Add stub for making alloy the default

Author: alhendrickson

observability/examples/alloy/docker-compose.yml

@@ -50,7 +50,7 @@ services:
       - --server.http.listen-addr=0.0.0.0:12345
       - --storage.path=/var/lib/alloy/data
       - --server.http.ui-path-prefix=/alloy
-      - /etc/alloy/config.alloy
+      - /etc/alloy
     ports:
       - "12345:12345"
     volumes:
@@ -62,11 +62,11 @@ services:
       - /var/lib/docker/:/var/lib/docker:ro
     labels:
       - "traefik.enable=true"
-      - "traefik.http.routers.cadvisor.rule=PathPrefix(`/alloy`)"
+      - "traefik.http.routers.alloy.rule=PathPrefix(`/alloy`)"
     environment:
       - PROMETHEUS_URL=${PROMETHEUS_URL-http://cogstack-observability-prometheus-1:9090/prometheus/api/v1/write}
-      - ALLOY_HOSTNAME=my-custom-host
-      - ALLOY_IP_ADDRESS=my-custom-ip
+      - ALLOY_HOSTNAME=${ALLOY_HOSTNAME} # Used to add a label to metrics
+      - ALLOY_IP_ADDRESS=${ALLOY_IP_ADDRESS} # Used to add a label to metrics
     networks:
       - observability
 networks:

observability/grafana/Dockerfile.alloy

@@ -0,0 +1 @@
+# TODO

observability/grafana/alloy/default-config.alloy

@@ -0,0 +1,38 @@
+logging {
+  level  = "debug"
+  format = "logfmt"
+}
+
+prometheus.remote_write "default" {
+  endpoint {
+    url = sys.env("PROMETHEUS_URL")
+  }
+  external_labels = {
+    host = sys.env("ALLOY_HOSTNAME"),
+    ip_address = sys.env("ALLOY_IP_ADDRESS"),
+  }
+}
+
+prometheus.scrape "exporter" {
+    scrape_interval = "15s"
+    targets    = array.concat(
+        prometheus.exporter.self.alloy.targets,
+        prometheus.exporter.cadvisor.local_cadvisor.targets,
+        prometheus.exporter.unix.local_node_exporter.targets,
+    )
+    forward_to = [prometheus.remote_write.default.receiver]
+}
+
+// Alloys internal metrics
+prometheus.exporter.self "alloy" {
+}
+
+// CAdvisor
+prometheus.exporter.cadvisor "local_cadvisor" {
+  docker_host = "unix:///var/run/docker.sock"
+  storage_duration = "5m"
+}
+
+// Node exporter
+prometheus.exporter.unix "local_node_exporter" {
+}