1 files changed, 13 insertions, 3 deletions
diff --git a/routing-generator/src/main/java/com/yahoo/vespa/hosted/routing/nginx/Nginx.java b/routing-generator/src/main/java/com/yahoo/vespa/hosted/routing/nginx/Nginx.java
index b197bff7a51..b6a4cc98038 100644
--- a/routing-generator/src/main/java/com/yahoo/vespa/hosted/routing/nginx/Nginx.java
+++ b/routing-generator/src/main/java/com/yahoo/vespa/hosted/routing/nginx/Nginx.java
@@ -1,4 +1,4 @@
-// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.routing.nginx;
 
 import com.yahoo.collections.Pair;
@@ -48,16 +48,18 @@ public class Nginx implements Router {
     private final Clock clock;
     private final RoutingStatus routingStatus;
     private final Metric metric;
+    private final boolean outputRoutingDiff;
 
     private final Object monitor = new Object();
 
-    public Nginx(FileSystem fileSystem, ProcessExecuter processExecuter, Sleeper sleeper, Clock clock, RoutingStatus routingStatus, Metric metric) {
+    public Nginx(FileSystem fileSystem, ProcessExecuter processExecuter, Sleeper sleeper, Clock clock, RoutingStatus routingStatus, Metric metric, boolean outputRoutingDiff) {
         this.fileSystem = Objects.requireNonNull(fileSystem);
         this.processExecuter = Objects.requireNonNull(processExecuter);
         this.sleeper = Objects.requireNonNull(sleeper);
         this.clock = Objects.requireNonNull(clock);
         this.routingStatus = Objects.requireNonNull(routingStatus);
         this.metric = Objects.requireNonNull(metric);
+        this.outputRoutingDiff = outputRoutingDiff;
     }
 
     @Override
@@ -89,6 +91,7 @@ public class Nginx implements Router {
     private void loadConfig(int upstreamCount) throws IOException {
         Path configPath = NginxPath.config.in(fileSystem);
         Path tempConfigPath = NginxPath.temporaryConfig.in(fileSystem);
+        String routingDiff = "";
         try {
             String currentConfig = Files.readString(configPath);
             String newConfig = Files.readString(tempConfigPath);
@@ -96,6 +99,8 @@ public class Nginx implements Router {
                 Files.deleteIfExists(tempConfigPath);
                 return;
             }
+            if(outputRoutingDiff)
+                routingDiff = " with diff:\n" + getDiff(configPath, tempConfigPath);
             Path rotatedConfig = NginxPath.config.rotatedIn(fileSystem, clock.instant());
             atomicCopy(configPath, rotatedConfig);
         } catch (NoSuchFileException ignored) {
@@ -104,12 +109,17 @@ public class Nginx implements Router {
         Files.move(tempConfigPath, configPath, StandardCopyOption.ATOMIC_MOVE, StandardCopyOption.REPLACE_EXISTING);
         metric.add(CONFIG_RELOADS_METRIC, 1, null);
         // Retry reload. Same rationale for retrying as in testConfig()
-        LOG.info("Loading new configuration file from " + configPath);
+        LOG.info("Loading new configuration file from " + configPath + routingDiff);
         retryingExec("/usr/bin/sudo /opt/vespa/bin/vespa-reload-nginx");
         metric.add(OK_CONFIG_RELOADS_METRIC, 1, null);
         metric.set(GENERATED_UPSTREAMS_METRIC, upstreamCount, null);
     }
 
+    private String getDiff(Path configPath, Path tempConfigPath) throws IOException {
+        Pair<Integer, String> executed = processExecuter.exec("diff -U1 " + configPath + " " + tempConfigPath);
+        return executed.getSecond();
+    }
+
     /** Remove old config files */
     private void gcConfig() throws IOException {
         Instant oneWeekAgo = clock.instant().minus(Duration.ofDays(7));