configuration.go

package main

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

//Configuration holds data cleaned from our ENV variables or passed through cmd line
type Configuration struct {
	Host     	string
	Port     	string
	Password 	string
	Loglevel 	string
	BloomSize uint
	Shard 	 	string
}

//Global access to configuration variables
var c = readConfig()

func readConfig() (c Configuration) {
	//Command Line Flags. If command line flag is blank, use ENV instead
	var flagHost string
	flag.StringVar(&flagHost, "host", os.Getenv("AUTHTABLES_HOST"), "hostname for redis")
	var flagPort string
	flag.StringVar(&flagPort, "port", os.Getenv("AUTHTABLES_PORT"), "port for redis")
	var flagPW string
	flag.StringVar(&flagPW, "password", os.Getenv("AUTHTABLES_PW"), "password for redis")
	var flagLoglevel string
	flag.StringVar(&flagLoglevel, "loglevel", os.Getenv("AUTHTABLES_LOGLEVEL"), "level of logging (debug, info, warn, error)")
	var flagBloomSize uint
	d, _  := strconv.ParseUint(os.Getenv("AUTHTABLES_BLOOMSIZE"), 0, 32)
	flag.UintVar(&flagBloomSize, "bloomsize", uint(d), "size of bloom filter (default 1e9)")
	var flagShard string
	flag.StringVar(&flagShard, "shard", os.Getenv("AUTHTABLES_SHARD"), "name of this shard (prefix's keys within redis)")

	flag.Parse()

	if (flagHost == "" || flagPort == "" || flagLoglevel == "" || flagBloomSize == 0) {
		log.Error("Important things are not configured. You need to have your environment variables set, a .env file (docker), or pass valid data in command line arguments.")
	}


	//We're going to load this with config data. See struct!
	configuration := Configuration{}

	configuration.Host = flagHost
	configuration.Port = flagPort
	configuration.Password = flagPW
	configuration.Loglevel = flagLoglevel
	configuration.BloomSize = flagBloomSize
	configuration.Shard = flagShard

	return configuration
}