[pbs-devel] [PATCH proxmox-backup 1/1] docs: notifications: add section about nested matchers

[Lukas Wagner]

Signed-off-by: Lukas Wagner <l.wagner at proxmox.com>
---
 docs/notifications.rst | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/docs/notifications.rst b/docs/notifications.rst
index 5669dab0..5b990394 100644
--- a/docs/notifications.rst
+++ b/docs/notifications.rst
@@ -258,6 +258,29 @@ Examples:
 The following severities are in use:
 ``info``, ``notice``, ``warning``, ``error``, ``unknown``.
 
+Nested Matcher Rules
+^^^^^^^^^^^^^^^^^^^^
+
+By using ``eval-matcher <other-matcher-name>`` rules, a matcher can evaluate
+other matchers that were marked as a nested matcher. This allows to build
+arbitrarily complex matching rules.
+
+Any matcher that shall be used as a nested matcher must have the ``nested``
+flag set. Nested matchers do not have any associated notification targets. They
+are only evaluated if they are referenced by another matcher's ``eval-matcher``
+rule. If a nested matcher is disabled, it will not be evaluated even if
+referenced by another matcher.
+
+A nested matcher itself can evaluate other nested matchers. Direct (a matcher
+evaluates itself) and indirect (two or more matchers evaluate each other)
+recursion is not allowed.
+
+Examples:
+
+* ``eval-matcher sub-1``: Evaluates the ``sub-1`` matcher and uses its result
+  to compute the result of the current matcher.
+
+
 .. _notification_events:
 
 Notification Events
-- 
2.39.5