Introduce aarch64 packaging

[jasontedor]

This commit introduces aarch64 packaging, including bundling an aarch64 JDK distribution. We had to make some interesting choices here:

• ML binaries are not compiled for aarch64, so for now we disable ML on aarch64
• depending on underlying page sizes, we have to disable class data sharing

[mark-vieira]

Boy, just shows how much boilerplate is involved here. There's probably room for improvement there but luckily we don't add new distribution types very often. LGTM 👍

FYI, we'll need to adapt the DistributionDownloadPlugin to the notion of an architecture as well once we want to start testing.

[drewr]

Copy/paste error? I think these should be aarch64.

[jasontedor]

I pushed 80c24a0 directly to address this. Thanks for noticing.

[drewr]

Does the archiveClassifier also need to be updated? I thought it would be linux-aarch64.

[jasontedor]

Thanks again. 🤦‍♀

I pushed ba431a0.

[davidkyle]

There is also the native controller to consider.

elasticsearch/server/src/main/java/org/elasticsearch/bootstrap/Spawner.java

Line 61 in e036ac4

void spawnNativeControllers(final Environment environment) throws IOException {

It looks like the process is launched then dies immediately. There will be no sign of this in the logs as no code will try to connect to the controller because xpack.ml.enabled: false and the process failure is not logged.

Perhaps extend the property in plugin.descriptor.properties to has.native.controller.x64 and has.native.controller. aarch64 or simply don't don't spawn the controller on aarch64

[jasontedor]

@davidkyle The spawner today has support for architectures, and skips trying to fork the native controller when it doesn't exist:

elasticsearch/server/src/main/java/org/elasticsearch/plugins/Platforms.java

Lines 50 to 54 in 91462ee

	return plugin
	.resolve("platform")
	.resolve(PLATFORM_NAME)
	.resolve("bin")
	.resolve(PROGRAM_NAME);

elasticsearch/server/src/main/java/org/elasticsearch/plugins/Platforms.java

Line 88 in 91462ee

return normalizedOs + "-" + normalizedArch;

elasticsearch/server/src/main/java/org/elasticsearch/bootstrap/Spawner.java

Lines 75 to 78 in 91462ee

	final Path spawnPath = Platforms.nativeControllerPath(modules);
	if (!Files.isRegularFile(spawnPath)) {
	continue;
	}

This means that when run on aarch64, since there is not an ML native controller at x-pack-ml/platform/linux-aarch64/bin/controller, the spawner will not even attempt to fork a native controller.

[davidkyle]

👍 thanks for the explanation @jasontedor