openssl s_client -showcerts -servername servername -connect servername:443 > /tmp/cacert.pem
openssl x509 -in /tmp/cacert.pem -text
curl --cacert /tmp/cacert.pem -d '{"a":"b"}' https://servername/test
openssl s_client -showcerts -servername servername -connect servername:443 > /tmp/cacert.pem
openssl x509 -in /tmp/cacert.pem -text
curl --cacert /tmp/cacert.pem -d '{"a":"b"}' https://servername/test