OP#662 add flags to harden the alloy for better tracking

templates/config.alloy.erb

@@ -79,9 +79,15 @@ prometheus.scrape "node_exporter" {
   targets                     = discovery.relabel.node_exporter.output
   forward_to                  = [prometheus.remote_write.prometheus.receiver]
   scrape_interval             = "15s"
+  honor_timestamps            = true
+  track_timestamps_staleness  = true
 }
 
 prometheus.remote_write "prometheus" {
+  external_labels = {
+    // makes every series from this Alloy unmistakably unique
+    alloy_instance = constants.hostname,
+  }
   endpoint {
     url = "<%= @ay_prom_url %>"
     basic_auth {