Update Strimzi to Java 21 (#12291)

Signed-off-by: Jakub Scholz <www@scholzj.com>

Author: scholzj

.azure/templates/jobs/build/build_strimzi.yaml

@@ -4,8 +4,8 @@ jobs:
     # Strategy for the job
     strategy:
       matrix:
-        'build_strimzi_java-17':
-          jdk_version: '17'
+        'build_strimzi_java-21':
+          jdk_version: '21'
           main_build: 'true'
     # Set timeout for jobs
     timeoutInMinutes: 60

.azure/templates/jobs/build/deploy_strimzi_java.yaml

@@ -4,8 +4,8 @@ jobs:
     # Strategy for the job
     strategy:
       matrix:
-        'deploy_strimzi_java-17':
-          jdk_version: '17'
+        'deploy_strimzi_java-21':
+          jdk_version: '21'
           main_build: 'true'
     # Set timeout for jobs
     timeoutInMinutes: 60

.azure/templates/jobs/build/test_strimzi.yaml

@@ -4,8 +4,8 @@ jobs:
     # Strategy for the job
     strategy:
       matrix:
-        'test_strimzi_java-17':
-          jdk_version: '17'
+        'test_strimzi_java-21':
+          jdk_version: '21'
           main_build: 'true'
     # Set timeout for jobs
     timeoutInMinutes: 90

.azure/templates/steps/prerequisites/install_java.yaml

@@ -1,7 +1,7 @@
 # Step to configure JAVA on the agent
 parameters:
   - name: JDK_VERSION
-    default: '17'
+    default: '21'
 steps:
   - task: JavaToolInstaller@0
     inputs:

.azure/templates/steps/system_test_general.yaml

@@ -22,7 +22,7 @@ jobs:
   strategy:
     matrix:
       ${{ parameters.name }}:
-        jdk_version: '17'
+        jdk_version: '21'
   # Base system
   pool:
     vmImage: 'Ubuntu-22.04'

.github/actions/dependencies/setup-java/action.yml

@@ -9,7 +9,7 @@ inputs:
   javaVersion:
     description: "Java version to be installed"
     required: false
-    default: "17"
+    default: "21"
   javaDistro:
     description: "Java distribution to be installed"
     required: false

.github/workflows/codeql-analysis.yml

@@ -48,7 +48,7 @@ jobs:
     - name: Install yq
       uses: ./.github/actions/dependencies/install-yq
 
-    # Setup OpenJDK 17
+    # Setup OpenJDK 21
     - name: Setup Java and Maven
       uses: ./.github/actions/dependencies/setup-java
 

CHANGELOG.md

@@ -2,10 +2,15 @@
 
 ## 0.50.0
 
-* Nothing here yet, but we will surely develop something new pretty soon 😉
+* Use Java 21 as the runtime and language level
 
 ### Major changes, deprecations, and removals
 
+* Strimzi Operators are now using Java 21 as the runtime and language level.
+  The only exceptions are the `api`, `test`, `crd-annotations`, and `crd-generator` modules which use Java 11 as the language level for compatibility with older java versions.
+  These modules will remain using the Java 11 language level up to and including Strimzi 0.51.
+  They will move to Java 21 language level in Strimzi 1.0.0.
+  If you use one of these modules as a dependency in your Java project, you will need to upgrade to Java 21 as well. 
 * `connector.plugin.version` option is now forbidden in `KafkaConnect` CR in `.spec.config` and in `KafkaMirrorMaker2` CR in `.spec.mirrors[].sourceConnector.config` and `.spec.mirrors[].checkpointConnector.config`. Please use the dedicated `version` field instead.
 
 ## 0.49.1

development-docs/DEV_GUIDE.md

@@ -66,17 +66,17 @@ run `brew install bash` to install a compatible version of `bash`. If you wish t
 updated bash run `sudo bash -c 'echo /usr/local/bin/bash >> /etc/shells'` and `chsh -s /usr/local/bin/bash`
 
 The `mvn` tool might install the latest version of OpenJDK during the brew install. For builds on macOS to succeed,
-OpenJDK version 17 needs to be installed. This can be done by running `brew install openjdk@17`. For maven to read the
+OpenJDK version 21 needs to be installed. This can be done by running `brew install openjdk@21`. For maven to read the
 new Java version, you will need to edit the `~/.mavenrc` file and paste the following
-line `export JAVA_HOME=/Library/Java/JavaVirtualMachines/openjdk-17.jdk/Contents/Home`.
+line `export JAVA_HOME=/Library/Java/JavaVirtualMachines/openjdk-21.jdk/Contents/Home`.
 
 You may come across an issue of linking from the above step. To solve this run this command: 
-`sudo ln -sfn /usr/local/opt/openjdk@17/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk-17.jdk`.
+`sudo ln -sfn /usr/local/opt/openjdk@21/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk-21.jdk`.
 If this throws an error that it cannot find the file or directory, navigate into `/Library/Java/` (or however deep you
-can) and create a new folder named `JavaVirtualMachines` followed by creating a file named `openjdk-17.jdk`. The folder
-structure after everything is said and done should look like `/Library/Java/JavaVirtualMachines/openjdk-17.jdk`. After
+can) and create a new folder named `JavaVirtualMachines` followed by creating a file named `openjdk-21.jdk`. The folder
+structure after everything is said and done should look like `/Library/Java/JavaVirtualMachines/openjdk-21.jdk`. After
 doing that run the command at the beginning again and this should link the file and allow you to use maven with OpenJDK
-version 17.
+version 21.
 
 When running the tests, you may encounter `OpenSSL` related errors for parts that you may not have even worked on, in 
 which case you need to make sure you are using `OpenSSL` and not LibreSSL which comes by default with macOS.
@@ -246,7 +246,7 @@ Commonly used Make targets:
 
 ### Java versions
 
-Strimzi currently developed and tested with Java 17.
+Strimzi currently developed and tested with Java 21.
 
 ### Building Docker images
 

docker-images/base/Dockerfile

@@ -2,7 +2,7 @@ FROM registry.access.redhat.com/ubi9/ubi-minimal:latest
 
 LABEL org.opencontainers.image.source='https://github.com/strimzi/strimzi-kafka-operator'
 
-ARG JAVA_VERSION=17
+ARG JAVA_VERSION=21
 ARG TARGETOS
 ARG TARGETARCH
 ARG strimzi_version
@@ -21,7 +21,7 @@ RUN microdnf update -y \
     && microdnf reinstall -y tzdata \
     && microdnf clean all -y
 
-ENV JAVA_HOME=/usr/lib/jvm/jre-17
+ENV JAVA_HOME=/usr/lib/jvm/jre-${JAVA_VERSION}
 
 #####
 # Add Tini