Intermediate certificates are issued by TLS providers who themselves are
an intermediate of a certificate in the trust store. Therefore, to prove
the chain of trust is valid, you need to include their certificate as
well as yours when you send your certificate to the client.
Contrary to what I said in issue #683, distribution can handle these
certificate bundles like nginx. As discussed in #docker-distribution,
I have updated the deployment documentation (which recommends the use of
a TLS certificate from a provider) to include instructions on how to
handle the intermediate certificate when a user is configuring
distribution.
Signed-off-by: Luke Carpenter <x@rubynerd.net>