This container uses dehydrated to automatically obtain SSL certs from Let’s Encrypt.
You will need a webserver that will serve the challenge responses when queried by Let’s Encrypt, such as my service-nginx container.
Multiple domains, as well as SANs, are supported. Certificates will be renewed automatically, and obtained automatically as soon as new domains are added.
In order to issue certificates with Let’s Encrypt, you must agree to the
Let’s Encrypt terms of service. You can do this by running the command
/dehydrated --register --accept-terms
from within the container.
For ease of automation, you can define the ACCEPT_CA_TERMS
env var
(with any non-empty value) to automatically accept the terms. Be warned
that doing so will automatically accept any future changes to the terms
of service.
The container defines one volume at /letsencrypt
, and expects there to be
a list of domains in /letsencrypt/domains.txt
. Certificates are output to
/letsencrypt/certs/{domain}
.
domains.txt should contain one line per certificate. If you want alternate names on the cert, these should be listed after the primary domain. e.g.
example.com www.example.com
admin.example.com
This will request two certificates: one for example.com with a SAN of www.example.com, and a separate one for admin.example.com.
The container uses inotify to monitor the domains.txt file for changes, so you can update it while the container is running and changes will be automatically applied.
To verify that you own the domain, a webserver must be listening for
requests and serve a unique file under the /.well-known/acme-challenge
directory. The responses for these files are written by this container
to /letsencrypt/well-known
.
For testing purposes, you can set the STAGING
environment variable to
a non-empty value. This will use the Let’s Encrypt staging server, which
has much more relaxed limits.
You should pass in a contact e-mail address by setting the EMAIL
env var.
This is passed on to Let’s Encrypt, and may be used for important service
announcements.
By default this container uses Eliptic Curve keys. You can override this
behaviour by setting the ALGORITHM
environment variable. Dehydrated
supports the following algorithms: rsa
, prime256v1
and secp384r1
.