celeryctl: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/celeryctl - from package: python-celery

You may install the required package with command yum install {package}

Error in other languages:
celeryctl: bevel nie gevind nie
celeryctl: comandă negăsită
celeryctl: comando não encontrado
celeryctl: commande introuvable
celeryctl: command not found
celeryctl: käsku ei ole
celeryctl: không tìm thấy lệnh
celeryctl: komanda nerasta
celeryctl: Kommando nicht gefunden.
celeryctl: kommandot finns inte
celeryctl: komut yok
celeryctl: nie znaleziono polecenia
celeryctl: níor aimsíodh an t-ordú
celeryctl: no se encontró la orden
celeryctl: no s'ha trobat l'ordre
celeryctl: opdracht niet gevonden
celeryctl: parancs nem található
celeryctl: perintah tidak ditemukan
celeryctl: príkaz nenájdený
celeryctl: příkaz nenalezen
celeryctl: команда не найдена
celeryctl: командата не е открита
celeryctl: 命令找不到
celeryctl: コマンドが見つかりません