nixos/jenkins: Introduce javaPackage option; Bump Java version to 21 (#412480)

nixos/modules/services/continuous-integration/jenkins/default.nix

@@ -11,13 +11,7 @@ in
 {
   options = {
     services.jenkins = {
-      enable = lib.mkOption {
-        type = lib.types.bool;
-        default = false;
-        description = ''
-          Whether to enable the jenkins continuous integration server.
-        '';
-      };
+      enable = lib.mkEnableOption "Jenkins, a continuous integration server";
 
       user = lib.mkOption {
         default = "jenkins";
@@ -89,11 +83,13 @@ in
 
       package = lib.mkPackageOption pkgs "jenkins" { };
 
+      javaPackage = lib.mkPackageOption pkgs "jdk21" { };
+
       packages = lib.mkOption {
         default = [
           pkgs.stdenv
           pkgs.git
-          pkgs.jdk17
+          pkgs.jdk21
           config.programs.ssh.package
           pkgs.nix
         ];
@@ -239,7 +235,7 @@ in
 
       # For reference: https://wiki.jenkins.io/display/JENKINS/JenkinsLinuxStartupScript
       script = ''
-        ${pkgs.jdk17}/bin/java ${lib.concatStringsSep " " cfg.extraJavaOptions} -jar ${cfg.package}/webapps/jenkins.war --httpListenAddress=${cfg.listenAddress} \
+        ${cfg.javaPackage}/bin/java ${lib.concatStringsSep " " cfg.extraJavaOptions} -jar ${cfg.package}/webapps/jenkins.war --httpListenAddress=${cfg.listenAddress} \
                                                   --httpPort=${toString cfg.port} \
                                                   --prefix=${cfg.prefix} \
                                                   -Djava.awt.headless=true \

pkgs/by-name/je/jenkins/package.nix

@@ -8,7 +8,7 @@
   gnused,
   makeWrapper,
   nix,
-  openjdk,
+  jdk21,
   writeScript,
   nixosTests,
   jq,
@@ -33,10 +33,10 @@ stdenv.mkDerivation (finalAttrs: {
     cp "$src" "$out/webapps/jenkins.war"
 
     # Create the `jenkins-cli` command.
-    ${openjdk}/bin/jar -xf "$src" WEB-INF/lib/cli-${finalAttrs.version}.jar \
+    ${jdk21}/bin/jar -xf "$src" WEB-INF/lib/cli-${finalAttrs.version}.jar \
       && mv WEB-INF/lib/cli-${finalAttrs.version}.jar "$out/share/jenkins-cli.jar"
 
-    makeWrapper "${openjdk}/bin/java" "$out/bin/jenkins-cli" \
+    makeWrapper "${jdk21}/bin/java" "$out/bin/jenkins-cli" \
       --add-flags "-jar $out/share/jenkins-cli.jar"
   '';