Summary

Add --save-jlink-argfiles option to jlink.

Problem

The jlink tool can already be used to create a custom run-time image and jlink options such as those added by JDK-8232080 allow for branding the image (e.g. --vendor-version=AcmeVM 23.4) and baking in VM options (e.g., --add-options=-Dacme.version=23.4).

If the custom run-time image itself includes the jdk.jlink module, it can be desirable for such customization to be sticky. That is, it is automatically propagated into images created by the initial custom run-image.

Solution

Define a plugin to implement the desired jlink option persistence.

Specification

The new jlink plugin will implement the following option:

--save-jlink-argfiles=<filenames> saves the contents of <filenames> and prepends it as arguments to the execution of jlink in the output image. <filenames> is a : (; on Windows) separated path of command-line argument files.

$ jlink --list-plugins
  ...
  --save-jlink-argfiles <filenames>
                            Save the specified argument files that contain
                            the arguments to be prepended to the execution of
                            jlink in the output image. <filenames> is a
                            : (; on Windows) separated list of command-line argument files.

Example usage:

$ echo "--add-modules jdk.internal.vm.ci --add-options=-Dfoo=xyzzy --vendor-version=\"XyzzyVM 3.14.15\" --vendor-bug-url=https://bugs.xyzzy.com/" > /tmp/jre.argfile
$ export ALL_MODULES=$(java --list-modules | sed 's:@.*::g' | tr '\n' ',')
$ jlink --keep-packaged-modules=/tmp/jre/jmods --add-modules $ALL_MODULES --output=/tmp/jre --save-jlink-argfiles /tmp/jre.argfile @/tmp/jre.argfile
$ /tmp/jre/bin/java -XshowSettings:properties --version 2>&1 | grep yzzy
    foo = xyzzy
    java.vendor.url.bug = https://bugs.xyzzy.com/
    java.vendor.version = XyzzyVM 3.14.15
OpenJDK Runtime Environment XyzzyVM 3.14.15 (build 20-internal-2022-09-22-0951036)
OpenJDK 64-Bit Server VM XyzzyVM 3.14.15 (build 20-internal-2022-09-22-0951036, mixed mode)
$ /tmp/jre/bin/java -d jdk.internal.vm.ci | head -1
jdk.internal.vm.ci@20-internal
$ /tmp/jre/bin/jlink --add-modules=java.base --output=/tmp/jre2 --save-jlink-argfiles /tmp/jre.argfile
Error: --save-jlink-argfiles requires jdk.jlink to be in the output image
$ /tmp/jre/bin/jlink --add-modules=java.base --output=/tmp/jre2
$ /tmp/jre2/bin/java -XshowSettings:properties --version 2>&1 | grep yzzy
    foo = xyzzy
    java.vendor.url.bug = https://bugs.xyzzy.com/
    java.vendor.version = XyzzyVM 3.14.15
OpenJDK Runtime Environment XyzzyVM 3.14.15 (build 20-internal-2022-09-22-0951036.dnsimon...)
OpenJDK 64-Bit Server VM XyzzyVM 3.14.15 (build 20-internal-2022-09-22-0951036.dnsimon..., mixed mode)
$ /tmp/jre2/bin/java -d jdk.internal.vm.ci | head -1
jdk.internal.vm.ci@20-internal