To generate the SAN certificate.
openssl req \
-newkey rsa:4096 \
-days 3650 \
-nodes \
-x509 \
-subj "/C=US/ST=Distributed/L=Cloud/O=Cluster/CN=*.sfgroups.com" \
-extensions SAN \
-config <( cat /etc/pki/tls/openssl.cnf \
<(printf "[SAN]\nsubjectAltName='DNS.1:*.sfgroups.com,DNS.2:localhost,DNS.3:192.168.16.15'")) \
-keyout private_key.pem \
-out server.crt