- hosts: all
  become: yes
  tasks:
   - name: install Docker
     yum:
       name: docker
       state: present
       update_cache: true
  
   - name: start Docker
     service:
       name: docker
       enabled: yes
       state: started
       
   - name: Stop and disable firewalld.
     service:
       name: firewalld
       state: stopped
       enabled: False       
  
   - name: disable SELinux
     command: setenforce 0
  
   - name: disable SELinux on reboot
     selinux:
       state: disabled

   - name: Remove swapfile from /etc/fstab
     mount:
       name: swap
       fstype: swap
       state: absent
       
   - name: Disable swap
     command: swapoff -a
     when: ansible_swaptotal_mb > 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: 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

   - name: install kubectl
     yum:
       name: kubectl
       state: present
       allow_downgrade: true

- hosts: master
  become: yes
  tasks:
    - name: initialize the cluster
      shell: kubeadm init
  
    - name: create .kube directory
      become: yes
      become_user: root
      file:
        path: $HOME/.kube
        state: directory
        mode: 0755
  
    - name: copy admin.conf to user's kube config
      copy:
        src: /etc/kubernetes/admin.conf
        dest: /root/.kube/config
        remote_src: yes
        owner: root
    
    - name: install Pod network
      become: yes
      become_user: root
      shell: kubectl apply -f https://raw.githubusercontent.com/thinkub/ansible-k8s-cluster/master/flannel.yml
      args:
        chdir: $HOME
        creates: pod_network_setup.txt

- hosts: master
  become: yes
  gather_facts: false
  tasks:
    - name: get join command
      shell: kubeadm token create --print-join-command
      register: join_command_raw
  
    - name: set join command
      set_fact:
        join_command: "{{ join_command_raw.stdout_lines[0] }}"
  
  
- hosts: nodes
  become: yes
  tasks:
    - name: join cluster
      shell: "{{ hostvars['master'].join_command }} --ignore-preflight-errors all  >> node_joined.txt"
      args:
        chdir: $HOME
        creates: node_joined.txt