How to Organize a Go Project

The official has a good information on how to structure your Go code. In this blog, I am going to explain a little bit more about it. Let's say we want to create a Go project containing a command and a package.

workspace1/
|-- build.sh
`-- src
    `-- mylib
        |-- hello
        |   `-- hello.go (package)
        `-- main.go (command)

hello.go

package hello

import "fmt"

func SayHello() {
    fmt.Println("Hello")
}

main.go

package main

import "mylib/hello"

func main() {
    hello.SayHello()
}

build.sh

#!/bin/bash

export GOPATH=`pwd`
go install mylib/hello
go install mylib

Calling build.sh will create this structure.

workspace1/
|-- bin
|   `-- mylib (executable)
|-- build.sh
|-- pkg
|   `-- linux_amd64
|       `-- mylib
|           `-- hello.a (library)
`-- src
    `-- mylib
        |-- hello
        |   `-- hello.go (package)
        `-- main.go (command)

In order to make mylib project go-gettable, let's make it into a Git project. Take a note that we will be creating a Git project in the mylib directory and not in the workspace1 directory.

1. cd workspace1/src/mylib
2. git init
3. git add .
4. git commit -m "Initial commit"
5. Push this repository to the remote URL

Now let's create another project that uses mylib. This new project is a simple project that uses mylib.

workspace2/
|-- build.sh
`-- src
    `-- myapp
        `-- app
            `-- app.go (command)

1. cd workspace2
2. git init
3. git add submodule [mylib_git_url] src/mydomain/user/mylib (the src/mydomain/user is just a convention, you can also set the path to src/mylib)

After the submodule addition, we will have this structure.

workspace2/
|-- build.sh
`-- src
    |-- myapp
    |   `-- app
    |       `-- app.go (command)
    `-- mydomain
        `-- user
            `-- mylib
                |-- hello
                |   `-- hello.go (package)
                `-- main.go (command)

app.go

package main

import (
    "fmt"
    "mydomain/user/mylib/hello"
)

func main() {
    fmt.Println("Do something")
    hello.SayHello()
}

build.sh

#!/bin/bash

export GOPATH=`pwd`
go install mydomain/user/mylib/hello
go install myapp/app

Calling build.sh will create this structure.

workspace2/
|-- bin
|   `-- app (executable)
|-- build.sh
|-- pkg
|   `-- linux_amd64
|       `-- mydomain
|           `-- user
|               `-- mylib
|                   `-- hello.a (library)
`-- src
    |-- myapp
    |   `-- app
    |       `-- app.go (command)
    `-- mydomain
        `-- user
            `-- mylib
                |-- hello
                |   `-- hello.go (package)
                `-- main.go (command - not used)