Merge pull request #58255 from jbgi/prometheus2

Add Prometheus 2 service in parallel with 1.x version (continuation)

1 files changed, 46 insertions, 1 deletions

diff --git a/nixos/doc/manual/release-notes/rl-1909.xml b/nixos/doc/manual/release-notes/rl-1909.xml
index 2cfaec49c02e..2d391b750537 100644
--- a/nixos/doc/manual/release-notes/rl-1909.xml
+++ b/nixos/doc/manual/release-notes/rl-1909.xml
@@ -37,7 +37,52 @@
 
   <itemizedlist>
    <listitem>
-    <para />
+    <para>
+       Besides the existing <option>services.prometheus</option> module which
+       targets Prometheus-1 a new <option>services.prometheus2</option> module
+       has been added which targets Prometheus-2.
+    </para>
+    <para>
+       Both modules can be enabled at the same time. In fact
+       <link xlink:href="https://prometheus.io/docs/prometheus/latest/migration/#storage">
+       this is needed for upgrading existing Prometheus-1 data to Prometheus-2
+       </link>.
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+
+ <section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         version="5.0"
+         xml:id="sec-release-19.09-incompatibilities">
+  <title>Backward Incompatibilities</title>
+
+  <para>
+   When upgrading from a previous release, please be aware of the following
+   incompatible changes:
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+      The directory where Prometheus will store its metric data is now
+      managed by systemd's StateDirectory mechanism. It still defaults
+      to <literal>/var/lib/prometheus</literal>.
+    </para>
+    <para>
+      Its location can be specified by the new
+      <option>services.prometheus.stateDir</option> option which
+      defaults to <literal>prometheus</literal>. Note that this should
+      be a directory relative to <literal>/var/lib/</literal>.
+    </para>
+    <para>
+      The option <option>services.prometheus.dataDir</option> has been
+      deprecated. You can still set it but it's now required to have
+      <literal>/var/lib/</literal> as a prefix and you can't set
+      <option>services.prometheus.stateDir</option> at the same time.
+    </para>
    </listitem>
   </itemizedlist>
  </section>