Setup xen vif bridges at boot for IDS

parse_vif.go

package main

import (
	"bufio"
	"fmt"
	"os/exec"
	"regexp"
	"strings"
)

func main() {
	suffixes := map[string]int{
		"    Bridge \"xenbr7\"": 7,
		"    Bridge \"xenbr8\"": 8,
		"    Bridge \"xenbr9\"": 9,
	}
	iface_numbers := make(chan int, 3)
	vifs := make(chan string, 3)
	vif_line := regexp.MustCompile(`vif[0-9]+.[0-9]`)

	output, _ := exec.Command("ovs-vsctl", []string{"show"}...).Output()

	scanner := bufio.NewScanner(strings.NewReader(string(output)))
	grabbing := false
	for scanner.Scan() {
		line := scanner.Text()
		if number, ok := suffixes[line]; ok {
			iface_numbers <- number
			grabbing = true
		} else if vif := vif_line.FindString(line); vif != "" {
			if !grabbing {
				continue
			}
			vifs <- vif
			grabbing = false
		}
	}

	for i := 0; i < 3; i++ {
		iface := <-iface_numbers
		vif := <-vifs
		args := strings.Fields(fmt.Sprintf(
			"-- set Bridge xenbr%d mirrors=@m -- --id=@eth%d get Port eth%d -- --id=@%s get Port %s -- --id=@m create Mirror name=eth%d-mirror select-dst-port=@eth%d select-src-port=@eth%d output-port=@%s",
			iface,
			iface,
			iface,
			vif,
			vif,
			iface,
			iface,
			iface,
			vif,
		))

		out, _ := exec.Command("ovs-vsctl", args...).Output()
		fmt.Print(string(out))
	}
}