Make wellknown-path a config variable

generate.py

 parser.add_argument('--trusted-cert-path', help='Path to use for trusted CA certificate. Use "%s" for hostname', default='/letsencrypt/certs/%s/chain.pem')
 parser.add_argument('--cert-path', help='Path to use for certificates. Use "%s" for hostname', default='/letsencrypt/certs/%s/fullchain.pem')
 parser.add_argument('--cert-key-path', help='Path to use for certificate private keys. Use "%s" for hostname', default='/letsencrypt/certs/%s/privkey.pem')
+parser.add_argument('--wellknown-path', help='Path to use for wellknown directory for http-01 challenge.', default='/letsencrypt/well-known/')
 args = parser.parse_args()
 
 jinja_env = jinja2.Environment(loader=jinja2.FileSystemLoader('/'))
   if wroteConfig or len(services) > 0 or not os.path.isfile('/nginx-config/vhosts.conf'):
     with open('/nginx-config/vhosts.conf', 'w') as f:
       print('Writing vhosts.conf...', flush=True)
-      f.write(template.render(services=services))
+      f.write(template.render(services=services, wellknown_path=args.wellknown_path))
       wroteConfig = True;
     print('Done writing config.', flush=True)
   else:

nginx.tpl

     # From https://community.letsencrypt.org/t/how-to-nginx-configuration-to-enable-acme-challenge-support-on-all-http-virtual-hosts/5622
     location ^~ /.well-known/acme-challenge/ {
         default_type "text/plain";
-        alias /letsencrypt/well-known/;
+        alias {{ wellknown_path }};
     }
 
     # Hide /acme-challenge subdirectory and return 404 on all requests.