params.go

package main

import (
	"flag"
	"path/filepath"
	"os"
	"strconv"
	log "github.com/Sirupsen/logrus"
)

func check(e error, m string) {
    if e != nil {
		log.Error("[Error]: ", m , e)
	}
}

type Params struct {
	Url string
	Prefix string
	Logfile string
	Files []string
	Refresh int
	Self bool
	Debug bool
}

func (p *Params) init() {
	var file_path string

	flag.StringVar(&p.Url, "url", "http://rancher-metadata.rancher.internal", "Rancher metadata url. RANCHER_TEMPLATE_URL")
	flag.StringVar(&p.Prefix, "prefix", "2016-07-29", "Rancher metadata prefix. RANCHER_TEMPLATE_PREFIX")
	flag.StringVar(&p.Logfile, "logfile", "/opt/tools/rancher-template/log/rancher-template.log", "Rancher template log fie. RANCHER_TEMPLATE_LOGFILE")
	flag.StringVar(&file_path, "templates", "/opt/tools/rancher-template/etc/*.yml", "Templates config files, wildcard allowed between quotes. RANCHER_TEMPLATE_FILES")
	flag.IntVar(&p.Refresh, "refresh", 300, "Rancher metadata refresh time in seconds. RANCHER_TEMPLATE_REFRESH")
	flag.BoolVar(&p.Self, "self", false, "Get self stack data or all. RANCHER_TEMPLATE_SELF")
	flag.BoolVar(&p.Debug, "debug", false, "Run in debug mode. RANCHER_TEMPLATE_DEBUG")

	flag.Parse()

	p.setEnvVar(&file_path)

	p.getFiles(file_path)
}

func (p *Params) setEnvVar(file_path *string) {
	var err error
	var aux_int int
	var aux_bool bool

	url := os.Getenv("RANCHER_TEMPLATE_URL")
	if len(url) > 0 { p.Url = url }

	prefix := os.Getenv("RANCHER_TEMPLATE_PREFIX")
	if len(prefix) > 0 { p.Prefix = prefix }

	logfile := os.Getenv("RANCHER_TEMPLATE_LOGFILE")
	if len(logfile) > 0 { p.Logfile = logfile }

	files := os.Getenv("RANCHER_TEMPLATE_FILES")
	if len(files) > 0 { *file_path = files }

	refresh := os.Getenv("RANCHER_TEMPLATE_REFRESH")
	if len(refresh) > 0 { 
		aux_int, err = strconv.Atoi(refresh) 
		if err == nil {
			p.Refresh = aux_int
		}
	}

	self := os.Getenv("RANCHER_TEMPLATE_SELF")
	if len(self) > 0 { 
		aux_bool, err = strconv.ParseBool(self) 
		if err == nil {
			p.Self = aux_bool
		}
	}

	debug := os.Getenv("RANCHER_TEMPLATE_DEBUG")
	if len(debug) > 0 { 
		aux_bool, err = strconv.ParseBool(debug) 
		if err == nil {
			p.Debug = aux_bool
		}
	}
}

func (p *Params) getFiles(f string) {
	var err error

	p.Files , err = filepath.Glob(f)
	if err != nil {
		log.Fatal(err)
	}
}

func getenv(key, fallback string) string {
    value := os.Getenv(key)
    if len(value) == 0 {
        return fallback
    }
    return value
}