Update winery frontend documentation

docs/sysadm/data-silos/winery/procedures/frontends.rst

 .. _winery-proc-frontends:
 
-Frontends procedures
-====================
+Frontend procedures
+===================
 
 .. admonition:: Intended audience
    :class: important
 
    sysadm staff members
 
-Pacemaker maintenance mode
---------------------------
+PostgreSQL management
+---------------------
 
-In maintenance mode, pacemaker will not attempt to manage the service or switch the ips from one
-node to another.
+PostgreSQL is handled using the `patroni`_ high-availability template, with
+ `consul`_ as a distributed configuration store.
 
-.. _winery-pacemaker-maintenance:
+ .. _patroni: https://patroni.readthedocs.io/en/latest/
+ .. _consul: https://developer.hashicorp.com/consul/docs
 
-- Force the maintenance mode
-
-.. code-block:: shell
-
-   crm_attribute --name maintenance-mode --update true
-
-- Go back to the nominal mode
-
-.. code-block:: shell
-
-   crm_attribute --name maintenance-mode --delete
-
-- check the status
-
-Nominal mode:
-
-.. code-block:: shell
-
-   root@gloin001:~# crm status
-   Status of pacemakerd: 'Pacemaker is running' (last updated 2024-03-06 18:45:31 +01:00)
-   Cluster Summary:
-      * Stack: corosync
-      * Current DC: gloin001 (version 2.1.5-a3f44794f94) - MIXED-VERSION partition with quorum
-      * Last updated: Wed Mar  6 18:45:31 2024
-      * Last change:  Wed Mar  6 18:45:27 2024 by root via crm_attribute on gloin001
-      * 2 nodes configured
-      * 4 resource instances configured
-
-   Node List:
-      * Online: [ gloin001 gloin002 ]
-
-   Full List of Resources:
-      * r_vip_pub   (ocf:heartbeat:IPaddr2):         Started gloin001
-      * r_vip_ha    (ocf:heartbeat:IPaddr2):         Started gloin001
-      * Clone Set: ha_postgresql [r_postgresql] (promotable):
-         * Promoted: [ gloin001 ]
-         * Unpromoted: [ gloin002 ]
-..
-
-In maintenance:
-
-.. code-block:: shell
-
-   root@gloin001:~# crm status
-   Status of pacemakerd: 'Pacemaker is running' (last updated 2024-03-06 18:43:58 +01:00)
-   Cluster Summary:
-      * Stack: corosync
-      * Current DC: gloin001 (version 2.1.5-a3f44794f94) - MIXED-VERSION partition with quorum
-      * Last updated: Wed Mar  6 18:43:58 2024
-      * Last change:  Wed Mar  6 18:41:47 2024 by root via crm_attribute on gloin001
-      * 2 nodes configured
-      * 4 resource instances configured
-
-               *** Resource management is DISABLED ***
-   The cluster will not attempt to start, stop or recover services
-
-   Node List:
-      * Online: [ gloin001 gloin002 ]
-
-   Full List of Resources:
-      * r_vip_pub   (ocf:heartbeat:IPaddr2):         Started gloin001 (unmanaged)
-      * r_vip_ha    (ocf:heartbeat:IPaddr2):         Started gloin001 (unmanaged)
-      * Clone Set: ha_postgresql [r_postgresql] (promotable, unmanaged):
-         * r_postgresql      (ocf:heartbeat:pgsqlms):         Unpromoted gloin002 (unmanaged)
-         * r_postgresql      (ocf:heartbeat:pgsqlms):         Promoted gloin001 (unmanaged)
-
-
-Clear the pacemaker error status of a resource
-----------------------------------------------
-
-For example:
-
-.. code-block:: shell
-
-    crm_resource -r r_postgresql -H gloin002 -C
-
-
-Restore a postgresql secondary from the primary
------------------------------------------------
-
-- Activate the :ref:`pacemaker maintenance mode <winery-pacemaker-maintenance>`
-
-- Stop postgresql via pacemaker (here the postgresql on gloin002)
-
-.. code-block:: shell
-
-   crm --wait resource ban r_postgresql gloin002
-
-Check the postgresql logs to check the status
-
-If the postgresql doesn't stop, it can be force with:
-
-.. code-block:: shell
-
-   export VERSION=<version>
-   sudo -u postgres /usr/lib/postgresql/$VERSION/bin/pg_ctl -D /var/lib/postgresql/$VERSION/main stop
-
-
-- Delete or move the content of the postgresql data directory in ``/var/lib/postgresql/<version>/main``
-- Launch the restoration from the master
-
-.. code-block:: shell
-
-   sudo -u postgres pg_basebackup -h 10.25.1.1 -D /var/lib/postgresql/16/main/ -P -U replicator --wal-method=fetch
-
-- Restore the :ref:`nominal pacemaker mode <winery-pacemaker-maintenance>`
-
-Postgresql should restart and recover its lag.
-
-- Check the pacemaker after the secondary is up to date
+The PostgreSQL configuration is fully managed inside the patroni configuration,
+either through the main ``/etc/patroni/16-main.yml`` config file for static, host-specific
+configuration, or in patroni's dynamic configuration store