From 4be5fe7c461d2287a95b6db415a1f97d3ed48502 Mon Sep 17 00:00:00 2001
From: Kyle Lemons <kyle.lemons@reddit.com>
Date: Fri, 4 Nov 2022 13:12:52 -0700
Subject: [PATCH] Make reregistration of prom metrics resilient to v0 + v2

---
 internal/admin/server.go | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/internal/admin/server.go b/internal/admin/server.go
index 5ee5ebdfa..6d4397ca7 100644
--- a/internal/admin/server.go
+++ b/internal/admin/server.go
@@ -35,11 +35,11 @@ func init() {
 
 	Mux.Handle("/metrics", promhttp.Handler())
 
-	// Unregister the default GoCollector.
-	prometheus.Unregister(collectors.NewGoCollector())
-
-	// Register GoCollector with baseplate defaults.
-	prometheus.MustRegister(collectors.NewGoCollector(baseplateGoCollectors))
+	// Unregister the default GoCollector, and reregister with baseplate defaults
+	if prometheus.Unregister(collectors.NewGoCollector()) {
+		// Only register a new collector if we unregistered one to avoid double-reregistration
+		prometheus.MustRegister(collectors.NewGoCollector(baseplateGoCollectors))
+	}
 }
 
 func Serve() error {