Ok, I managed to find a solution

ports: - ${PORT}:443 volumes: - jsreport:/jsreport - certs:/certs environment: httpsPort: 443 certificate_key: /certs/${SSL_KEY} certificate_cert: /certs/${SSL_CERT}

I needed to specify the certs directory from the root...
And the config path needed a ' _ ' not a ' . ' , I don't know how I made that assumption