fix: prometheus network policy let prometheus-adapter pass (#1982)

jsonnet/kube-prometheus/components/prometheus.libsonnet

@@ -116,6 +116,18 @@ function(params) {
           port: o.port,
           protocol: 'TCP',
         }, p.service.spec.ports),
+      }, {
+        from: [{
+          podSelector: {
+            matchLabels: {
+              'app.kubernetes.io/name': 'prometheus-adapter',
+            },
+          },
+        }],
+        ports: [{
+          port: 9090,
+          protocol: 'TCP',
+        }],
       }, {
         from: [{
           podSelector: {

manifests/prometheus-networkPolicy.yaml

@@ -22,6 +22,13 @@ spec:
       protocol: TCP
     - port: 8080
       protocol: TCP
+  - from:
+    - podSelector:
+        matchLabels:
+          app.kubernetes.io/name: prometheus-adapter
+    ports:
+    - port: 9090
+      protocol: TCP
   - from:
     - podSelector:
         matchLabels: