Port old renameuser script and integrate it with towndb

Reviewed-on: tildetown/town#2

cmd/rename/main.go

@@ -0,0 +1,113 @@
+package main
+
+
+import (
+	"bufio"
+	"fmt"
+	"path"
+	"os"
+	"os/exec"
+
+	"git.tilde.town/tildetown/town/towndb"
+)
+
+func confirmRename() {
+	fmt.Println("this will kill all of the user's current processes. if you're doing this live you should give them a good contact if things break")
+
+	var text string
+
+	for text != "y\n" {
+		fmt.Print("enter 'y' to continue: ")
+		reader := bufio.NewReader(os.Stdin)
+		text, _ = reader.ReadString('\n')
+	}
+}
+
+func killUser(name string) (err error) {
+	cmd := exec.Command("pkill", "-SIGKILL", "-u", name)
+	cmd.Stderr = os.Stderr
+
+	if err = cmd.Run(); err != nil {
+		if exiterr, ok := err.(*exec.ExitError); ok {
+			if exiterr.ExitCode() == 1 {
+				return nil
+			}
+		}
+
+		return err
+	}
+
+	return nil
+}
+
+func usermod(old_name string, new_name string) (err error) {
+	cmd := exec.Command(
+		"usermod",
+		"-l", new_name,
+		"-m",
+		"-d", path.Join("/home", new_name),
+		old_name,
+	)
+	cmd.Stderr = os.Stderr
+
+	if err = cmd.Run(); err != nil {
+		return err
+	}
+
+	cmd = exec.Command("groupmod", "-n", new_name, old_name)
+	cmd.Stderr = os.Stderr
+
+	if err = cmd.Run(); err != nil {
+		return err
+	}
+
+	return
+}
+
+func renameDb(old_name string, new_name string) (err error) {
+	db, err := towndb.ConnectDB()
+	if err != nil {
+		return err
+	}
+
+	err = towndb.RenameUser(db, old_name, new_name)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func quit(text string) {
+	fmt.Println(text)
+	os.Exit(1)
+}
+
+func main() {
+	if len(os.Args) != 3 {
+		quit("usage: rename username new_username")
+	}
+
+	confirmRename()
+	old_name := os.Args[1]
+	new_name := os.Args[2]
+
+	if err := killUser(old_name); err != nil {
+		quit(fmt.Sprintf("pkill failed: %v", err))
+	}
+
+	fmt.Println("killed old processes")
+
+	if err := usermod(old_name, new_name); err != nil {
+		quit(fmt.Sprintf("unix user rename failed: %v", err))
+	}
+
+	fmt.Println("renamed unix user")
+
+	if err := renameDb(old_name, new_name); err != nil {
+		fmt.Println(fmt.Sprintf("couldn't rename user in /town/var/town.db: %v", err))
+		fmt.Println("something might be amiss with town.db")
+	} else {
+		fmt.Println("renamed user in /town/var/town.db")
+	}
+}

towndb/towndb.go

@@ -2,6 +2,7 @@ package towndb
 
 import (
 	"database/sql"
+	"fmt"
 	"time"
 
 	_ "github.com/mattn/go-sqlite3"
@@ -142,6 +143,31 @@ func (u *TownUser) Insert(db *sql.DB) (err error) {
 	return tx.Commit()
 }
 
+// TODO: really we should have like GetUser or something. but i don't want
+// to have to populate the struct to do this operation for now ~equa
+func RenameUser(db *sql.DB, old_name string, new_name string) (err error) {
+	stmt, err := db.Prepare(`UPDATE users SET username = ? WHERE username = ?`)
+	if err != nil {
+		return err
+	}
+
+	result, err := stmt.Exec(new_name, old_name)
+	if err != nil {
+		return err
+	}
+
+	rows, err := result.RowsAffected()
+	if err != nil {
+		return err
+	}
+
+	if rows == 0 {
+		return fmt.Errorf("couldn't find user")
+	}
+
+	return nil
+}
+
 func ConnectDB() (*sql.DB, error) {
 	db, err := sql.Open("sqlite3", dsn)
 	if err != nil {