Packer QEMU/KVM to build Kubernetes image

kubernetes.json

{
    "builders":[
        {
            "type": "qemu",
            "iso_url": "{{ user `image_url` }}",
            "iso_checksum": "{{ user `image_checksum` }}",
            "iso_checksum_type": "{{ user `image_checksum_type` }}",
            "format": "qcow2",
            "disk_image": true,
            "disk_size": "{{ user `disk_size` }}",
            "output_directory": "build",
            "disk_compression": true,
            "headless": true,
            "boot_command": [
                "<enter>"
            ],
            "accelerator": "kvm",
            "ssh_username": "{{ user `ssh_username` }}",
            "ssh_password": "{{ user `ssh_password` }}",
            "ssh_port": 22,
            "ssh_wait_timeout": "300s",
            "vm_name": "{{ user `vm_name` }}",
            "use_default_display": false,
            "qemuargs": [
                ["-m", "{{ user `memory` }}"],
                ["-smp", "cpus={{ user `cpus` }}"],
                ["-cdrom", "{{ user `cloud_init_image` }}"],
                ["-serial", "mon:stdio"]
            ]
      }
    ],
    "provisioners": [
      {
        "execute_command": "echo '{{ user `ssh_password` }}' | {{.Vars}} sudo -E -S bash -x '{{.Path}}'",
        "scripts": [
          "setup.sh"
        ],
        "type": "shell"
      },
      {
        "type": "shell",
        "inline": ["sudo sync"]
      }
    ],
    "variables": {
      "cpus": "2",
      "image_checksum": "2ca8b726be5bbd929fb5675372819f1471fc831d05b6b31444e10adc3a06a8d5",
      "image_checksum_type": "sha256",
      "image_url" : "https://cloud-images.ubuntu.com/minimal/releases/bionic/release/ubuntu-18.04-minimal-cloudimg-amd64.img",
      "cloud_init_image": "cloud-init.img",
      "disk_size": "8192",
      "memory": "2048M",
      "ssh_username": "ubuntu",
      "ssh_password": "P4s5W0rD",
      "vm_name": "kubernetes-{{timestamp}}.qcow2"
    }
}

setup.sh

#!/bin/bash -x

apt-get update && apt-get install -y \
  apt-transport-https ca-certificates curl software-properties-common

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -

add-apt-repository \
  "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) \
  stable"

apt-get update && apt-get install -y \
  containerd.io=1.2.10-3 \
  docker-ce=5:19.03.4~3-0~ubuntu-$(lsb_release -cs) \
  docker-ce-cli=5:19.03.4~3-0~ubuntu-$(lsb_release -cs)

cat > /etc/docker/daemon.json <<EOF
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2"
}
EOF

mkdir -p /etc/systemd/system/docker.service.d

systemctl daemon-reload
systemctl restart docker

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -

cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF

sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl

systemctl daemon-reload
systemctl restart kubelet

kubeadm config images pull

swapoff -a
apt autoclean
rm -Rf /var/cache/apt/*

userdata.cfg

#cloud-config
password: P4s5W0rD
ssh_pwauth: true
chpasswd:
  expire: false

locale: en_US.UTF-8
locale_configfile: /etc/default/locale