documentation updates and remove unused references to variables

CHANGES.md

@@ -27,9 +27,6 @@
   added by default see the 
   ``optional-components/prometheus-longterm-metrics/config/monitoring/prometheus.rules.template`` file.
 
-  If you do not want the default longterm-metric rules included, set the ``PROMETHEUS_LONGTERM_RULES_FILE`` to anything 
-  other than ``True`` in your ``env.local`` file.
-
   To configure this component:
 
   * update the ``PROMETHEUS_LONGTERM_RETENTION_TIME`` variable to set how long the data will be kept by prometheus
@@ -44,13 +41,13 @@
   by updating the ``env.local`` file. These set the login credentials for the root user that runs the 
   [minio](https://min.io/) object store.
 
-  Enabling the `thanos` component creates the additional endpoints:
+- Enabling the `thanos` component creates the additional endpoints:
 
   * ``/thanos-query``: a prometheus-like query interface to inspect the data stored by thanos
   * ``/thanos-minio``: a minio web console to inspect the data stored by minio.
 
-  This also includes an update to the prometheus version from `v2.19.0` to the current latest `v2.52.0`. This is to
-  required to support the interaction between prometheus and thanos.
+- Update the prometheus version from `v2.19.0` to the current latest `v2.52.0`. This is required to support the interaction between 
+  prometheus and thanos.
 
 [2.5.3](https://github.com/bird-house/birdhouse-deploy/tree/2.5.3) (2024-09-11)
 ------------------------------------------------------------------------------------------------------------------

birdhouse/components/README.rst

@@ -371,6 +371,7 @@ AlertManager for Alert Dashboard and Silencing
 .. image:: monitoring/images/alertmanager-dashboard.png
 .. image:: monitoring/images/alertmanager-silence-alert.png
 
+.. _monitoring-customize-the-component
 
 Customizing the Component
 -------------------------
@@ -389,6 +390,23 @@ Customizing the Component
   Slack or other services accepting webhooks), ``ALERTMANAGER_EXTRA_RECEIVERS``.
 
 
+Longterm Storage of Prometheus Metrics
+--------------------------------------
+
+Prometheus stores metrics for 90 days by default. This may be sufficient for some use cases but you may wish to store
+some metrics for longer. In order to store certain metrics for a longer than 90 days, you can enable the following
+additional components:
+
+- :ref:`prometheus-longterm-metrics`: a second Prometheus instance used to collect the metrics that you want to store longterm
+- :ref:`thanos`: a service that enables more efficient storage of the metrics collected by the :ref:`prometheus-longterm-metrics`
+  component.
+
+.. note::
+    A separate prometheus instance is necessary since the retention time for prometheus metrics is set at the 
+    instance level. This means that increasing the retention time must be done for all metrics at once which is undesirable
+    because you probably don't need to store every metric for a long period of time and you'll end up using a lot more
+    disk space than needed.
+
 Weaver
 ======
 

birdhouse/optional-components/README.rst

@@ -444,6 +444,8 @@ How to enable X-Robots-Tag Header in ``env.local`` (a copy from `env.local.examp
     .. seealso::
         See the `env.local.example`_ file for more details about this ``BIRDHOUSE_PROXY_ROOT_LOCATION`` behaviour.
 
+.. _prometheus-longterm-metrics
+
 Prometheus Long-term Metrics
 ----------------------------
 
@@ -454,15 +456,17 @@ Longterm metrics are any prometheus rule that have the label ``group: longterm-m
 selectable using prometheus' ``'{group="longterm-metrics"}'`` query filter. To add some default longterm metrics rules
 also enable the ``prometheus-longterm-rules`` component.
 
-You may also choose to create your own set of rules in another component that you would like to use instead of the
-default ones.
+You may also choose to create your own set of rules instead of, or as well as, the default ones. See how to 
+:ref:`add additional rules here <monitoring-customize-the-component>`.
 
 To configure this component:
 
     * update the ``PROMETHEUS_LONGTERM_RETENTION_TIME`` variable to set how long the data will be kept by prometheus
 
 Enabling this component creates the additional endpoint ``/prometheus-longterm-metrics``.
 
+.. _prometheus-longterm-rules
+
 Prometheus Long-term Rules
 --------------------------
 
@@ -472,6 +476,8 @@ component. These rules all have the label ``group: longterm-metrics``.
 To see which rules are added, check out the
 `optional-components/prometheus-longterm-rules/config/monitoring/prometheus.rules` file.
 
+.. _thanos
+
 Thanos
 ------
 

birdhouse/optional-components/prometheus-longterm-metrics/default.env

@@ -23,7 +23,6 @@ export DELAYED_EVAL="
   PROMETHEUS_LONGTERM_VERSION
   PROMETHEUS_LONGTERM_DOCKER
   PROMETHEUS_LONGTERM_IMAGE
-  PROMETHEUS_LONGTERM_RULES_FILE
 "
 
 # Note that this component does not depend explicitly on the `components/monitoring` component so that this can