main.go

package main

import (
    "os"
    "fmt"
    "log"
    "strings"
    "io/ioutil"
    "log/syslog"
    "github.com/jessevdk/go-flags"
)

var config *SSHConfig
var authLogger *syslog.Writer

var opts struct {
    Config      string      `short:"c" long:"config" description:"Configuration YAML file location" required:"true"`
}

func main() {
    _, err := flags.Parse(&opts)
    if err != nil {
        os.Exit(1)
    }

    if _, err := os.Stat(opts.Config); err != nil {
        log.Fatalf("Specified config file doesn't exist!\n")
    }

    config, err = fetchConfig(opts.Config)
    if err != nil {
        panic(err)
    }

    authLogger, err = syslog.New(syslog.LOG_AUTH | syslog.LOG_ALERT, "ssh-bastion")
    if err != nil {
        panic(err)
    }

    s, err := NewSSHServer()
    if err != nil {
        panic(err)
    }

    s.ListenAndServe(config.Global.ListenPath)
}

func GetMOTD() (string) {
    if len(config.Global.MOTDPath) > 0 {
        str, err := ioutil.ReadFile(config.Global.MOTDPath)
        if err != nil {
            log.Printf("Error reading MOTD file (%s): %s", config.Global.MOTDPath, err)
            return ""
        } else {
            return strings.Replace(string(str), "\n", "\r\n", -1)
        }
    } else {
        return ""
    }
}

func WriteAuthLog(format string, v ...interface{}) {
    authLogger.Write([]byte(fmt.Sprintf(format, v...)))
}