This change contains the roles and testing for deploying certificates
on hosts using letsencrypt with domain authentication.
From a top level, the process is implemented in the roles as follows:
1) letsencrypt-acme-sh-install
This role installs the acme.sh tool on hosts in the letsencrypt
group, along with a small custom driver script to help parse output
that is used by later roles.
2) letsencrypt-request-certs
This role runs on each host, and reads a host variable describing
the certificates required. It uses the acme.sh tool (via the
driver) to request the certificates from letsencrypt. It populates
a global Ansible variable with the authentication TXT records
required.
If the certificate exists on the host and is not within the renewal
period, it should do nothing.
3) letsencrypt-install-txt-record
This role runs on the adns server. It installs the TXT records
generated in step 2 to the acme.opendev.org domain and then
refreshes the server. Hosts wanting certificates will have
pre-provisioned CNAME records for _acme-challenge.host.opendev.org
pointing to acme.opendev.org.
4) letsencrypt-create-certs
This role runs on each host, reading the same variable as in step
2. However this time the acme.sh tool is run to authenticate and
create the certificates, which should now work correctly via the
TXT records from step 3. After this, the host will have the
full certificate material.
Testing is added via testinfra. For testing purposes requests are
made to the staging letsencrypt servers and a self-signed certificate
is provisioned in step 4 (as the authentication is not available
during CI). We test that the DNS TXT records are created locally on
the CI adns server, however.
Related-Spec: https://review.openstack.org/587283
Change-Id: I1f66da614751a29cc565b37cdc9ff34d70fdfd3f
afd907c16d