and vue-project-demo

Please setup the project under this order:

1. go-project-demo
2. elasticsearch-monstache-demo
3. vue-project-demo

Quick usage

docker compose

Run the API server

docker-compose up

Run unit test

make cover

Todo list:

• Create item API
• Get item API
• Provide swagger
• Add sentry to monitor error (may be)
• MongoDB indexing
• Gomock test
• User auth with JWT

Useful information

Gomock

1. Gomock tutorial: https://blog.codecentric.de/en/2017/08/gomock-tutorial/

Ginkgo

A Golang Behavior-Driven Development ("BDD") testing framework

Example

Describe("the strings package", func() {
  Context("strings.Contains()", func() {
    When("the string contains the substring in the middle", func() {
      It("returns `true`", func() {
        Expect(strings.Contains("Ginkgo is awesome", "is")).To(BeTrue())
      })
    })
  })
})

Gomega

Gomega is a go matcher used in go test asserting

Example

Equal(...)
BeEquivalentTo(...)
BeNil()
BeZero()
BeTrue()
BeFalse()

Notes

gRPC

everytime we updated the .proto file, we use this cmd to regenerate interface file

export PATH="$PATH:$(go env GOPATH)/bin"
cd ../api/proto/helloworld
protoc --go_out=. --go_opt=paths=source_relative     --go-grpc_out=. --go-grpc_opt=paths=source_relative     helloworld.proto

In gRPC with Go, when you use the Protocol Buffers compiler (protoc) to generate Go code from .proto files, you end up with two types of files:

1. helloworld.pb.go: This file contains:

   • Struct definitions for each of your Protocol Buffers messages.
   • Code to encode (marshal) and decode (unmarshal) these messages to and from binary format.
   • Any enum definitions from your .proto file as Go constants.
   • file_helloworld_proto_rawDesc is the whole .proto file in binary format

2. helloworld_grpc.pb.go: This file is specifically for gRPC and includes:

   • Client and server interfaces for the gRPC services defined in your .proto file.
   • Code that helps implement these services on the server-side and call them on the client-side.

Essentially, xxx.pb.go deals with data structures, while xxx_grpc.pb.go handles the communication aspects using those structures in gRPC.

Troubleshooting

DeadlineExceeded

 2024/08/18 05:35:38 Error greeting aac: rpc error: code = DeadlineExceeded desc = context deadline exceeded

This error message indicates that the operation exceeded the time allowed by the deadline set in the context. This is commonly encountered in network and RPC operations where you've defined a maximum duration that an operation can take, and the operation did not complete within this timeframe.

Common Causes

1. Network Delays: The server might be taking too long to respond due to network latency, or the server itself might be overloaded and thus slow to handle requests.

2. Server Processing Time: The server-side operation might be more time-consuming than anticipated. This could be due to data processing requirements, database access delays, or other computational tasks.

3. Improper Timeout Settings: The client might have set a deadline that is too short for the operation to realistically complete in normal conditions.