PS C:\Users\tzh> docker version
Client: Docker Engine - Community
 Version:      19.03.4
 API version:    1.40
 Go version:    go1.12.10
 Git commit:    9013bf5
 Built:       Thu Oct 17 23:44:48 2019
 OS/Arch:      windows/amd64
 Experimental:   false

Server: Docker Engine - Community
 Engine:
 Version:     19.03.4
 API version:   1.40 (minimum version 1.12)
 Go version:    go1.12.10
 Git commit:    9013bf5
 Built:      Thu Oct 17 23:50:38 2019
 OS/Arch:     linux/amd64
 Experimental:   false
 containerd:
 Version:     v1.2.10
 GitCommit:    b34a5c8af56e510852c35414db4c1f4fa6172339
 runc:
 Version:     1.0.0-rc8+dev
 GitCommit:    3e425f80a8c931f88e6d94a8c831b9d5aa481657
 docker-init:
 Version:     0.18.0
 GitCommit:    fec3683

-X importpath.name=value
  Set the value of the string variable in importpath named name to value.
  This is only effective if the variable is declared in the source code either uninitialized
  or initialized to a constant string expression. -X will not work if the initializer makes
  a function call or refers to other variables.
  Note that before Go 1.5 this option took two separate arguments.

package buildinfo

var BuildTime string

package version

// 这些值应该是从外部传入的
var (
  gitTag    string = ""
  gitCommit  string = "$Format:%H$"     // sha1 from git, output of $(git rev-parse HEAD)
  gitTreeState string = "not a git tree"    // state of git tree, either "clean" or "dirty"
  buildDate  string = "1970-01-01T00:00:00Z" // build date in ISO8601 format, output of $(date -u +'%Y-%m-%dT%H:%M:%SZ')
)

package version

import (
  "fmt"
  "runtime"
)

// 构建时的版本信息
type VersionInfo struct {
  GitTag    string `json:"git_tag"`
  GitCommit  string `json:"git_commit"`
  GitTreeState string `json:"git_tree_state"`
  BuildDate  string `json:"build_date"`
  GoVersion  string `json:"go_version"`
  Compiler   string `json:"compiler"`
  Platform   string `json:"platform"`
}

func (info VersionInfo) String() string {
  return info.GitTag
}

func Get() VersionInfo {
  return VersionInfo{
    GitTag:    gitTag,
    GitCommit:  gitCommit,
    GitTreeState: gitTreeState,
    BuildDate:  buildDate,
    GoVersion:  runtime.Version(),
    Compiler:   runtime.Compiler,
    Platform:   fmt.Sprintf("%s/%s", runtime.GOOS, runtime.GOARCH),
  }
}

package cmd

import (
  "encoding/json"
  "fmt"

  "github.com/spf13/cobra"
  "tzh.com/web/pkg/version"
)

var versionCmd = &cobra.Command{
  Use:  "version",
  Short: "Print the version info of server",
  Long: "Print the version info of server",
  Run: func(cmd *cobra.Command, args []string) {
    printVersion()
  },
}

func printVersion() {
  info := version.Get()
  infoj, err := json.MarshalIndent(&info, "", " ") // 加一点缩进
  if err != nil {
    fmt.Printf("遇到了错误: %v\n", err)
  }
  fmt.Println(string(infoj))
}

// 初始化, 设置 flag 等
func init() {
  cobra.OnInitialize(initConfig)
  rootCmd.PersistentFlags().StringVarP(&cfgFile, "config", "c", "./conf/config.yaml", "config file (default: ./conf/config.yaml)")
  rootCmd.AddCommand(versionCmd)
}

SHELL := /bin/bash
BASEDIR = $(shell pwd)

# build with version infos
versionDir = "tzh.com/web/pkg/version"
gitTag = $(shell if [ "`git describe --tags --abbrev=0 2>/dev/null`" != "" ];then git describe --tags --abbrev=0; else git log --pretty=format:'%h' -n 1; fi)
buildDate = $(shell TZ=UTC date +%FT%T%z)
gitCommit = $(shell git log --pretty=format:'%H' -n 1)
gitTreeState = $(shell if git status|grep -q 'clean';then echo clean; else echo dirty; fi)

ldflags="-w -X ${versionDir}.gitTag=${gitTag} -X ${versionDir}.buildDate=${buildDate} -X ${versionDir}.gitCommit=${gitCommit} -X ${versionDir}.gitTreeState=${gitTreeState}"

all: gotool build
build:
  go build -ldflags ${ldflags} ./
run:
  go run -ldflags ${ldflags} ./
docker:
  go run -ldflags ${ldflags} ./ -c ./conf/config_docker.yaml