https://devcenter.heroku.com/articles/csr
openssl genrsa -des3 -out server.orig.key 2048
openssl rsa -in server.orig.key -out server.key
openssl req -new -key server.key -out server.csr
- Select Apache (2.0) as the web server when downloading
- Unpack download into same dir as keys above
- Combine root CA certificate
cat mydomain.com.crt gd_bundle.crt > final.crt
heroku certs:add final.crt server.key
# or if you're updating an existing
heroku certs:update final.crt server.key