[I was wrong - see _azâs reply below]
Thanks _az.
It seemed such an obvious question that there had to be an âofficialâ answer.
I tested the âmozillaâ âmodernâ config with the ssllabs online test : https://www.ssllabs.com/ssltest/index.html
=> the mozilla config leaves out the chain file
=> the ssllabs test wants it (without it, got a B, with it, an A+)
Might be worth recommending the âmozilla configâ it in the Letsencrypt documentation.
If you pass fullchain.pem to SSLCertificateFile in Apache 2.4.8 or newer, it will automatically deal with chaining the intermediate for you.
If you enter your Apache version into the Server Version field on the config generator, it will automatically adjust the configuration for you, to reflect the above.
Same thing with OpenSSL version and the ciphersuite selection.
This is an excerpt from the recommended config. Do I need the SSLCACertificateFile?
SSLCertificateFile /etc/letsencrypt/live/[dir]/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/[dir]/privkey.pem
# Uncomment the following directive when using client certificate authentication
# SSLCACertificateFile /path/to/ca_certs_for_client_authentication