详解Golang如何在编译时注入版本信息

$ docker --version
Docker version 20.10.17, build 100c701
$ docker version
...
//输出太长，这里就不展示了

$ curl http://127.0.0.1:8080/version | jq
{
  "Build Time": "Fri, 16 Jun 2023 16:19:23 +0800",
  "Git Commit": "b554659",
  "Go Version": "go1.19",
  "OS/Arch": "darwin/amd64",
  "version": "0.9.2"
}

package config
var (
	Version   string  //代码版本号
	GitCommit string  //Git提交号
	BuildTime string  //编译时间
)

runtime.Version()  //Go版本
runtime.GOOS       //操作系统
runtime.GOARCH     //平台架构

rootCmd.Version = config.Version
rootCmd.SetVersionTemplate(fmt.Sprintf(`{{with .Name}}{{printf "%%s version information: " .}}{{end}}
    {{printf "Version:    %%s" .Version}}
    Git Commit: %s
    Build Time: %s
    Go version: %s
    OS/Arch:    %s/%s
`, config.GitCommit, config.BuildTime, runtime.Version(), runtime.GOOS, runtime.GOARCH))

func Version(ctx *gin.Context) {
    ctx.Writer.Header().Set("Content-Type", "application/json")
    ctx.Writer.WriteHeader(http.StatusOK)
    json.NewEncoder(ctx.Writer).Encode(map[string]string{
        "version":    config.Version,
        "Git Commit": config.GitCommit,
        "Build Time": config.BuildTime,
        "Go Version": runtime.Version(),
        "OS/Arch":    runtime.GOOS + "/" + runtime.GOARCH,
    })
}

VERSION    = $(shell git describe --tags --always)
GIT_COMMIT = $(shell git rev-parse --short HEAD)
BUILD_TIME = $(shell date -R)

define LDFLAGS
"-X 'github.com/myname/myapp/config.Version=${VERSION}' \
-X 'github.com/myname/myapp/config.GitCommit=${GIT_COMMIT}' \
-X 'github.com/myname/myapp/config.BuildTime=${BUILD_TIME}'"
endef
build:
    go build -ldflags ${LDFLAGS} -o myapp_${VERSION} .

$ make build
...
//编译过程，省略输出
$ myapp --version
myapp version information: 
    Version:    0.9.2
    Git Commit: b554659
    Build Time: Sat, 17 Jun 2023 11:30:44 +0800
    Go version: go1.20.5
    OS/Arch:    darwin/arm64
$ myapp
...
//启动进程，省略输出
$ curl http://127.0.0.1:8080/version | jq
{
  "Build Time": "Sat, 17 Jun 2023 11:30:44 +0800",
  "Git Commit": "b554659",
  "Go Version": "go1.20.5",
  "OS/Arch": "darwin/arm64",
  "version": "0.9.2"
}