package main
import (
"fmt"
"log"
"os"
"os/signal"
"time"
"github.com/fsnotify/fsnotify"
"github.com/spf13/pflag"
"github.com/spf13/viper"
)
// command line flags
var (
port *int = pflag.IntP("port", "p", 9001, "getwtxt will serve from this port")
logfile *string = pflag.StringP("logfile", "l", "getwtxt.log", "File for logging output")
twtxtfile *string = pflag.StringP("twtxtfile", "f", "/var/twtxt/twtxt.txt", "Registry file for getwtxt")
stdoutLogging *bool = pflag.BoolP("stdout", "o", true, "Log to stdout rather than to a file")
)
// config object
var confObj = &configuration{}
// signals to close the log file
var closelog = make(chan bool, 1)
func init() {
titleScreen()
initConfig()
initLogging()
watchForInterrupt()
}
func initConfig() {
pflag.Parse()
viper.BindPFlags(pflag.CommandLine)
viper.SetConfigName("getwtxt")
viper.AddConfigPath(".")
viper.AddConfigPath("/usr/local/getwtxt")
viper.AddConfigPath("/etc")
viper.AddConfigPath("/usr/local/etc")
log.Printf("Loading configuration ...\n")
if err := viper.ReadInConfig(); err != nil {
log.Printf("Error reading config file: %v\n", err)
log.Printf("Using defaults ...\n")
}
// separate thread to watch for config file changes.
// will log event then run rebindConfig()
viper.WatchConfig()
viper.OnConfigChange(func(e fsnotify.Event) {
log.Printf("Config file change detected. Reloading...\n")
rebindConfig()
})
viper.SetDefault("port", 9001)
viper.SetDefault("logfile", "getwtxt.log")
viper.SetDefault("twtxtfile", "/var/twtxt/twtxt.txt")
confObj.port = viper.GetInt("port")
confObj.logfile = viper.GetString("logfile")
confObj.twtxtfile = viper.GetString("twtxtfile")
confObj.stdoutLogging = viper.GetBool("stdoutLogging")
}
func initLogging() {
// only open a log file if it's necessary
if confObj.stdoutLogging {
log.SetOutput(os.Stdout)
} else {
logfile, err := os.OpenFile(confObj.logfile, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0600)
if err != nil {
log.Printf("Could not open log file: %v\n", err)
}
// Listen for the signal to close the log file
// in a separate thread. Passing it as an argument
// to prevent race conditions when the config is
// reloaded.
go func(logfile *os.File) {
<-closelog
log.Printf("Closing log file ...\n")
err = logfile.Close()
if err != nil {
log.Printf("Couldn't close log file: %v\n", err)
}
}(logfile)
log.SetOutput(logfile)
}
}
func rebindConfig() {
// signal to close the log file then wait
if !confObj.stdoutLogging {
closelog <- true
}
// reassign values to the config object
confObj.port = viper.GetInt("port")
confObj.logfile = viper.GetString("logfile")
confObj.twtxtfile = viper.GetString("twtxtfile")
confObj.stdoutLogging = viper.GetBool("stdoutLogging")
// reinitialize logging
initLogging()
}
// Watch for SIGINT aka ^C
// Close the log file then exit
func watchForInterrupt() {
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt)
go func() {
for sigint := range c {
log.Printf("\n\nCaught %v. Cleaning up ...\n", sigint)
if !confObj.stdoutLogging {
// signal to close the log file
closelog <- true
time.Sleep(20 * time.Millisecond)
}
close(closelog)
os.Exit(0)
}
}()
}
func titleScreen() {
fmt.Printf(`
_ _ _
__ _ ___| |___ _| |___ _| |_
/ _ |/ _ \ __\ \ /\ / / __\ \/ / __|
| (_| | __/ |_ \ V V /| |_ > <| |_
\__, |\___|\__| \_/\_/ \__/_/\_\\__|
|___/
version ` + getwtxt + `
github.com/gbmor/getwtxt
GPL v3
`)
}