Merge pull request #2759 from jan--f/thanos-ruler-retention-default

MON-4444: thanos-ruler: set default retention from UWM Prometheus if present

Author: openshift-merge-bot[bot]

pkg/manifests/config.go

@@ -664,6 +664,13 @@ func (u *UserWorkloadConfiguration) applyDefaults() {
 	if u.ThanosRuler == nil {
 		u.ThanosRuler = &ThanosRulerConfig{}
 	}
+	// If the user configured a retention for user-workload Prometheus but did not
+	// explicitly set a retention for Thanos Ruler, default Thanos Ruler retention
+	// to the same value as Prometheus. This keeps the effective retention aligned
+	// unless the user overrides it for Thanos Ruler.
+	if u.ThanosRuler.Retention == "" && u.Prometheus != nil && u.Prometheus.Retention != "" {
+		u.ThanosRuler.Retention = u.Prometheus.Retention
+	}
 	if u.Alertmanager == nil {
 		u.Alertmanager = &AlertmanagerUserWorkloadConfig{}
 	}

pkg/manifests/config_test.go

@@ -261,6 +261,34 @@ thanosRuler:
 				return ``
 			},
 		},
+		{
+			name: "thanosRuler.retention defaults to prometheus.retention when unset",
+			configString: func() string {
+				return `
+prometheus:
+  retention: 15d
+`
+			},
+			configCheck: func(uwmc *UserWorkloadConfiguration) {
+				require.Equal(t, "15d", uwmc.Prometheus.Retention)
+				require.Equal(t, "15d", uwmc.ThanosRuler.Retention)
+			},
+		},
+		{
+			name: "explicit thanosRuler.retention overrides prometheus.retention",
+			configString: func() string {
+				return `
+prometheus:
+  retention: 15d
+thanosRuler:
+  retention: 7d
+`
+			},
+			configCheck: func(uwmc *UserWorkloadConfiguration) {
+				require.Equal(t, "15d", uwmc.Prometheus.Retention)
+				require.Equal(t, "7d", uwmc.ThanosRuler.Retention)
+			},
+		},
 	}
 
 	for _, tc := range tcs {

pkg/manifests/manifests_test.go

@@ -4305,6 +4305,36 @@ func TestThanosRulerRetentionConfig(t *testing.T) {
 	}
 }
 
+func TestThanosRulerRetentionDefaultsToPrometheusRetention(t *testing.T) {
+	// Construct a user-workload configuration the same way the operator does in
+	// production, i.e. via NewUserConfigFromString, so that UserWorkloadConfiguration
+	// defaulting (including retention alignment) is applied.
+	uwc, err := NewUserConfigFromString(`
+prometheus:
+  retention: 45d
+`)
+	require.NoError(t, err)
+
+	c := NewDefaultConfig()
+	c.UserWorkloadConfiguration = uwc
+
+	f := NewFactory("openshift-monitoring", "openshift-user-workload-monitoring", c, defaultInfrastructureReader(), &fakeProxyReader{}, NewAssets(assetsPath), &APIServerConfig{}, &configv1.Console{})
+
+	tr, err := f.ThanosRulerCustomResource(
+		&v1.Secret{ObjectMeta: metav1.ObjectMeta{Name: "foo"}},
+		nil,
+	)
+
+	if err != nil {
+		t.Fatalf("Unexpected error occured %v", err)
+		return
+	}
+
+	if tr.Spec.Retention != "45d" {
+		t.Fatalf("Retention is not configured correctly, expected %s, got %s", "45d", tr.Spec.Retention)
+	}
+}
+
 func TestPrometheusGoGCRelatedConfig(t *testing.T) {
 	for _, tc := range []struct {
 		ir    InfrastructureReader