Compare Docker container runtimes and check the available resources, the kernel version and the visibility of the kernel files (made for a youtube video))

docker-container-runtime-test.sh

#!/usr/bin/env bash

set -eu -o pipefail

runtimes=(Host runc runsc kata)

YELLOW_START='\033[1;33m'
YELLOW_END='\033[0m'

declare -A COMMANDS=(
  [cpus]='nproc'
  [memory]='free | grep "Mem" | awk "{print \$2}"'
  [kernel]='uname -nrv'
  [filesystem]='ls /boot | awk "/vmlinuz-/" | sort -r | head -n1'
)

function runtime_run() {
  local mode="$1"
  local runtime="$2"
  local command="$3"

  if [[ "$runtime" != "Host" ]]; then
    command="docker run --rm --runtime $runtime ubuntu $command"
  fi

  case "$mode" in
    echo)   echo "$command" ;;
    yellow) echo -e "${YELLOW_START}${command}${YELLOW_END}" ;;
    exec)   eval "$command" ;;
    *) >&2  echo "Invalid mode: $mode. Valid modes: echo, exec"; return 1
  esac
}

function showresult() {
  local runtime="$1"
  local label="$2"
  local command="$3"

  runtime_run yellow "$runtime" "$command"
  echo -n "$label: "
  runtime_run exec "$runtime" "$command"
}

labels=("$@")
if (( "${#labels[@]}" == 0 )); then
  for label in "${!COMMANDS[@]}"; do
    labels+=("$label")
  done
fi

for label in "${labels[@]}"; do
  for runtime in "${runtimes[@]}"; do
    showresult "$runtime" "$label" "${COMMANDS[$label]}"
    echo
  done
done