Added boilerplate for Prometheus

.docker/prometheus/alert.yml

@@ -0,0 +1,6 @@
+groups:
+  - name: DemoAlerts
+    rules:
+      - alert: InstanceDown 
+        expr: up{job="services"} < 1 
+        for: 5m

.docker/prometheus/prometheus.yml

@@ -0,0 +1,17 @@
+global:
+  scrape_interval: 30s
+  scrape_timeout: 10s
+
+rule_files:
+  - alert.yml
+
+scrape_configs:
+  - job_name: services
+    metrics_path: /metrics
+    static_configs:
+      - targets:
+          - 'prometheus:9090'
+  - job_name: 'file_ds'
+    file_sd_configs:
+    - files:
+      - targets.json

.docker/prometheus/targets.json

@@ -0,0 +1,10 @@
+[
+    {
+        "targets": [
+            "api:9091"
+        ],
+        "labels": {
+            "job": "5f11-api"
+        }
+    }
+]