From 15ec3aaef6b98fc83f7a405e2cd0f328d5fe6799 Mon Sep 17 00:00:00 2001
From: pober <paul.obernesser@summitwave.eu>
Date: Mon, 18 May 2026 15:26:18 +0200
Subject: [PATCH] removes host file to make mdns working.

---
 src/service/10-link-local-mgmt                | 54 +++----------------
 .../update_and_run_server_and_frontend.sh     |  6 +++
 2 files changed, 13 insertions(+), 47 deletions(-)

diff --git a/src/service/10-link-local-mgmt b/src/service/10-link-local-mgmt
index e4e7b86..324f759 100644
--- a/src/service/10-link-local-mgmt
+++ b/src/service/10-link-local-mgmt
@@ -5,6 +5,8 @@
 # using nmcli device modify (active session only, NOT saved to the profile).
 # The persistent profile always keeps ipv4.link-local=enabled so that
 # direct-connect (no DHCP) plug-ins always activate and trigger events.
+# Avahi is reloaded on each event — no /etc/avahi/hosts file, avahi uses
+# natural per-interface advertisement so each segment gets the right IP.
 #
 # Triggers: up, down, dhcp4-change on ethernet interfaces
 # Install to: /etc/NetworkManager/dispatcher.d/10-link-local-mgmt
@@ -12,56 +14,14 @@
 
 INTERFACE="$1"
 ACTION="$2"
-CONNECTION_NAME="${CONNECTION_ID:-}"
-
 # Only handle ethernet interfaces
 if [[ ! "$INTERFACE" =~ ^eth ]]; then
     exit 0
 fi
 
-# If CONNECTION_ID env var is not set, look up the active connection for this interface
-if [ -z "$CONNECTION_NAME" ]; then
-    CONNECTION_NAME=$(nmcli -t -f NAME,DEVICE connection show --active 2>/dev/null \
-        | grep ":${INTERFACE}$" | cut -d: -f1 | head -n1)
-    [ -z "$CONNECTION_NAME" ] && exit 0
-fi
-
-# Update /etc/avahi/hosts to point mDNS hostname at the best available DHCP address
-# across all ethernet interfaces (so Avahi doesn't advertise a link-local address).
-update_avahi() {
-    local hostname
-    hostname=$(hostname)
-    # Find first non-link-local IPv4 across all ethernet interfaces
-    local dhcp_ip
-    dhcp_ip=$(ip -4 addr show 2>/dev/null \
-        | grep -A5 ': eth' \
-        | grep -oP '(?<=inet\s)\d+(\.\d+){3}' \
-        | grep -v '^127\.' \
-        | grep -v '^169\.254\.' \
-        | head -n1)
-
-    local new_content=""
-    if [ -n "$dhcp_ip" ]; then
-        new_content="$dhcp_ip $hostname $hostname.local"
-    fi
-
-    local current_content
-    current_content=$(cat /etc/avahi/hosts 2>/dev/null || echo "")
-
-    if [ "$new_content" = "$current_content" ]; then
-        logger -t nm-link-local "Avahi: hosts unchanged, skipping reload"
-        return
-    fi
-
-    if [ -n "$dhcp_ip" ]; then
-        mkdir -p /etc/avahi
-        echo "$new_content" > /etc/avahi/hosts
-        logger -t nm-link-local "Avahi: pinned $hostname -> $dhcp_ip"
-    else
-        rm -f /etc/avahi/hosts
-        logger -t nm-link-local "Avahi: removed hosts pin, using all addresses"
-    fi
+reload_avahi() {
     systemctl reload avahi-daemon 2>/dev/null || systemctl restart avahi-daemon 2>/dev/null
+    logger -t nm-link-local "[$INTERFACE] $ACTION — avahi reloaded"
 }
 
 case "$ACTION" in
@@ -73,7 +33,7 @@ case "$ACTION" in
         logger -t nm-link-local "[$INTERFACE] Up — ensuring link-local active (clean slate)"
         (sleep 2 && nmcli device modify "$INTERFACE" ipv4.link-local enabled 2>/dev/null \
             && logger -t nm-link-local "[$INTERFACE] Link-local explicitly enabled on up") &
-        update_avahi
+        reload_avahi
         ;;
 
     dhcp4-change)
@@ -92,13 +52,13 @@ case "$ACTION" in
             (sleep 2 && nmcli device modify "$INTERFACE" ipv4.link-local disabled 2>/dev/null \
                 && logger -t nm-link-local "[$INTERFACE] Link-local suppressed for current session") &
         fi
-        update_avahi
+        reload_avahi
         ;;
 
     down)
         # NOTE: a carrier-change does NOT fully reset session-level 'device modify' state.
         # The re-enable is therefore handled in the 'up' handler when no DHCP is detected.
         logger -t nm-link-local "[$INTERFACE] Down — link-local will be re-enabled on next up without DHCP"
-        update_avahi
+        reload_avahi
         ;;
 esac
diff --git a/src/service/update_and_run_server_and_frontend.sh b/src/service/update_and_run_server_and_frontend.sh
index f3cbe46..57d2e27 100755
--- a/src/service/update_and_run_server_and_frontend.sh
+++ b/src/service/update_and_run_server_and_frontend.sh
@@ -24,6 +24,12 @@ while IFS=: read -r name type; do
 done < <(nmcli -t -f NAME,TYPE connection show)
 
 
+# Remove stale avahi hosts pin — this file overrides per-interface advertisement
+# and causes mDNS to always resolve to eth0's IP regardless of which interface
+# the query arrived on, breaking eth1 mDNS entirely.
+sudo rm -f /etc/avahi/hosts
+sudo systemctl restart avahi-daemon
+
 # Ensure Loopback is loaded with a fixed name and index 
 # Needed for dante
 # TODO image when we create the next image this should be part of it