docs: Update the Prometheus endpoint info

This patch just tidies up some of the links and adds
an example showing how the http_sd_configs option
may be used.

Signed-off-by: Paul Cuzner <pcuzner@redhat.com>
(cherry picked from commit 690d34ab08f22cd988828aa2097531627000907e)

diff --git a/doc/cephadm/services/monitoring.rst b/doc/cephadm/services/monitoring.rst
index 226f0748e0c564565a569ef7a3be1fe962e2af1c..560a95b5146134dc2cbf26fe8844419f545eefa5 100644 (file)
--- a/doc/cephadm/services/monitoring.rst
+++ b/doc/cephadm/services/monitoring.rst
@@ -200,12 +200,12 @@ configuration files for monitoring services.
 Internally, cephadm already uses `Jinja2
 <https://jinja.palletsprojects.com/en/2.11.x/>`_ templates to generate the
 configuration files for all monitoring components. Starting from version 17.2.3,
-cephadm uses Prometheus http service discovery support `http_sd_config
-<https://prometheus.io/docs/prometheus/2.28/configuration/configuration/#http_sd_config>`
-in order to get the currently configured targets from Ceph. Internally, `ceph-mgr`
-provides a service discovery endpoint at `<https://<mgr-ip>:8765/sd/` (port is
-configurable through the variable `service_discovery_port`) which is used by
-Prometheus to get the needed targets.
+cephadm supports Prometheus http service discovery, and uses this endpoint for the
+definition and management of the embedded Prometheus service. The endpoint listens on
+``https://<mgr-ip>:8765/sd/`` (the port is
+configurable through the variable ``service_discovery_port``) and returns scrape target
+information in `http_sd_config format
+<https://prometheus.io/docs/prometheus/latest/configuration/configuration/#http_sd_config/>`_
 
 Customers with external monitoring stack can use `ceph-mgr` service discovery endpoint
 to get scraping configuration. Root certificate of the server can be obtained by the
@@ -312,11 +312,20 @@ cluster.
   By default, ceph-mgr presents prometheus metrics on port 9283 on each host
   running a ceph-mgr daemon.  Configure prometheus to scrape these.
 
-To make this integration easier, Ceph provides by means of `ceph-mgr` a service
-discovery endpoint at `<https://<mgr-ip>:8765/sd/` which can be used by an external
-Prometheus to retrieve targets information. Information reported by this EP used
-the format specified by `http_sd_config
-<https://prometheus.io/docs/prometheus/2.28/configuration/configuration/#http_sd_config>`
+To make this integration easier, cephadm provides a service discovery endpoint at
+``https://<mgr-ip>:8765/sd/``. This endpoint can be used by an external
+Prometheus server to retrieve target information for a specific service. Information returned
+by this endpoint uses the format specified by the Prometheus `http_sd_config option
+<https://prometheus.io/docs/prometheus/latest/configuration/configuration/#http_sd_config/>`_
+
+Here's an example prometheus job definition that uses the cephadm service discovery endpoint
+
+  .. code-block:: bash
+
+     - job_name: 'ceph-exporter'  
+       http_sd_configs:  
+       - url: http://<mgr-ip>:8765/sd/prometheus/sd-config?service=ceph-exporter
+
 
 * To enable the dashboard's prometheus-based alerting, see :ref:`dashboard-alerting`.