Read content from .txt file and output the results to be used with .yaml files

formatter.go

package formatter

import (
	"fmt"
	"io/ioutil"
	"log"
	"strings"
)

type Formatter interface {
	Read() string
	Format(string) string
}

type proxyFormatter struct {
	Proxies []string
}

func NewProxyFormatter() Formatter {
	return &proxyFormatter{}
}

func (p *proxyFormatter) Read() string {
	content, err := ioutil.ReadFile("proxies.txt")

	if err != nil {
		log.Fatalln("Error occurred reading proxies.txt file", err.Error())
	}
	return string(content)
}

func (p *proxyFormatter) Format(content string) (res string) {
	proxies := strings.Split(content, "\n")

	for _, proxy := range proxies {
		res += fmt.Sprintf("- %s \n", proxy)
	}
	return
}

main.go

package main

import (
	"log"
	f "proxyformatter/formatter"
)

func main() {
	pf := f.NewProxyFormatter()

	resp := pf.Read()
	results := pf.Format(resp)

	log.Println(results)
}