It creates SSL certificates that are signed by either a custom CA, CA with an intermediate, or self-signed. A custom CA or intermediate certificate that already exists can also be used to sign the certificates.
To create certifcates:
docker run --rm -ti bradkwadsworth/dummy-certs
To use existing CA and intermediate certificates:
docker run --rm -ti \
-v /path/to/certs/dir:/certs \
bradkwadsworth/dummy-certs
To pass Subject Alternative Names set the SAN environment variable
docker run --rm -ti \
-e SAN='DNS:somehost,DNS:anotherhost,IP:1.2.3.4' \
bradkwadsworth/dummy-certs