From bb073c621bb193e2b92cfd3f94dea18d52f15c12 Mon Sep 17 00:00:00 2001
From: Simon Pasquier <spasquie@redhat.com>
Date: Thu, 25 Jun 2026 16:30:59 +0200
Subject: [PATCH] OCPBUGS-92085: set Prometheus shards value explicitly

As explained in
https://github.com/prometheus-operator/prometheus-operator/issues/6291,
the VPA expects the `.spec.shards` field to be set to an explicit value
to scale the resource.

Signed-off-by: Simon Pasquier <spasquie@redhat.com>
---
 assets/prometheus-k8s/prometheus.yaml                 | 1 +
 assets/prometheus-user-workload/prometheus.yaml       | 1 +
 jsonnet/components/prometheus-user-workload.libsonnet | 2 ++
 jsonnet/components/prometheus.libsonnet               | 2 ++
 4 files changed, 6 insertions(+)

diff --git a/assets/prometheus-k8s/prometheus.yaml b/assets/prometheus-k8s/prometheus.yaml
index a71720aa89..374ddfd457 100644
--- a/assets/prometheus-k8s/prometheus.yaml
+++ b/assets/prometheus-k8s/prometheus.yaml
@@ -231,6 +231,7 @@ spec:
     matchLabels:
       openshift.io/cluster-monitoring: "true"
   serviceMonitorSelector: {}
+  shards: 1
   thanos:
     image: ""
     resources:
diff --git a/assets/prometheus-user-workload/prometheus.yaml b/assets/prometheus-user-workload/prometheus.yaml
index ed6a7138b3..96530e8ecc 100644
--- a/assets/prometheus-user-workload/prometheus.yaml
+++ b/assets/prometheus-user-workload/prometheus.yaml
@@ -298,6 +298,7 @@ spec:
       operator: NotIn
       values:
       - "false"
+  shards: 1
   thanos:
     image: ""
     resources:
diff --git a/jsonnet/components/prometheus-user-workload.libsonnet b/jsonnet/components/prometheus-user-workload.libsonnet
index 66600278eb..46059a7d63 100644
--- a/jsonnet/components/prometheus-user-workload.libsonnet
+++ b/jsonnet/components/prometheus-user-workload.libsonnet
@@ -367,6 +367,8 @@ function(params)
             value: '15ms',
           },
         ],
+        // Explicitly set the shards value to 1 to support VPA use cases.
+        shards: 1,
         containers: [
           {
             name: 'kube-rbac-proxy-federate',
diff --git a/jsonnet/components/prometheus.libsonnet b/jsonnet/components/prometheus.libsonnet
index 16c6c8282c..3a304862d8 100644
--- a/jsonnet/components/prometheus.libsonnet
+++ b/jsonnet/components/prometheus.libsonnet
@@ -403,6 +403,8 @@ function(params)
         // failures when the WAL replay takes a long time.
         // See https://issues.redhat.com/browse/OCPBUGS-4168 for details.
         maximumStartupDurationSeconds: 3600,
+        // Explicitly set the shards value to 1 to support VPA use cases.
+        shards: 1,
         containers: [
           {
             name: 'kube-rbac-proxy-web',