I tested the acme-dns module and it works. 
I followed the instructions from the wiki.
Again I had to use another domain than my servers domain name so I edited /etc/e-smith/templates/etc/acme-dns/config.cfg/10general and did config setprop acme-dns Domain mydomain.com:
my $dmn = ${'acme-dns'}{'Domain'} || $DomainName;
my $domain = "acme.".$dmn;
my $nsname = "ns1.acme.".$dmn;
my $nsadmin = "admin.".$dmn;
my $domaindot = "acme.".$dmn.".";
my $nsnamedot = "ns1.acme.".$dmn.".";
my $ns2namedot = "ns2.acme.".$dmn.".";
HTTP worked without an error, I changed to HTTPS and after executing following command the cert is renewed but I got an error (I added the -v switch to get more output).
certbot certonly --manual --manual-auth-hook /etc/letsencrypt/acme-dns-auth.py --preferred-challenges dns --debug-challenges --post-hook "/sbin/e-smith/signal-event certificate-update" -d mydomain.com -v
Error:
Hook command "/etc/letsencrypt/acme-dns-auth.py" returned error code 1
Error output from acme-dns-auth.py:
Traceback (most recent call last):
File "/etc/letsencrypt/acme-dns-auth.py", line 154, in <module>
client.update_txt_record(account, VALIDATION_TOKEN)
File "/etc/letsencrypt/acme-dns-auth.py", line 65, in update_txt_record
data=json.dumps(update))
File "/usr/lib/python2.7/site-packages/requests/api.py", line 108, in post
return request('post', url, data=data, json=json, **kwargs)
File "/usr/lib/python2.7/site-packages/requests/api.py", line 50, in request
response = session.request(method=method, url=url, **kwargs)
File "/usr/lib/python2.7/site-packages/requests/sessions.py", line 464, in req uest
resp = self.send(prep, **send_kwargs)
File "/usr/lib/python2.7/site-packages/requests/sessions.py", line 576, in sen d
r = adapter.send(request, **kwargs)
File "/usr/lib/python2.7/site-packages/requests/adapters.py", line 431, in sen d
raise SSLError(e, request=request)
requests.exceptions.SSLError: [SSL: UNKNOWN_PROTOCOL] unknown protocol (_ssl.c:5 79)
It worked so maybe the error could be ignored?