This snippet is a cloud-init to prepare kubernetes nodes and masters before the kubeadm init script. just boring work of apt and users

cloud-init-kubernetes.yaml

users:
  - default
  - name: ubuntu
    gecos: Ubuntu
    sudo: ALL=(ALL) NOPASSWD:ALL
    groups: users, admin, docker
    shell: /bin/bash
    ssh_import_id: None
    lock_passwd: true
    ssh_authorized_keys:
      - ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDG0U7+ofHS17yk9k9eE0LvPElIQEHpuCoVOHtzy+kRv2LAblw+KyxIBUvjspOUX2gIx4+i3azUXhnI5P90lJWPacsRpXgQKiu1KejloWSnlY+gNkPrs2V+eglMQ2KW13H1v659Kq0C3/IhRtNFwDtM3yWhcFS+XeD5V2sRzB/8KifXz7Fbdl61Ky8tKwguwlq2WTaewLAeL6lO/8s4h+j/UKOIS7TvvQx7fJzydv2CZlUH0+PuFQbv6iDRy6dSSlkYXDX6Rv289M+5bM+eT02XnAdJO2ybXZz0oZk0fcAzid+LxkQ2/1/WqwE33R+NiZt+VDSfIXSgJKsG1r0Rkv2H andretapxure@MacBook-Air-de-Andre-2.local

apt:
  sources:
    kubernetes:
      source: "deb http://apt.kubernetes.io/ kubernetes-xenial main"
      # key from https://packages.cloud.google.com/apt/doc/apt-key.gpg
      key: |
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        CgsEFgIDAQAAJr4IAM5lgJ2CTkTRu2iw+tFwb90viLR6W0N1CiSPUwi1gjEKMr5r
        0aimBi6FXiHTuX7RIldSNynkypkZrNAmTMM8SU+sri7R68CFTpSgAvW8qlnlv2iw
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        Z1WOHe0j
        =ZJJ5
        -----END PGP PUBLIC KEY BLOCK-----
package_update: true
package_upgrade: true
packages:
#  - avahi-daemon
  - docker.io
  - apt-transport-https
  - kubelet=1.19.9-00
  - kubeadm=1.19.9-00
  - kubernetes-cni
write_files:
  - content: "{\"exec-opts\": [\"native.cgroupdriver=systemd\"]}"
    path:  /etc/docker/daemon.json
    owner: docker:docker
    append: true
runcmd:
  - sudo systemctl enable docker.service
  - sudo systemctl daemon-reload
  - sudo systemctl restart docker.service
#sudo kubeadm init --apiserver-advertise-address=172.16.29.80 --kubernetes-version stable-1.19