Java warnings when running Jenkins agents with Java 25

Bắt đầu bằng cách tái hiện cảnh báo từ Jenkins agent của systemd đang chạy /usr/bin/java với agent.jar, sau đó lần theo đường khởi động com.sun.jna.Native được hiển thị trong log. Kiểm tra xem cảnh báo có cần được xử lý đối với Java 25 hoặc các bản phát hành trong tương lai hay không; công việc được xem là hoàn tất khi một biện pháp giảm thiểu cho thiết lập agent đã được ghi lại hoặc xác thực.

e.g.

root@test-hetzner-ubuntu2404-x64-1 ~ # java -version
openjdk version "25.0.3" 2026-04-21
OpenJDK Runtime Environment (build 25.0.3+9-2-24.04.2-Ubuntu)
OpenJDK 64-Bit Server VM (build 25.0.3+9-2-24.04.2-Ubuntu, mixed mode, sharing)
root@test-hetzner-ubuntu2404-x64-1 ~ # systemctl status jenkins.service
● jenkins.service - Jenkins agent
     Loaded: loaded (/usr/lib/systemd/system/jenkins.service; enabled; preset: enabled)
     Active: active (running) since Tue 2026-06-09 06:50:43 CEST; 9h ago
   Main PID: 84335 (java)
      Tasks: 36 (limit: 76800)
     Memory: 201.5M (peak: 203.4M)
        CPU: 2min 54.671s
     CGroup: /system.slice/jenkins.service
             └─84335 /usr/bin/java -Xmx128m -jar /home/iojs/agent.jar -url https://ci.nodejs.org -name test-hetzner-ubuntu2404-x64-1 -secret e357745ed8badc1076eb653e7506902403e5c2e6f68e994f082e7685dc50a236

Jun 09 06:50:44 test-hetzner-ubuntu2404-x64-1 java[84335]: Jun 09, 2026 6:50:44 AM org.jenkinsci.remoting.protocol.impl.BIONetworkLayer$Reader run
Jun 09 06:50:44 test-hetzner-ubuntu2404-x64-1 java[84335]: INFO: Waiting for ProtocolStack to start.
Jun 09 06:50:45 test-hetzner-ubuntu2404-x64-1 java[84335]: Jun 09, 2026 6:50:45 AM hudson.remoting.Launcher$CuiListener status
Jun 09 06:50:45 test-hetzner-ubuntu2404-x64-1 java[84335]: INFO: Remote identity confirmed: 4f:22:06:c2:64:29:f3:3f:6d:7c:d7:01:f2:18:bb:93
Jun 09 06:50:45 test-hetzner-ubuntu2404-x64-1 java[84335]: Jun 09, 2026 6:50:45 AM hudson.remoting.Launcher$CuiListener status
Jun 09 06:50:45 test-hetzner-ubuntu2404-x64-1 java[84335]: INFO: Connected
Jun 09 06:51:01 test-hetzner-ubuntu2404-x64-1 java[84335]: WARNING: A restricted method in java.lang.System has been called
Jun 09 06:51:01 test-hetzner-ubuntu2404-x64-1 java[84335]: WARNING: java.lang.System::load has been called by com.sun.jna.Native in an unnamed module
Jun 09 06:51:01 test-hetzner-ubuntu2404-x64-1 java[84335]: WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
Jun 09 06:51:01 test-hetzner-ubuntu2404-x64-1 java[84335]: WARNING: Restricted methods will be blocked in a future release unless native access is enabled
root@test-hetzner-ubuntu2404-x64-1 ~ #

I don't think this causes us problems today, but may be a problem with a "future release" of Java.