docker-htop.sh

#!/bin/bash

docker() {
  case "$1" in
    htop)
      local container="$2"
      if [ -z "$container" ]; then
        echo -e '"docker htop" requires at least 1 argument.\n'
        echo -e 'Usage:\n\tdocker htop CONTAINER [htop OPTIONS]'
        return 1
      fi
      shift 2
      local pid
      if pid="$(command docker inspect -f '{{.State.Pid}}' "$container")"; then
        nsenter -p -t "$pid" unshare --mount-proc htop "$@"
      fi
    ;;
    *)
      command docker "$@"
    ;;
  esac
}