Set up CI with JDK 21

Closes gh-37359

ci/images/ci-image-jdk21/Dockerfile

@@ -0,0 +1,11 @@
+FROM ubuntu:jammy-20230816
+
+ADD setup.sh /setup.sh
+ADD get-jdk-url.sh /get-jdk-url.sh
+ADD get-docker-url.sh /get-docker-url.sh
+ADD get-docker-compose-url.sh /get-docker-compose-url.sh
+RUN ./setup.sh java17 java21
+
+ENV JAVA_HOME /opt/openjdk
+ENV PATH $JAVA_HOME/bin:$PATH
+ADD docker-lib.sh /docker-lib.sh

ci/images/get-jdk-url.sh

@@ -14,6 +14,9 @@ case "$1" in
 	java20)
 		 echo "https://github.com/bell-sw/Liberica/releases/download/20.0.2+10/bellsoft-jdk20.0.2+10-linux-amd64.tar.gz"
 	;;
+	java21)
+		 echo "https://download.java.net/java/early_access/jdk21/25/GPL/openjdk-21-ea+25_linux-x64_bin.tar.gz"
+	;;
 	*)
 		echo $"Unknown java version"
 		exit 1

ci/pipeline.yml

@@ -187,6 +187,12 @@ resources:
   source:
     <<: *ci-registry-image-resource-source
     repository: ((docker-hub-organization))/spring-boot-ci-jdk20
+- name: ci-image-jdk21
+  type: registry-image
+  icon: docker
+  source:
+    <<: *ci-registry-image-resource-source
+    repository: ((docker-hub-organization))/spring-boot-ci-jdk21
 - name: paketo-builder-base-image
   type: registry-image
   icon: docker
@@ -235,6 +241,14 @@ resources:
     access_token: ((github-ci-status-token))
     branch: ((branch))
     context: jdk20-build
+- name: repo-status-jdk21-build
+  type: github-status-resource
+  icon: eye-check-outline
+  source:
+    repository: ((github-repo-name))
+    access_token: ((github-ci-status-token))
+    branch: ((branch))
+    context: jdk21-build
 - name: slack-alert
   type: slack-notification
   icon: slack
@@ -291,6 +305,13 @@ jobs:
         image: ci-image-jdk20
       vars:
         ci-image-name: ci-image-jdk20
+    - task: build-ci-image-jdk21
+      privileged: true
+      file: git-repo/ci/tasks/build-ci-image.yml
+      output_mapping:
+        image: ci-image-jdk21
+      vars:
+        ci-image-name: ci-image-jdk21
   - in_parallel:
     - put: ci-image
       params:
@@ -304,6 +325,9 @@ jobs:
     - put: ci-image-jdk20
       params:
         image: ci-image-jdk20/image.tar
+    - put: ci-image-jdk21
+      params:
+        image: ci-image-jdk21/image.tar
 - name: detect-jdk-updates
   plan:
   - get: git-repo
@@ -483,6 +507,38 @@ jobs:
     - put: slack-alert
       params:
         <<: *slack-success-params
+- name: jdk21-build
+  serial: true
+  public: true
+  plan:
+    - get: ci-image-jdk21
+    - get: git-repo
+      trigger: true
+    - put: repo-status-jdk21-build
+      params: { state: "pending", commit: "git-repo" }
+    - do:
+        - task: build-project
+          image: ci-image-jdk21
+          privileged: true
+          timeout: ((task-timeout))
+          file: git-repo/ci/tasks/build-project.yml
+          params:
+            BRANCH: ((branch))
+            TOOLCHAIN_JAVA_VERSION: 21
+            <<: *gradle-enterprise-task-params
+            <<: *docker-hub-task-params
+      on_failure:
+        do:
+          - put: repo-status-jdk21-build
+            params: { state: "failure", commit: "git-repo" }
+          - put: slack-alert
+            params:
+              <<: *slack-fail-params
+    - put: repo-status-jdk21-build
+      params: { state: "success", commit: "git-repo" }
+    - put: slack-alert
+      params:
+        <<: *slack-success-params
 - name: windows-build
   serial: true
   plan:
@@ -833,13 +889,42 @@ jobs:
     - put: slack-alert
       params:
         <<: *slack-success-params
+- name: jdk21-run-system-tests
+  serial: true
+  public: true
+  plan:
+    - get: ci-image-jdk21
+    - get: git-repo
+    - get: paketo-builder-base-image
+      trigger: true
+    - get: daily
+      trigger: true
+    - do:
+        - task: run-system-tests
+          image: ci-image-jdk21
+          privileged: true
+          timeout: ((task-timeout))
+          file: git-repo/ci/tasks/run-system-tests.yml
+          params:
+            BRANCH: ((branch))
+            TOOLCHAIN_JAVA_VERSION: 21
+            <<: *gradle-enterprise-task-params
+            <<: *docker-hub-task-params
+      on_failure:
+        do:
+          - put: slack-alert
+            params:
+              <<: *slack-fail-params
+    - put: slack-alert
+      params:
+        <<: *slack-success-params
 groups:
 - name: "builds"
-  jobs: ["build", "jdk11-build", "jdk17-build", "jdk20-build", "windows-build"]
+  jobs: ["build", "jdk11-build", "jdk17-build", "jdk20-build", "jdk21-build", "windows-build"]
 - name: "releases"
   jobs: ["stage-milestone", "stage-rc", "stage-release", "promote-milestone", "promote-rc", "promote-release", "create-github-release", "publish-gradle-plugin", "publish-to-sdkman", "update-homebrew-tap"]
 - name: "system-tests"
-  jobs: ["run-system-tests", "jdk11-run-system-tests", "jdk17-run-system-tests", "jdk20-run-system-tests"]
+  jobs: ["run-system-tests", "jdk11-run-system-tests", "jdk17-run-system-tests", "jdk20-run-system-tests", "jdk21-run-system-tests"]
 - name: "ci-images"
   jobs: ["build-ci-images", "detect-docker-updates", "detect-jdk-updates", "detect-ubuntu-image-updates"]