240707_Gin实现Go REST API

去便利店买了罐鸡尾酒🍸，用Gin来build一个简单的todo-app.

Installation

参考 https://gin-gonic.com/docs/quickstart/

终端随便在哪个目录下: go install github.com/gin-gonic/gin@latest

$ go install github.com/gin-gonic/gin@latest
go: downloading github.com/gin-gonic/gin v1.10.0
go: downloading golang.org/x/net v0.25.0
go: downloading github.com/gin-contrib/sse v0.1.0
go: downloading github.com/mattn/go-isatty v0.0.20
go: downloading github.com/pelletier/go-toml/v2 v2.2.2
go: downloading github.com/ugorji/go/codec v1.2.12
go: downloading google.golang.org/protobuf v1.34.1
go: downloading github.com/go-playground/validator/v10 v10.20.0
go: downloading golang.org/x/sys v0.20.0
go: downloading golang.org/x/text v0.15.0
go: downloading github.com/gabriel-vasile/mimetype v1.4.3
go: downloading github.com/leodido/go-urn v1.4.0
go: downloading github.com/go-playground/universal-translator v0.18.1
go: downloading golang.org/x/crypto v0.23.0
go: downloading github.com/go-playground/locales v0.14.1
package github.com/gin-gonic/gin is not a main package

然后GOPATH(go env查看)的目录下就会有下载了的源码

/home/hl_tang/go/pkg/mod/github.com目录下确实多了个gin-gonic目录

Set up

创建项目文件夹

1	mkdir todo-app

cd进去

初始化go module

$ go mod init example/todo-app
go: creating new go.mod: module example/todo-app
go: to add module requirements and sums:
	go mod tidy

然后项目根目录下生成了一个go.mod文件

不初始化go module，而直接开个文件写入代码，go run运行。可能会报错: no required module provides package github.com/gin-gonic/gin: go.mod file not found in current directory or any parent directory;

使用 go get 来获取和更新依赖包 (其实用go mod tidy也行)

$ go get github.com/gin-gonic/gin
go: downloading github.com/bytedance/sonic v1.11.6
go: downloading github.com/goccy/go-json v0.10.2
go: downloading github.com/json-iterator/go v1.1.12
go: downloading github.com/modern-go/reflect2 v1.0.2
go: downloading github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd
go: downloading golang.org/x/arch v0.8.0
go: downloading github.com/cloudwego/base64x v0.1.4
go: downloading github.com/twitchyliquid64/golang-asm v0.15.1
go: downloading github.com/bytedance/sonic/loader v0.1.1
go: downloading github.com/klauspost/cpuid/v2 v2.2.7
go: downloading github.com/cloudwego/iasm v0.2.0
go: added github.com/bytedance/sonic v1.11.6
go: added github.com/bytedance/sonic/loader v0.1.1
go: added github.com/cloudwego/base64x v0.1.4
go: added github.com/cloudwego/iasm v0.2.0
go: added github.com/gabriel-vasile/mimetype v1.4.3
go: added github.com/gin-contrib/sse v0.1.0
go: added github.com/gin-gonic/gin v1.10.0
go: added github.com/go-playground/locales v0.14.1
go: added github.com/go-playground/universal-translator v0.18.1
go: added github.com/go-playground/validator/v10 v10.20.0
go: added github.com/goccy/go-json v0.10.2
go: added github.com/json-iterator/go v1.1.12
go: added github.com/klauspost/cpuid/v2 v2.2.7
go: added github.com/leodido/go-urn v1.4.0
go: added github.com/mattn/go-isatty v0.0.20
go: added github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd
go: added github.com/modern-go/reflect2 v1.0.2
go: added github.com/pelletier/go-toml/v2 v2.2.2
go: added github.com/twitchyliquid64/golang-asm v0.15.1
go: added github.com/ugorji/go/codec v1.2.12
go: added golang.org/x/arch v0.8.0
go: added golang.org/x/crypto v0.23.0
go: added golang.org/x/net v0.25.0
go: added golang.org/x/sys v0.20.0
go: added golang.org/x/text v0.15.0
go: added google.golang.org/protobuf v1.34.1
go: added gopkg.in/yaml.v3 v3.0.1

可以发现go get github.com/gin-gonic/gin时依然下载了一些刚刚go install没有的东西。比如$GOPATH/pkg/mod/github.com目录下又多了个字节的 JSON 序列化/反序列化库bytedance/sonic

然后go: added把依赖信息写入go.mod文件中的require

不go get管理依赖，而直接开个文件写入代码，go run运行。可能会报错: no required module provides package github.com/gin-gonic/gin; to add it:
go get github.com/gin-gonic/gin

但确实不go get，而用go mod tidy也是work的而且可能更好吧

测试

package main

import "github.com/gin-gonic/gin"

func main() {
	r := gin.Default()
	r.GET("/ping", func(c *gin.Context) {
		c.JSON(200, gin.H{
			"message": "pong",
		})
	})
	r.Run() // listen and serve on 0.0.0.0:8080
}