Initial commit

cmd/lsf/main.go

@@ -0,0 +1,137 @@
+// Command lsf provides functions to use the lsf with the commandline.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"path"
+	"strings"
+	"syscall"
+
+	"git.marceltransier.de/lsf"
+	"github.com/pkg/errors"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+var (
+	sessionCache string
+	username     string
+)
+
+func init() {
+	homeDir, err := os.UserHomeDir()
+	if err != nil {
+		log.Fatal(err)
+	}
+	defaultCacheDir := path.Join(homeDir, ".cache/go-lsf/sessions")
+	flag.StringVar(&sessionCache, "session-cache", defaultCacheDir, "path where the session tokens are located")
+	flag.StringVar(&username, "username", "", "username to login with in lsf")
+	flag.Parse()
+
+	err = os.MkdirAll(sessionCache, os.ModePerm)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func main() {
+	if len(username) == 0 {
+		var err error
+		username, err = readUsername()
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+
+	s, err := session(username)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Printf("s: %+v\n", s)
+}
+
+func readUsername() (string, error) {
+	var username string
+	fmt.Print("Username: ")
+	_, err := fmt.Scanf("%s", &username)
+	if err != nil {
+		return "", errors.Wrap(err, "could not read username")
+	}
+	return username, nil
+}
+
+func readPassword() (string, error) {
+	var password string
+	fmt.Print("Password: ")
+	b, err := terminal.ReadPassword(int(syscall.Stdin))
+	if err != nil {
+		return "", errors.Wrap(err, "could not read password")
+	}
+	fmt.Print("\n")
+	password = string(b)
+	return password, nil
+}
+
+func session(username string) (*lsf.Session, error) {
+	sessionPath := path.Join(sessionCache, username)
+	sessionFile, err := os.Open(sessionPath)
+	if err != nil {
+		pErr, ok := err.(*os.PathError)
+		if !ok {
+			return nil, err
+		}
+		errno, ok := pErr.Unwrap().(syscall.Errno)
+		if !ok {
+			return nil, err
+		}
+		if errno != syscall.ENOENT {
+			log.Fatal(err)
+		}
+		log.Printf("no session for %s cached\n", username)
+		return login(username)
+	}
+	defer sessionFile.Close()
+
+	b, err := ioutil.ReadAll(sessionFile)
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not read session file %s", sessionPath)
+	}
+	sid := strings.TrimSuffix(string(b), "\n")
+	s := &lsf.Session{
+		SID: sid,
+	}
+	valid, err := s.Valid()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not check session")
+	}
+	if !valid {
+		fmt.Println("session is not valid")
+		err := os.Remove(sessionPath)
+		if err != nil {
+			log.Println(errors.Wrap(err, "could not remove invalid session file"))
+		}
+		return login(username)
+	}
+	return s, nil
+}
+
+func login(username string) (*lsf.Session, error) {
+	password, err := readPassword()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not login")
+	}
+	s, err := lsf.Login(username, password)
+	if err != nil {
+		return nil, err
+	}
+	sessionPath := path.Join(sessionCache, username)
+	err = ioutil.WriteFile(sessionPath, []byte(s.SID), 0666)
+	if err != nil {
+		log.Println(errors.Wrap(err, "could not cache session id"))
+	}
+	return s, nil
+}