Day-01.md

Day 1: Getting Started with Go and Cobra

Goal: Set up your Go environment and create a basic Cobra CLI application.

Steps:

1. Install Go: If you don't have Go installed, follow the official instructions: https://golang.org/doc/install

2. Install Cobra CLI Generator:

go install github.com/spf13/cobra-cli@latest

3. Create a new Go module:

mkdir netcli
cd netcli
go mod init github.com/yourusername/netcli # Replace with your GitHub username

4. Initialize Cobra project:

In some cases it's necessary to install cobra-cli: https://formulae.brew.sh/formula/cobra-cli

cobra-cli init

This will create a cmd directory with root.go and main.go.

Code Example (main.go):

package main

import "github.com/yourusername/netcli/cmd" // Replace with your module path

func main() {
	cmd.Execute()
}

Code Example (cmd/root.go):

package cmd

import (
	"os"
	"github.com/spf13/cobra"
)

var cfgFile string

// rootCmd represents the base command when called without any subcommands
var rootCmd = &cobra.Command{
	Use:   "netcli",
	Short: "A CLI tool for network automation tasks.",
	Long: `netcli is a powerful command-line interface tool designed to
streamline various network automation tasks, from checking device reachability
to managing configurations.`,
	// Uncomment the following line if your bare application
	// has an action associated with it:
	// Run: func(cmd *cobra.Command, args []string) { },
}

// Execute adds all child commands to the root command and sets flags appropriately.
// This is called by main.main(). It only needs to happen once to the rootCmd.
func Execute() {
	err := rootCmd.Execute()
	if err != nil {
		os.Exit(1)
	}
}

func init() {
	// Here you will define your flags and configuration settings.
	// Cobra supports persistent flags, which, if defined here,
	// will be available to all subcommands.
	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.netcli.yaml)")

	// Cobra also supports local flags, which will only run
	// when this action is called directly.
	// rootCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
}

Run your app:

go run main.go