From ddb504c5c6e023f19224654caf6371ce01b04bbe Mon Sep 17 00:00:00 2001
From: Holger Obermaier <40787752+ho-ob@users.noreply.github.com>
Date: Mon, 2 Mar 2026 15:47:00 +0100
Subject: [PATCH] Fix: Do not overwrite hostname tag if already set (e.g. by
 receivers)

---
 internal/metricRouter/metricRouter.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/internal/metricRouter/metricRouter.go b/internal/metricRouter/metricRouter.go
index 6087387..ea61416 100644
--- a/internal/metricRouter/metricRouter.go
+++ b/internal/metricRouter/metricRouter.go
@@ -180,7 +180,7 @@ func (r *metricRouter) Init(ticker mct.MultiChanTicker, wg *sync.WaitGroup, rout
 	}
 	r.mp.SetNormalizeUnits(r.config.NormalizeUnits)
 
-	err = r.mp.AddAddTagsByCondition("true", r.config.HostnameTagName, r.hostname)
+	err = r.mp.AddAddTagsByCondition("!msg.HasTag('"+r.config.HostnameTagName+"')", r.config.HostnameTagName, r.hostname)
 	if err != nil {
 		return fmt.Errorf("MessageProcessor AddAddTagsByCondition() failed: %w", err)
 	}