Some of the content on Go Modules

installation

Configuration Environment

Enable Go Modules

go modIn Go >= 1.13only enabled by default, in Go >= 1.11has begun to support the go mod.

Set Environment Variables

# 启用go module
export GO111MODULE=on

# 设置GOPATH，开启go mod之后，这个目录主要用来存放依赖包
export GOPATH=~/go_modules

# 设置go代理，在运行go test/build等时会自动下载依赖
# 使用go get下载依赖需要在GOPATH中执行才会使用代理
export GOPROXY=https://goproxy.io

go mod use

In $GOPATH/srcany directory other than create a directory,

mkdir -p /home/gopher/project
cd /home/gopher/project

This directory is the root directory of your project, create a mod file in the directory management

go mod init project

If you put this project on github, then you can write when you create a file, project name for your github project

go mod init github.com/YourName/project

go.modThe initial content cat go.modis:

module project

go 1.12

go.modOnly you need to create once, in a project in the root directory of the project Gowill automatically find all the current directory 父级目录until you find go.mod.

Introduced on the package definition and package custom

• A directory only by a defined package

  比如在project项目中有了一个hello.go的文件，文中定义了package hello，
  这样，当你再在project中创建了一个world.go的文件，其中定义了package world会报错，无法加载package

• Each package defines, in a directory. Recommend the same directory name and package name defined in the package.

  project
  ├── go.mod
  ├── hello
  │   ├── hello.go
  │   └── hello1.go
  ├── main.go
  └── world
      ├── world.go
      └── world1.go
  
  其中hello目录中所有文件的包定义均为package hello，hello目录中所有文件的包定义均为package world

go mod management

• Create a new module

  # 创建了一个新的模块，初始化 `go.mod` 文件并且生成相应的描述
  go mod init

• Add Dependency

  # build，test和其它构建代码包的命令，会在需要的时候在go.mod文件中添加新的依赖项
  # 最好不要自己修改go.mod文件，因为在Go在向go.mod中添加依赖项的时候
  # 同时会向go.sum中的hash对比，确定依赖是否修改。
  go build
  go test

• View all current dependencies

  # 列出了当前模块所有的依赖项
  go list -m all

• Modify the specified dependency versions (or add a new dependency)

  # 修改或添加
  # go get -u 会更新依赖
  # 获取指定版本的形式 go get rsc.io/[email protected]
  go get

• Removing unused dependencies

  go mod tidy