Always generate grafana-config secret

Since https://github.com/brancz/kubernetes-grafana/pull/115, upstream
grafana contains a non-empty config. Generate the grafana-config secret
unconditionally even if no user config is passed.

jsonnet/kube-prometheus/components/grafana.libsonnet

@@ -68,8 +68,7 @@ function(params) {
     },
   },
 
-  // Add object only if user passes config and config is not empty
-  [if std.objectHas(params, 'config') && std.length(params.config) > 0 then 'config']: glib.grafana.config,
+  config: glib.grafana.config,
   service: glib.grafana.service,
   serviceAccount: glib.grafana.serviceAccount,
   deployment: glib.grafana.deployment,

kustomization.yaml

@@ -15,6 +15,7 @@ resources:
 - ./manifests/blackbox-exporter-service.yaml
 - ./manifests/blackbox-exporter-serviceAccount.yaml
 - ./manifests/blackbox-exporter-serviceMonitor.yaml
+- ./manifests/grafana-config.yaml
 - ./manifests/grafana-dashboardDatasources.yaml
 - ./manifests/grafana-dashboardDefinitions.yaml
 - ./manifests/grafana-dashboardSources.yaml

manifests/grafana-config.yaml

@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: Secret
+metadata:
+  labels:
+    app.kubernetes.io/component: grafana
+    app.kubernetes.io/name: grafana
+    app.kubernetes.io/part-of: kube-prometheus
+    app.kubernetes.io/version: 8.1.3
+  name: grafana-config
+  namespace: monitoring
+stringData:
+  grafana.ini: |
+    [date_formats]
+    default_timezone = UTC
+type: Opaque