一. cobra是什么
cobra是一个命令行程序库,可以用来编写命令行程序。同时,它也提供了一个脚手架,用于生成基于 cobra 的应用程序框架。非常多知名的开源项目使用了 cobra 库构建命令行,如Kubernetes、Hugo、etcd等等等等。
二. 引入cobra库
bash
go get -u github.com/spf13/cobra
三. go示例代码
Go
package main
import (
"fmt"
"github.com/spf13/cobra"
"os"
"strings"
)
var (
Verbose bool
ConfigPath string
SomeString string
)
func main() {
Execute()
return
}
var rootCmd = &cobra.Command{
Use: "root",
Short: "the short description shown in the 'help' output.",
Long: `root description detail
Long is the long message shown in the 'help <this-command>' output.`,
Run: func(cmd *cobra.Command, args []string) {
// Do Stuff Here
fmt.Printf("root verbose: %v\n", Verbose)
fmt.Printf("root config: %s\n", ConfigPath)
fmt.Printf("root string: %s\n", SomeString)
},
}
func Execute() {
if err := rootCmd.Execute(); err != nil {
fmt.Println(err)
os.Exit(1)
}
}
var apiCmd = &cobra.Command{
Use: "api",
Short: "api short description",
Long: `api long description`,
Run: func(cmd *cobra.Command, args []string) {
// Do Stuff Here
fmt.Printf("api verbose: %v\n", Verbose)
fmt.Printf("api config: %s\n", ConfigPath)
fmt.Printf("api string: %s\n", SomeString)
},
}
var adminCmd = &cobra.Command{
Use: "admin",
Short: "admin short description",
Long: `admin long description`,
Run: func(cmd *cobra.Command, args []string) {
// Do Stuff Here
fmt.Printf("admin verbose: %v\n", Verbose)
fmt.Printf("admin config: %s\n", ConfigPath)
fmt.Printf("admin string: %s\n", SomeString)
},
}
var apiChildCmd = &cobra.Command{
Use: "apiChild",
Short: "apiChild short description",
Long: `apiChild long description`,
Run: func(cmd *cobra.Command, args []string) {
// Do Stuff Here
fmt.Printf("apiChild verbose: %v\n", Verbose)
fmt.Printf("apiChild config: %s\n", ConfigPath)
fmt.Printf("apiChild string: %s\n", SomeString)
},
}
func init() {
rootCmd.AddCommand(apiCmd, adminCmd)
apiCmd.AddCommand(apiChildCmd)
// persistent是全局选项,对应的方法为PersistentFlags
rootCmd.PersistentFlags().BoolVarP(&Verbose, "verbose", "v", false, "全局版本")
rootCmd.PersistentFlags().StringVarP(&SomeString, "string", "s", "null", "字符串")
// local为本地选项,对应方法为Flags,只对指定的Command生效
apiCmd.Flags().StringVarP(&ConfigPath, "config", "c", "", "读取文件路径")
}
// persistent是全局选项,对应的方法为PersistentFlags
rootCmd.PersistentFlags().BoolVarP(&Verbose, "verbose", "v", false, "全局版本")
rootCmd.PersistentFlags().StringVarP(&SomeString, "string", "s", "null", "字符串")
// local为本地选项,对应方法为Flags,只对指定的Command生效
apiCmd.Flags().StringVarP(&ConfigPath, "config", "c", "", "读取文件路径")
四. 结果
Go
go run ./main.go -v -s aaa
root verbose: true
root config:
root string: aaa
Go
go run ./main.go api -v -s aaa -c config
api verbose: true
api config: config
api string: aaa
Go
go run ./main.go api apiChild -v -s aaa
apiChild verbose: true
apiChild config:
apiChild string: aaa
只有api可以设置-c参数
五. 添加svc库
svc库将服务分为初始化、启动服务、结束服务三个阶段。
引入svc包
go get -u github.com/judwhite/go-svc
与cobra结合,如下为项目启动示例代码
Go
func main() {
Execute()
return
}
var rootCmd = &cobra.Command{
Use: "server",
Short: "",
Long: "",
Run: func(cmd *cobra.Command, args []string) {
},
}
func Execute() {
if err := rootCmd.Execute(); err != nil {
fmt.Println(err)
os.Exit(1)
}
}
type Application struct {
}
var cfgFile *string
var startCmd = &cobra.Command{
Use: "start",
Short: "start the api server",
Long: `usage example:
server(.exe) start -c apollo.json
start the server`,
Run: func(cmd *cobra.Command, args []string) {
app := &Application{}
if err := svc.Run(app, syscall.SIGINT, syscall.SIGTERM); err != nil {
fmt.Println(err)
}
},
}
func init() {
rootCmd.AddCommand(startCmd)
cfgFile = startCmd.Flags().StringP("config", "c", "", "config file (required)")
startCmd.MarkFlagRequired("config")
}
func (app *Application) Init(env svc.Environment) error {
// do init
return nil
}
func (app *Application) Start() error {
// do start
return nil
}
func (app *Application) Stop() error {
// do stop
return nil
}