kubespray/roles/network_plugin/calico/templates/network-environment.j2

# This host's IPv4 address (the source IP address used to reach other nodes
# in the Kubernetes cluster).
DEFAULT_IPV4={{ip | default(ansible_default_ipv4.address) }}

# The Kubernetes master IP
KUBERNETES_MASTER={{ hostvars[groups['kube-master'][0]]['access_ip'] | default(hostvars[groups['kube-master'][0]]['ip'] | default(hostvars[groups['kube-master'][0]]['ansible_default_ipv4']['address'])) }}

# IP and port of etcd instance used by Calico
ETCD_AUTHORITY=127.0.0.1:2379