Add observer, prometheus and grafana

docker/prometheus/prometheus.yml

@@ -0,0 +1,22 @@
+global:
+  scrape_interval: 5s
+
+scrape_configs:
+  - job_name: 'eventhub-node1'
+    static_configs:
+      - targets: ['eventhub-node1:8080'] # http://localhost:8080/metrics/default
+        labels:
+          node: 'node1'
+    metrics_path: '/metrics/default'
+  - job_name: 'eventhub-node2'
+    static_configs:
+      - targets: ['eventhub-node2:8080']
+        labels:
+          node: 'node2'
+    metrics_path: '/metrics/default'
+  - job_name: 'eventhub-node3'
+    static_configs:
+      - targets: ['eventhub-node3:8080']
+        labels:
+          node: 'node3'
+    metrics_path: '/metrics/default'