rpmkeys: 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 Debian possible default full paths are:

/usr/bin/rpmkeys - from package: rpm

You may install the required package with command apt-get install {package}

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