kiwi-cron/libexec/kiwi-cron/create_schedule

#!/bin/sh

cs_every="${1:-1}"
cs_units="${2}"
cs_command="${3}"

if [ "${cs_every}" -eq 1 ]; then
  cs_every=""
else
  cs_every="/${cs_every}"
fi

# generate valid random schedule values
# generally, "nighttime" and "weekend" will be preferred.

# shellcheck disable=SC3028 # RANDOM is defined in alpine's /bin/sh
cs_rand_min=$(( RANDOM % 60 ))

# shellcheck disable=SC3028
# cs_rand_hour=$(( RANDOM % 24 ))
cs_rand_hour=$(( (21 + RANDOM % 7) % 24 ))

# shellcheck disable=SC3028
cs_rand_day=$(( RANDOM % 31 + 1 ))

# shellcheck disable=SC3028
# cs_rand_weekday=$(( RANDOM % 7 ))
cs_rand_weekday=$(( (6 + RANDOM % 2) % 7 ))

# shellcheck disable=SC3028
# cs_rand_month=$(( RANDOM % 12 + 1 ))
cs_rand_month=$(( RANDOM % 2 + 1 ))

case "${cs_units}" in
  minute)
    echo "*${cs_every}" "*" "*" "*" "*" "${cs_command}" 
    ;;
  hour)
    echo "${cs_rand_min}" "*${cs_every}" "*" "*" "*" "${cs_command}" 
    ;;
  day)
    echo "${cs_rand_min}" "${cs_rand_hour}" "*${cs_every}" "*" "*" "${cs_command}" 
    ;;
  week)
    echo "${cs_rand_min}" "${cs_rand_hour}" "*" "*" "${cs_rand_weekday}" "${cs_command}" 
    ;;
  month)
    echo "${cs_rand_min}" "${cs_rand_hour}" "${cs_rand_day}" "*${cs_every}" "*" "${cs_command}" 
    ;;
  year)
    echo "${cs_rand_min}" "${cs_rand_hour}" "${cs_rand_day}" "${cs_rand_month}" "*" "${cs_command}" 
    ;;
esac