kubespray/roles/kubernetes/node/templates/openssl.conf.j2

[req]
req_extensions = v3_req
distinguished_name = req_distinguished_name
[req_distinguished_name]
[ v3_req ]
basicConstraints = CA:FALSE
keyUsage = nonRepudiation, digitalSignature, keyEncipherment
subjectAltName = @alt_names
[alt_names]
DNS.1 = kubernetes
DNS.2 = kubernetes.default
DNS.3 = kubernetes.default.svc.{{ dns_domain }}
{% if loadbalancer_apiserver is defined  and apiserver_loadbalancer_domain_name is defined %}
DNS.4 = {{ apiserver_loadbalancer_domain_name }}
{% endif %}
{% for host in groups['kube-master'] %}
IP.{{ loop.index }} = {{ hostvars[host]['ip'] | default(hostvars[host]['ansible_default_ipv4']['address']) }}
{% endfor %}
{% set idx =  groups['kube-master'] | length | int + 1 %}
IP.{{ idx | string }} = {{ kube_apiserver_ip }}