kubespray/roles/kubernetes/preinstall/tasks/verify-settings.yml

---
- name: Stop if ansible version is too low
  assert:
    that:
      - ansible_version.full|version_compare('2.3.0', '>=')
  run_once: yes

- name: Stop if non systemd OS type
  assert:
    that: ansible_service_mgr == "systemd"
  ignore_errors: "{{ ignore_assert_errors }}"

- name: Stop if unknown OS
  assert:
    that: ansible_distribution in ['RedHat', 'CentOS', 'Fedora', 'Ubuntu', 'Debian', 'CoreOS', 'Container Linux by CoreOS', 'openSUSE Leap', 'openSUSE Tumbleweed']
  ignore_errors: "{{ ignore_assert_errors }}"

- name: Stop if unknown network plugin
  assert:
    that: kube_network_plugin in ['calico', 'canal', 'flannel', 'weave', 'cloud', 'cilium', 'contiv']
  when: kube_network_plugin is defined
  ignore_errors: "{{ ignore_assert_errors }}"

- name: Stop if incompatible network plugin and cloudprovider
  assert:
    that: kube_network_plugin != 'calico'
    msg: "Azure and Calico are not compatible. See https://github.com/projectcalico/calicoctl/issues/949 for details."
  when: cloud_provider is defined and cloud_provider == 'azure'
  ignore_errors: "{{ ignore_assert_errors }}"

# simplify this items-list when   https://github.com/ansible/ansible/issues/15753  is resolved
- name: "Stop if known booleans are set as strings (Use JSON format on CLI: -e \"{'key': true }\")"
  assert:
    that: item.value|type_debug == 'bool'
    msg: "{{item.value}} isn't a bool"
  run_once: yes
  with_items:
    - { name: kubeadm_enabled, value: "{{ kubeadm_enabled }}" }
    - { name: download_run_once, value: "{{ download_run_once }}" }
    - { name: deploy_netchecker, value: "{{ deploy_netchecker }}" }
    - { name: download_always_pull, value: "{{ download_always_pull }}" }
    - { name: efk_enabled, value: "{{ efk_enabled }}" }
    - { name: helm_enabled, value: "{{ helm_enabled }}" }
    - { name: openstack_lbaas_enabled, value: "{{ openstack_lbaas_enabled }}" }
  ignore_errors: "{{ ignore_assert_errors }}"

- name: Stop if even number of etcd hosts
  assert:
    that: groups.etcd|length is not divisibleby 2
  ignore_errors: "{{ ignore_assert_errors }}"

- name: Stop if memory is too small for masters
  assert:
    that: ansible_memtotal_mb >= 1500
  ignore_errors: "{{ ignore_assert_errors }}"
  when: inventory_hostname in groups['kube-master']

- name: Stop if memory is too small for nodes
  assert:
    that: ansible_memtotal_mb >= 1024
  ignore_errors: "{{ ignore_assert_errors }}"
  when: inventory_hostname in groups['kube-node']

# This assertion will fail on the safe side: One can indeed schedule more pods
# on a node than the CIDR-range has space for when additional pods use the host
# network namespace. It is impossible to ascertain the number of such pods at
# provisioning time, so to establish a guarantee, we factor these out.
# NOTICE: the check blatantly ignores the inet6-case
- name: Guarantee that enough network address space is available for all pods
  assert:
    that: "{{ kubelet_max_pods <= (2 ** (32 - kube_network_node_prefix)) - 2 }}"
    msg: "Do not schedule more pods on a node than inet addresses are available."
  ignore_errors: "{{ ignore_assert_errors }}"
  when:
    - inventory_hostname in groups['kube-node']
    - kube_network_node_prefix is defined

- name: Stop if ip var does not match local ips
  assert:
    that: ip in ansible_all_ipv4_addresses
  ignore_errors: "{{ ignore_assert_errors }}"
  when: ip is defined

- name: Stop if access_ip is not pingable
  command: ping -c1 {{ access_ip }}
  when: access_ip is defined
  ignore_errors: "{{ ignore_assert_errors }}"

- name: Stop if swap enabled
  assert:
    that: ansible_swaptotal_mb == 0
  when: kubelet_fail_swap_on|default(true)
  ignore_errors: "{{ ignore_assert_errors }}"

- name: Stop if RBAC is not enabled when dashboard is enabled
  assert:
    that: rbac_enabled
  when: dashboard_enabled
  ignore_errors: "{{ ignore_assert_errors }}"

- name: Stop if RBAC and anonymous-auth are not enabled when insecure port is disabled
  assert:
    that: rbac_enabled and kube_api_anonymous_auth
  when: kube_apiserver_insecure_port == 0
  ignore_errors: "{{ ignore_assert_errors }}"

- name: Stop if kernel version is too low
  assert:
    that: ansible_kernel.split('-')[0]|version_compare('4.8', '>=')
  when: kube_network_plugin == 'cilium'
  ignore_errors: "{{ ignore_assert_errors }}"