DEV: Support env var for prometheus port in cache_critical_dns

DEV: Support env var for prometheus port in cache_critical_dns

diff --git a/script/cache_critical_dns b/script/cache_critical_dns
index 5b75ddc..0b1ecbe 100755
--- a/script/cache_critical_dns
+++ b/script/cache_critical_dns
@@ -58,7 +58,7 @@ end
 
 def send_counter(name, description, labels, value)
   host = "localhost"
-  port = 9405
+  port = ENV.fetch("DISCOURSE_PROMETHEUS_COLLECTOR_PORT", 9405).to_i
 
   if labels
     labels = labels.map do |k, v|

GitHub sha: 53005891