docker: document cmdeploy dns in docker containers

Author: missytake

cmdeploy/src/cmdeploy/cmdeploy.py

@@ -128,7 +128,7 @@ def dns_cmd_options(parser):
     parser.add_argument(
         "--ssh-host",
         dest="ssh_host",
-        help="Run the DNS queries on 'localhost', via 'docker', or on a specific SSH host",
+        help="Run the DNS queries on 'localhost', in the chatmail 'docker' container, or on a specific SSH host",
     )
 
 

docs/DOCKER_INSTALLATION_EN.md

@@ -82,6 +82,11 @@ docker compose logs -f chatmail # view container logs, press CTRL+C to exit
 
 8. After installation is complete, you can open `https://<your_domain_name>` in your browser.
 
+9. To send messages to other chatmail relays,
+   you need to set additional DNS records.
+   Run `docker exec chatmail scripts/cmdeploy.sh dns --ssh-host localhost`
+   to see recommended DNS records and check whether they are correct.
+
 ## Using custom files
 
 When using Docker, you can apply modified configuration files to make the installation more personalized. This is usually needed for the `www/src` section so that the Chatmail landing page is customized to your taste, but it can be used for any other cases as well.