Script for constraining containers on media box. This one is used on a 6c/12t CPU - adjust to your needs.

restrict.sh

#!/bin/bash

errexit() {
  local err=$?
  set +o xtrace
  local code="${1:-1}"
  echo "Error in ${BASH_SOURCE[1]}:${BASH_LINENO[0]}. '${BASH_COMMAND}' exited with status $err"
  # Print out the stack trace described by $function_stack
  if [ ${#FUNCNAME[@]} -gt 2 ]
  then
    echo "Call tree:"
    for ((i=1;i<${#FUNCNAME[@]}-1;i++))
    do
      echo " $i: ${BASH_SOURCE[$i+1]}:${BASH_LINENO[$i]} ${FUNCNAME[$i]}(...)"
    done
  fi
  echo "Exiting with status ${code}"
  exit "${code}"
}

trap 'errexit' ERR

set -o errtrace

docker update --memory "8gb" --cpuset-cpus=2,6 plex || true

declare -a low_pri_containers=("nzbget" "jackett" "sonarr" "radarr" "rutorrent" "postgres12" "wikijs-db" "wikijs_blockdiag_1" "wikijs_kroki_1" "wikijs_mermaid_1" "wikijs_wiki_1")

for container in "${low_pri_containers[@]}"; do
  echo "[lowpri]: restricting $container"
  docker update "$container" --memory "2gb" --cpus=2 --cpuset-cpus=7,11 || true
done

Pleaase don't allocate cpu0 if you use this. The schedulers like to use it for network.