docs: use ssh_host = localhost in getting started docs

remove mentions of the build machine / deployment server separation

doc/source/getting_started.rst

@@ -14,21 +14,14 @@ Minimal requirements and prerequisites
 
 You will need the following:
 
--  A Debian 12 **deployment server** with reachable SMTP/SUBMISSIONS/IMAPS/HTTPS ports.
+-  Control over a domain through a DNS provider of your choice.
+   (there is experimental support for :ref:`IP-only relays <iponly>`).
+
+-  A Debian 12 server with reachable SMTP/SUBMISSIONS/IMAPS/HTTPS ports.
    IPv6 is encouraged if available. Chatmail relay servers only require
    1GB RAM, one CPU, and perhaps 10GB storage for a few thousand active
    chatmail addresses.
 
--  A Linux or Unix **build machine** with key-based SSH access to the root
-   user of the deployment server.
-   You must add a passphrase-protected private key to your local ssh-agent because you
-   can’t type in your passphrase during deployment.
-   (An ed25519 private key is required due to an `upstream bug in
-   paramiko <https://github.com/paramiko/paramiko/issues/2191>`_)
-
--  Control over a domain through a DNS provider of your choice
-   (there is experimental support for :ref:`IP-only relays <iponly>`).
-
 
 .. _setup:
 
@@ -38,7 +31,7 @@ Setup with ``scripts/cmdeploy``
 We use ``chat.example.org`` as the chatmail domain in the following
 steps. Please substitute it with your own domain.
 
-1. Setup the initial DNS records for your deployment server.
+1. Setup the initial DNS records for your relay.
    The following is an example in the
    familiar BIND zone file format with a TTL of 1 hour (3600 seconds).
    Please substitute your domain and IP addresses.
@@ -58,22 +51,25 @@ steps. Please substitute it with your own domain.
       The ``mta-sts`` CNAME and ``_mta-sts`` TXT records
       are not needed for such domains.
 
-2. On your local PC, clone the repository and bootstrap the Python
+2. Login to the server with SSH, clone the repository and bootstrap the Python
    virtualenv.
 
    ::
 
+       ssh root@chat.example.org
        git clone https://github.com/chatmail/relay
        cd relay
        scripts/initenv.sh
 
-3. On your local build machine (PC), create a chatmail configuration file
+3. Then, create a chatmail configuration file
    ``chatmail.ini``:
 
    ::
 
        scripts/cmdeploy init chat.example.org  # <-- use your domain
 
+   .. note::
+
    To use self-signed TLS certificates
    instead of Let's Encrypt,
    use a domain name starting with ``_``
@@ -84,13 +80,7 @@ steps. Please substitute it with your own domain.
    See the :doc:`overview`
    for details on certificate provisioning.
 
-4. Verify that SSH root login to the deployment server server works:
-
-   ::
-
-       ssh root@chat.example.org  # <-- use your domain
-
-5. From your local build machine, setup and configure the remote deployment server:
+4. Now run the deployment script to install the relay to the server:
 
    ::
 
@@ -195,7 +185,7 @@ Disable automatic address creation
 --------------------------------------------------------
 
 If you need to stop address creation, e.g. because some script is wildly
-creating addresses, login with ssh to the deployment machine and run:
+creating addresses, login with ssh to the relay and run:
 
 ::
 
@@ -251,25 +241,3 @@ The deploy will verify that both files exist on the server.
    If you use such a setup, you must trigger the reload explicitly after renewal::
 
       systemctl start tls-cert-reload.service
-
-
-Migrating to a new build machine
-----------------------------------
-
-To move or add a build machine,
-clone the relay repository on the new build machine, and copy the ``chatmail.ini`` file from the old build machine.
-Make sure ``rsync`` is installed, then initialize the environment:
-
-::
-
-   ./scripts/initenv.sh
-
-Run safety checks before a new deployment:
-
-::
-
-   ./scripts/cmdeploy dns
-   ./scripts/cmdeploy status
-
-If you keep multiple build machines (ie laptop and desktop), keep ``chatmail.ini`` in sync between
-them.