From c8080ca0e04e4b3cb4f914ffda7fa79522843c23 Mon Sep 17 00:00:00 2001
From: Justin Karneges <jkarneges@fastly.com>
Date: Mon, 14 Sep 2026 10:54:28 -0700
Subject: [PATCH] allow prometheus prefixes to override component names

---
 src/bin/pushpin-connmgr.rs |  2 +-
 src/connmgr/mod.rs         | 10 ++++++----
 src/proxy/proxyapp.cpp     |  2 +-
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/bin/pushpin-connmgr.rs b/src/bin/pushpin-connmgr.rs
index e3154de4b..25519b499 100644
--- a/src/bin/pushpin-connmgr.rs
+++ b/src/bin/pushpin-connmgr.rs
@@ -197,7 +197,7 @@ fn process_args_and_run(args: Args) -> Result<(), Box<dyn Error>> {
             NetListenConfig::Unix(c) => &mut c.params,
         };
 
-        let prefix = params.remove("prefix").unwrap_or_default();
+        let prefix = params.remove("prefix").unwrap_or("connmgr".to_string());
 
         if let Some(k) = params.keys().next() {
             return Err(format!("failed to parse prometheus: invalid param: {}", k).into());
diff --git a/src/connmgr/mod.rs b/src/connmgr/mod.rs
index 600a33e83..c36dae258 100644
--- a/src/connmgr/mod.rs
+++ b/src/connmgr/mod.rs
@@ -165,10 +165,12 @@ impl App {
         let mut prometheus = None;
 
         if let Some(config) = &config.prometheus {
-            let combined_prefix = format!("{}connmgr", config.prefix);
-
-            let registry = prometheus::Registry::new_custom(Some(combined_prefix), None)
-                .expect("failed to create prometheus registry");
+            let trimmed = config.prefix.trim_end_matches('_');
+            let registry = prometheus::Registry::new_custom(
+                (!trimmed.is_empty()).then(|| trimmed.to_string()),
+                None,
+            )
+            .expect("failed to create prometheus registry");
 
             try_register_process_collector(&registry)
                 .expect("failed to register process collector");
diff --git a/src/proxy/proxyapp.cpp b/src/proxy/proxyapp.cpp
index 26700cd19..855b102f0 100644
--- a/src/proxy/proxyapp.cpp
+++ b/src/proxy/proxyapp.cpp
@@ -471,7 +471,7 @@ int proxy_init(const ffi::ProxyCliArgs *argsFfi) {
     int statsConnectionsMaxTtl = settings.value("proxy/stats_connections_max_ttl", 60).toInt();
     int statsReportInterval = settings.value("proxy/stats_report_interval", 10).toInt();
     QString prometheusPort = settings.value("proxy/prometheus_port").toString();
-    QString prometheusPrefix = settings.value("proxy/prometheus_prefix").toString();
+    QString prometheusPrefix = settings.value("proxy/prometheus_prefix", "proxy").toString();
 
     QList<QByteArray> origHeadersNeedMark;
     foreach (const QString &s, origHeadersNeedMarkStr)