Merge pull request #71696 from cbippley/OSDOCS-8517-Monitoring

OSDOCS-8517 Monitoring 4.15 RN bugs

Author: JoeAldinger

release_notes/ocp-4-15-release-notes.adoc

@@ -698,27 +698,27 @@ The Network Observability Operator releases updates independently from the {prod
 ==== Hub-side templating for PolicyGenTemplate CRs
 You can manage the configuration of fleets of clusters by using hub templates to populate the group and site values in the generated policies that get applied to managed clusters.
 By using hub templates in group and site `PolicyGenTemplate` (PGT) CRs you can significantly reduce the number of policies on the hub cluster.
-For more information, see xref:../scalability_and_performance/ztp_far_edge/ztp-advanced-policy-config.adoc#ztp-specifying-nics-in-pgt-crs-with-hub-cluster-templates_ztp-advanced-policy-config[Specifying group and site configuration in group PolicyGenTemplate CRs with hub templates]. 
+For more information, see xref:../scalability_and_performance/ztp_far_edge/ztp-advanced-policy-config.adoc#ztp-specifying-nics-in-pgt-crs-with-hub-cluster-templates_ztp-advanced-policy-config[Specifying group and site configuration in group PolicyGenTemplate CRs with hub templates].
 
 [id="ocp-4-15-nto-latency-testing"]
 ==== Node Tuning Operator (NTO)
-The Cloud-native Network Functions (CNF) tests image for latency tests, `cnf-tests`, has been simplified. 
+The Cloud-native Network Functions (CNF) tests image for latency tests, `cnf-tests`, has been simplified.
 The new image has three tests for latency measurements.
-The tests run by default and require a performance profile configured on the cluster. 
-If no performance profile is configured, the tests do not run. 
+The tests run by default and require a performance profile configured on the cluster.
+If no performance profile is configured, the tests do not run.
 
 The following variables are no longer recommended for use:
 
 * `ROLE_WORKER_CNF`
 * `NODES_SELECTOR`
 * `PERF_TEST_PROFILE`
 * `FEATURES`
-* `LATENCY_TEST_RUN` 
-* `DISCOVERY_MODE` 
+* `LATENCY_TEST_RUN`
+* `DISCOVERY_MODE`
 
 To generate the `junit` report, the `--ginkgo.junit-report` flag replaces `--junit`.
 
-For more information, see xref:../scalability_and_performance/cnf-performing-platform-verification-latency-tests.adoc[Performing latency tests for platform verification]. 
+For more information, see xref:../scalability_and_performance/cnf-performing-platform-verification-latency-tests.adoc[Performing latency tests for platform verification].
 
 
 [id="ocp-4-15-hcp"]
@@ -1218,6 +1218,12 @@ See link:https://access.redhat.com/articles/6955985[Navigating Kubernetes API de
 [id="ocp-4-15-monitoring-bug-fixes"]
 ==== Monitoring
 
+* Previously, the monitoring-plugin component did not start if IPv6 was disabled for a cluster. This release updates the component to support the following internet protocol configurations in a cluster: IPv4 only, IPv6 only, and both IPv4 and IPv6 simultaneously. This change resolves the issue, and the monitoring-plugin component now starts up if the cluster is configured to support only IPv6. (link:https://issues.redhat.com/browse/OCPBUGS-21610[*OCPBUGS-21610*])
+
+* Previously, instances of Alertmanager for core platform monitoring and for user-defined projects could inadvertently become peered during an upgrade. This issue could occur when multiple Alertmanager instances were deployed in the same cluster. This release fixes the issue by adding a `--cluster.label` flag to Alertmanager that helps to block any traffic that is not intended for the cluster. (link:https://issues.redhat.com/browse/OCPBUGS-18707[*OCPBUGS-18707*])
+
+* Previously, it was not possible to use text-only email templates in an Alertmanager configuration to send text-only email alerts. With this update, you can configure Alertmanager to send text-only email alerts by setting the `html` field of the email receiver to an empty string. (link:https://issues.redhat.com/browse/OCPBUGS-11713[*OCPBUGS-11713*])
+
 [discrete]
 [id="ocp-4-15-networking-bug-fixes"]
 ==== Networking