stand up a kubernetes cluster on a host - shell or yaml for ansible - from

create-kubernetes-cluster.sh

#!/bin/bash

# originally from: https://github.com/kubernetes/kubernetes/issues/106464#issuecomment-1142563656

# edited by Brian Onn https://github.com/brianonn

# see also
# https://kubernetes.io/docs/setup/production-environment/container-runtimes/#containerd-systemd

# works on debian 10, maybe 11 ? maybe 9 ?
#
## TODO test all the above
## 

swapoff --all

cat <<EOF | tee /etc/modules-load.d/k8s.conf
overlay
br_netfilter
EOF
modprobe overlay
modprobe br_netfilter
cat <<EOF | tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables  = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.ipv4.ip_forward                 = 1
EOF
sysctl --system

wget https://github.com/containerd/containerd/releases/download/v1.6.4/containerd-1.6.4-linux-amd64.tar.gz
tar Cxzvf /usr/local containerd-1.6.4-linux-amd64.tar.gz

mkdir /etc/containerd/
containerd config default > /etc/containerd/config.toml
sed -i 's|SystemdCgroup = false|SystemdCgroup = true|' /etc/containerd/config.toml

wget https://github.com/opencontainers/runc/releases/download/v1.1.2/runc.amd64
install -m 755 runc.amd64 /usr/local/sbin/runc

wget https://github.com/containernetworking/plugins/releases/download/v1.1.1/cni-plugins-linux-amd64-v1.1.1.tgz
mkdir --parents /opt/cni/bin
tar Cxzvf /opt/cni/bin cni-plugins-linux-amd64-v1.1.1.tgz

wget https://raw.githubusercontent.com/containerd/containerd/main/containerd.service --output-document=/etc/systemd/system/containerd.service
systemctl daemon-reload
systemctl enable --now containerd

wget https://github.com/flannel-io/flannel/releases/download/v0.18.0/flannel-v0.18.0-linux-amd64.tar.gz
mkdir /opt/bin
tar --directory=/opt/bin --extract --gzip --file=flannel-v0.18.0-linux-amd64.tar.gz flanneld

apt-get update && apt-get install -y apt-transport-https ca-certificates curl
curl -fsSLo /usr/share/keyrings/kubernetes-archive-keyring.gpg https://packages.cloud.google.com/apt/doc/apt-key.gpg
echo "deb [signed-by=/usr/share/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | tee /etc/apt/sources.list.d/kubernetes.list
apt-get update
apt-get install -y kubelet kubeadm kubectl
apt-mark hold kubelet kubeadm kubectl

kubeadm init --pod-network-cidr=10.244.0.0/16
echo 'KUBECONFIG=/etc/kubernetes/admin.conf' >> /etc/environment
export KUBECONFIG=/etc/kubernetes/admin.conf
kubectl apply -f https://raw.githubusercontent.com/flannel-io/flannel/master/Documentation/kube-flannel.yml
kubectl get pods --all-namespaces

create-kubernetes-cluster.yaml

---
# from: https://github.com/kubernetes/kubernetes/issues/106464#issuecomment-1143691262
#
# edited by Brian Onn https://github.com/brianonn
#
#
- hosts: all
  become: true
  tasks:
  - name: disable swap
    shell: |
      sudo swapoff -a
      sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
  
  - name: Add modules conf for k8s
    blockinfile:
      path: "/etc/modules-load.d/k8s.conf"
      block: |
            overlay
            br_netfilter
      create: yes

  - name: Add modules
    community.general.modprobe:
      name: "{{ item }}"
      state: present
    with_items:
      - overlay
      - br_netfilter

  - name: Set sysctl file and reload
    ansible.posix.sysctl:
      name: "{{ item }}"
      value: '1'
      state: present
      reload: yes
    with_items:
      - net.ipv4.ip_forward
      - net.bridge.bridge-nf-call-iptables
      - net.bridge.bridge-nf-call-ip6tables

  - name: Download containerd package
    get_url:
      url: https://github.com/containerd/containerd/releases/download/v1.6.4/containerd-1.6.4-linux-amd64.tar.gz
      dest: /home/vagrant/containerd-1.6.4-linux-amd64.tar.gz
      mode: '0777'
  
  - name: Extract containerd
    ansible.builtin.unarchive:
      src: /home/vagrant/containerd-1.6.4-linux-amd64.tar.gz
      dest: /usr/local
      remote_src: yes
  
  - name: Create containerd config.toml
    lineinfile:
      line: ""
      path: "/etc/containerd/config.toml"
      create: yes

  - name: Populate containerd config
    shell: containerd config default | tee /etc/containerd/config.toml
  
  - name: Set SystemdCgroup to true in containerd config
    replace:
      path: /etc/containerd/config.toml
      regexp: "SystemdCgroup = false"
      replace: "SystemdCgroup = true"

  - name: Download runc package
    get_url:
      url: https://github.com/opencontainers/runc/releases/download/v1.1.2/runc.amd64
      dest: /home/vagrant/runc.amd64
      mode: '0777'
  
  - name: Install runc
    shell: install -m 755 /home/vagrant/runc.amd64 /usr/local/sbin/runc

  - name: Download cni plugin
    get_url:
      url: https://github.com/containernetworking/plugins/releases/download/v1.1.1/cni-plugins-linux-amd64-v1.1.1.tgz
      dest: /home/vagrant/cni-plugins-linux-amd64-v1.1.1.tgz
      mode: '0777'

  - name: Create /opt/cni/bin dir
    file:
      path: /opt/cni/bin
      state: directory

  - name: Extract cni plugin
    ansible.builtin.unarchive:
      src: /home/vagrant/cni-plugins-linux-amd64-v1.1.1.tgz
      dest: /opt/cni/bin
      remote_src: yes

  - name: Download containerd service
    get_url:
      url: https://raw.githubusercontent.com/containerd/containerd/main/containerd.service
      dest: /etc/systemd/system/containerd.service
      mode: '0777'
  
  - name: Issue daemon-reload to pick up config changes, restart containerd service
    ansible.builtin.systemd:
      state: restarted
      daemon_reload: yes
      name: containerd
  
  - name: Download flannel
    get_url:
      url: https://github.com/flannel-io/flannel/releases/download/v0.18.0/flannel-v0.18.0-linux-amd64.tar.gz
      dest: /home/vagrant/flannel-v0.18.0-linux-amd64.tar.gz
      mode: '0777'

  - name: Create /opt/bin dir
    file:
      path: /opt/bin
      state: directory

  - name: Extract flannel
    ansible.builtin.unarchive:
      src: /home/vagrant/flannel-v0.18.0-linux-amd64.tar.gz
      dest: /opt/bin
      remote_src: yes
    
  - name: Install packages that allow apt to be used over HTTPS
    apt:
      name: "{{ packages }}"
      state: present
      update_cache: yes
    vars:
      packages:
      - apt-transport-https
      - ca-certificates
      - curl

  - name: Add an apt signing key for Kubernetes
    apt_key:
      url: https://packages.cloud.google.com/apt/doc/apt-key.gpg
      state: present

  - name: Adding apt repository for Kubernetes
    apt_repository:
      repo: deb https://apt.kubernetes.io/ kubernetes-xenial main
      state: present
      filename: kubernetes.list

  - name: Install Kubernetes binaries
    apt: 
      name: "{{ packages }}"
      state: present
      update_cache: yes
    vars:
      packages:
        - kubelet 
        - kubeadm   
        - kubectl

  - name: Initialize the cluster
    shell: kubeadm init --pod-network-cidr=10.244.0.0/16

  - name: Create /home/vagrant/.kube dir
    file:
      path: /home/vagrant/.kube
      state: directory

  - name: Copies admin.conf to user's kube config
    copy:
      src: /etc/kubernetes/admin.conf
      dest: /home/vagrant/.kube/config
      remote_src: yes
      owner: vagrant

  - name:  Install flannel for k8s
    become: false
    command: kubectl apply -f https://raw.githubusercontent.com/flannel-io/flannel/master/Documentation/kube-flannel.yml