Multinode Kubernetes cluster on CentOS with Ansible

initial_config.yaml

- hosts: all
  become: yes
  tasks:
   - name: disable SELinux
     command: setenforce 0

   - name: ensure net.bridge.bridge-nf-call-ip6tables is set to 1
     sysctl:
      name: net.bridge.bridge-nf-call-ip6tables
      value: 1
      state: present

   - name: ensure net.bridge.bridge-nf-call-iptables is set to 1
     sysctl:
      name: net.bridge.bridge-nf-call-iptables
      value: 1
      state: present

   - name: disable SELinux on reboot
     selinux:
       state: disabled  

   - name: install Docker
     yum:
       name: docker
       state: present
       update_cache: true

   - name: set devicemapper as storage option for Docker
     lineinfile:
       path: /etc/sysconfig/docker-storage
       regexp: '^DOCKER_STORAGE_OPTIONS=.*?$'
       line: 'DOCKER_STORAGE_OPTIONS="--storage-driver devicemapper"'

   - name: set devicemapper as storage driver for Docker
     lineinfile:
       path: /etc/sysconfig/docker-storage-setup
       regexp: '^STORAGE_DRIVER=.*?$'
       line: 'STORAGE_DRIVER=devicemapper'

   - name: start Docker
     service:
       name: docker
       state: started

   - name: add Kubernetes' YUM repository
     yum_repository:
      name: Kubernetes
      description: Kubernetes YUM repository
      baseurl: https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
      gpgkey: https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
      gpgcheck: yes

   - name: install kubelet
     yum:
        name: kubelet
        state: present
        update_cache: true

   - name: install kubeadm
     yum:
        name: kubeadm
        state: present

   - name: start kubelet
     service:
       name: kubelet
       enabled: yes
       state: started

- hosts: master
  become: yes
  tasks:
   - name: install kubectl
     yum:
        name: kubectl
        state: present