fix: Listen on loopback interface so that k8s port-forward works (#870)

* fix: Listen on loopback interface so that k8s port-forward works

NOTE: This required explicitly listening on eth0, otherwise only the loopback interface would be listening.

* chore: Update changelog

* docs(getting_started): Remove ZooKeeper from example output

* fix: Use unnumbered loopback

* chore: Add comments explaining why we explicitly listen on interfaces

Author: NickLarsenNZ

CHANGELOG.md

@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+### Fixed
+
+- Also listen on the loopback interface so that k8s port-forwards work ([#870]).
+
+[#870]: https://github.com/stackabletech/nifi-operator/pull/870
+
 ## [25.11.0] - 2025-11-07
 
 ## [25.11.0-rc1] - 2025-11-06

docs/modules/nifi/pages/getting_started/first_steps.adoc

@@ -46,7 +46,6 @@ The output should show all pods ready:
 ----
 NAME                                 READY   AGE
 simple-nifi-node-default             2/2     5m
-simple-zk-server-default             3/3     7m
 ----
 
 Congratulations! You successfully created your first NiFi cluster!

rust/operator-binary/src/config/mod.rs

@@ -484,6 +484,20 @@ pub fn build_nifi_properties(
         "nifi.web.https.network.interface.default".to_string(),
         "".to_string(),
     );
+    // Specifically listen on eth0 and lo interfaces.
+    // Listening on lo allows k8s port-forward to work.
+    // Once we listen on lo, we need to explicitly listen on eth0 so the server can be exposed (including health probes).
+    // NOTE: We assume "eth0" is always the external interface in containers launched in Kubernetes.
+    // It is possible that some container runtime will name it differently, but we haven't yet observed that.
+    properties.insert(
+        "nifi.web.https.network.interface.eth0".to_string(),
+        "eth0".to_string(),
+    );
+    properties.insert(
+        "nifi.web.https.network.interface.lo".to_string(),
+        "lo".to_string(),
+    );
+    //#############################################
     properties.insert(
         "nifi.web.jetty.working.directory".to_string(),
         "./work/jetty".to_string(),