From 3919865c65446d1bd3cf0b3a7d74f529d0984b15 Mon Sep 17 00:00:00 2001
From: Shubhankar Ranade <sranade@confluent.io>
Date: Wed, 2 Apr 2025 20:23:36 +0530
Subject: [PATCH 1/2] Upgrade log4j1 to log4j2

---
 NOTICE                                        |  6 ++++++
 kafka-rest/pom.xml                            | 15 ++++++++++++--
 kafka-rest/src/assembly/package.xml           |  4 ++--
 licenses/NOTICE.confluent-common.txt          |  6 ++++++
 licenses/NOTICE.confluent-schema-registry.txt |  6 ++++++
 licenses/NOTICE.log4j2.txt                    | 20 +++++++++++++++++++
 6 files changed, 53 insertions(+), 4 deletions(-)
 create mode 100644 licenses/NOTICE.log4j2.txt

diff --git a/NOTICE b/NOTICE
index 3272f57829..16dd1ec732 100644
--- a/NOTICE
+++ b/NOTICE
@@ -24,6 +24,12 @@ The following libraries are included in packaged versions of this project:
  * NOTICE: licenses/NOTICE.log4j.txt
  * HOMEPAGE: http://logging.apache.org/log4j/1.2/
 
+* Apache Log4j
+ * COPYRIGHT: Copyright 1999-2024 Apache Software Foundation
+ * LICENSE: licenses/LICENSE.apache2.txt
+ * NOTICE: licenses/NOTICE.log4j2.txt
+ * HOMEPAGE: https://logging.apache.org/log4j/2.x/
+
 * Apache ZooKeeper
  * COPYRIGHT: Copyright 2009-2014 The Apache Software Foundation
  * LICENSE: licenses/LICENSE.apache2.txt
diff --git a/kafka-rest/pom.xml b/kafka-rest/pom.xml
index baa53211e4..8456c853bb 100644
--- a/kafka-rest/pom.xml
+++ b/kafka-rest/pom.xml
@@ -63,8 +63,13 @@
             <version>${io.confluent.schema-registry.version}</version>
         </dependency>
         <dependency>
-            <groupId>org.slf4j</groupId>
-            <artifactId>slf4j-reload4j</artifactId>
+            <groupId>org.apache.logging.log4j</groupId>
+            <artifactId>log4j-slf4j-impl</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-yaml</artifactId>
+            <scope>runtime</scope>
         </dependency>
         <dependency>
             <groupId>io.confluent</groupId>
@@ -147,6 +152,12 @@
             <artifactId>kafka-schema-registry</artifactId>
             <version>${io.confluent.schema-registry.version}</version>
             <scope>test</scope>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.slf4j</groupId>
+                    <artifactId>slf4j-reload4j</artifactId>
+                </exclusion>
+            </exclusions>
         </dependency>
         <dependency>
             <groupId>org.easymock</groupId>
diff --git a/kafka-rest/src/assembly/package.xml b/kafka-rest/src/assembly/package.xml
index 1a61dd2bf2..768a34db46 100644
--- a/kafka-rest/src/assembly/package.xml
+++ b/kafka-rest/src/assembly/package.xml
@@ -47,7 +47,7 @@
             <excludes>
                 <exclude>io.confluent:rest-utils</exclude>
                 <exclude>org.slf4j:slf4j-log4j12</exclude>
-                <exclude>org.slf4j:slf4j-reload4j</exclude>
+                <exclude>org.apache.logging.log4j:log4j-slf4j-impl</exclude>
             </excludes>
         </dependencySet>
         <dependencySet>
@@ -55,7 +55,7 @@
             <useProjectArtifact>false</useProjectArtifact>
             <useTransitiveFiltering>true</useTransitiveFiltering>
             <includes>
-                <include>org.slf4j:slf4j-reload4j</include>
+                <include>org.apache.logging.log4j:log4j-slf4j-impl</include>
             </includes>
         </dependencySet>
     </dependencySets>
diff --git a/licenses/NOTICE.confluent-common.txt b/licenses/NOTICE.confluent-common.txt
index b92ef9032d..8ec0261f03 100644
--- a/licenses/NOTICE.confluent-common.txt
+++ b/licenses/NOTICE.confluent-common.txt
@@ -6,6 +6,12 @@ The following libraries are included in packaged versions of this project:
  * NOTICE: licenses/NOTICE.log4j.txt
  * HOMEPAGE: http://logging.apache.org/log4j/1.2/
 
+* Apache Log4j
+ * COPYRIGHT: Copyright 1999-2024 Apache Software Foundation
+ * LICENSE: licenses/LICENSE.apache2.txt
+ * NOTICE: licenses/NOTICE.log4j2.txt
+ * HOMEPAGE: https://logging.apache.org/log4j/2.x/
+
 * Apache ZooKeeper
  * COPYRIGHT: Copyright 2009-2014 The Apache Software Foundation
  * LICENSE: licenses/LICENSE.apache2.txt
diff --git a/licenses/NOTICE.confluent-schema-registry.txt b/licenses/NOTICE.confluent-schema-registry.txt
index c4b34db389..95277c0d54 100644
--- a/licenses/NOTICE.confluent-schema-registry.txt
+++ b/licenses/NOTICE.confluent-schema-registry.txt
@@ -24,6 +24,12 @@ The following libraries are included in packaged versions of this project:
  * NOTICE: licenses/NOTICE.log4j.txt
  * HOMEPAGE: http://logging.apache.org/log4j/1.2/
 
+* Apache Log4j
+ * COPYRIGHT: Copyright 1999-2024 Apache Software Foundation
+ * LICENSE: licenses/LICENSE.apache2.txt
+ * NOTICE: licenses/NOTICE.log4j2.txt
+ * HOMEPAGE: https://logging.apache.org/log4j/2.x/
+
 * Apache ZooKeeper
  * COPYRIGHT: Copyright 2009-2014 The Apache Software Foundation
  * LICENSE: licenses/LICENSE.apache2.txt
diff --git a/licenses/NOTICE.log4j2.txt b/licenses/NOTICE.log4j2.txt
new file mode 100644
index 0000000000..0c37b52bfe
--- /dev/null
+++ b/licenses/NOTICE.log4j2.txt
@@ -0,0 +1,20 @@
+Apache Log4j
+Copyright 1999-2024 Apache Software Foundation
+
+This product includes software developed at
+The Apache Software Foundation (http://www.apache.org/).
+
+ResolverUtil.java
+Copyright 2005-2006 Tim Fennell
+
+Dumbster SMTP test server
+Copyright 2004 Jason Paul Kitchen
+
+TypeUtil.java
+Copyright 2002-2012 Ramnivas Laddad, Juergen Hoeller, Chris Beams
+
+picocli (http://picocli.info)
+Copyright 2017 Remko Popma
+
+TimeoutBlockingWaitStrategy.java and parts of Util.java
+Copyright 2011 LMAX Ltd.

From 65e95460a95f0341b4f07018a3c81bbb488ce818 Mon Sep 17 00:00:00 2001
From: Shubhankar Ranade <sranade@confluent.io>
Date: Thu, 3 Apr 2025 13:25:28 +0530
Subject: [PATCH 2/2] Migrate properties files to yaml

---
 config/log4j.properties                       | 12 -------
 config/log4j2.yaml                            | 32 +++++++++++++++++++
 .../src/test/resources/log4j.properties       | 15 ---------
 kafka-rest/src/test/resources/log4j2.yaml     | 22 +++++++++++++
 4 files changed, 54 insertions(+), 27 deletions(-)
 delete mode 100644 config/log4j.properties
 create mode 100644 config/log4j2.yaml
 delete mode 100644 kafka-rest/src/test/resources/log4j.properties
 create mode 100644 kafka-rest/src/test/resources/log4j2.yaml

diff --git a/config/log4j.properties b/config/log4j.properties
deleted file mode 100644
index ff3a93fb2a..0000000000
--- a/config/log4j.properties
+++ /dev/null
@@ -1,12 +0,0 @@
-log4j.rootLogger=INFO, stdout, file
-
-log4j.appender.stdout=org.apache.log4j.ConsoleAppender
-log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
-log4j.appender.stdout.layout.ConversionPattern=[%d] %p %m (%c:%L)%n
-
-log4j.appender.file=org.apache.log4j.RollingFileAppender
-log4j.appender.file.maxBackupIndex=10
-log4j.appender.file.maxFileSize=100MB
-log4j.appender.file.File=${kafka-rest.log.dir}/kafka-rest.log
-log4j.appender.file.layout=org.apache.log4j.PatternLayout
-log4j.appender.file.layout.ConversionPattern=[%d] %p %m (%c)%n
diff --git a/config/log4j2.yaml b/config/log4j2.yaml
new file mode 100644
index 0000000000..82c2e341f4
--- /dev/null
+++ b/config/log4j2.yaml
@@ -0,0 +1,32 @@
+Configuration:
+  name: "Log4j2"
+  Properties:
+    Property:
+      # Fallback if the system property is not set
+      - name: "kafka-rest.logs.dir"
+        value: "."
+  Appenders:
+    RollingFile:
+      name: "file"
+      fileName: "${sys:kafka-rest.log.dir}/kafka-rest.log"
+      filePattern: "/kafka-rest.log.%i"
+      PatternLayout:
+        pattern: "[%d] %v1Level %m (%c)%n"
+      Policies:
+        SizeBasedTriggeringPolicy:
+          size: "100MB"
+      DefaultRolloverStrategy:
+        max: "10"
+        # Using the min strategy, the newest log file will have index 1 and the oldest one will have index max.
+        fileIndex: "min"
+    Console:
+      name: "STDOUT"
+      target: "SYSTEM_OUT"
+      PatternLayout:
+        pattern: "[%d] %v1Level %m (%c:%L)%n"
+  Loggers:
+    Root:
+      level: "INFO"
+      AppenderRef:
+        - ref: "file"
+        - ref: "STDOUT"
diff --git a/kafka-rest/src/test/resources/log4j.properties b/kafka-rest/src/test/resources/log4j.properties
deleted file mode 100644
index 613a431401..0000000000
--- a/kafka-rest/src/test/resources/log4j.properties
+++ /dev/null
@@ -1,15 +0,0 @@
-log4j.rootLogger=TRACE, stdout
-
-log4j.appender.stdout=org.apache.log4j.ConsoleAppender
-log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
-log4j.appender.stdout.layout.ConversionPattern=[%d] %p %m (%c:%L)%n
-
-log4j.logger.kafka=ERROR
-log4j.logger.org.apache.kafka=ERROR
-
-# zkclient can be verbose, during debugging it is common to adjust is separately
-log4j.logger.org.I0Itec.zkclient=ERROR
-log4j.logger.org.apache.zookeeper=ERROR
-
-log4j.logger.org.eclipse=ERROR
-log4j.logger.org.hibernate.validator=ERROR
\ No newline at end of file
diff --git a/kafka-rest/src/test/resources/log4j2.yaml b/kafka-rest/src/test/resources/log4j2.yaml
new file mode 100644
index 0000000000..4fc0df1b18
--- /dev/null
+++ b/kafka-rest/src/test/resources/log4j2.yaml
@@ -0,0 +1,22 @@
+Configuration:
+  name: "Log4j2"
+  Appenders:
+    Console:
+      name: "STDOUT"
+      target: "SYSTEM_OUT"
+      PatternLayout:
+        pattern: "[%d] %v1Level %m (%c:%L)%n"
+  Loggers:
+    Root:
+      level: "TRACE"
+      AppenderRef:
+        ref: "STDOUT"
+    Logger:
+      - name: "kafka"
+        level: "ERROR"
+      - name: "org.apache.kafka"
+        level: "ERROR"
+      - name: "org.eclipse"
+        level: "ERROR"
+      - name: "org.hibernate.validator"
+        level: "ERROR"