🐛 Adding settings to the init script for jdtls

Dockerfile

@@ -5,6 +5,8 @@ RUN curl -s -o jdtls.tar.gz https://download.eclipse.org/jdtls/milestones/1.36.0
 	chmod 755 /jdtls/bin/jdtls &&\
         rm -rf jdtls.tar.gz
 
+COPY jdtls-bin-override/jdtls.py /jdtls/bin/jdtls.py
+
 FROM registry.access.redhat.com/ubi9/ubi AS maven-index
 COPY hack/maven.default.index /maven.default.index
 FROM registry.access.redhat.com/ubi9/ubi AS fernflower

jdtls-bin-override/jdtls.py

@@ -0,0 +1,114 @@
+###############################################################################
+# Copyright (c) 2022 Marc Schreiber and others.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Eclipse Public License 2.0 which is available at
+# http://www.eclipse.org/legal/epl-2.0.
+#
+# SPDX-License-Identifier: EPL-2.0
+#
+# Contributors:
+# Marc Schreiber - initial API and implementation
+###############################################################################
+import argparse
+from hashlib import sha1
+import os
+import platform
+import re
+import subprocess
+from pathlib import Path
+import tempfile
+
+def get_java_executable(known_args):
+	if known_args.java_executable is not None:
+		java_executable = known_args.java_executable
+	else:
+		java_executable = 'java'
+
+		if 'JAVA_HOME' in os.environ:
+			ext = '.exe' if platform.system()  == 'Windows' else ''
+			java_exec_to_test = Path(os.environ['JAVA_HOME']) / 'bin' / f'java{ext}'
+			if java_exec_to_test.is_file():
+				java_executable = java_exec_to_test.resolve()
+
+	if not known_args.validate_java_version:
+		return java_executable
+
+	out = subprocess.check_output([java_executable, '-version'], stderr = subprocess.STDOUT, universal_newlines=True)
+
+	matches = re.finditer(r"(?<=version\s\")(?P<major>\d+)(\.\d+\.\d+(_\d+)?)?", out)
+	for match in matches:
+		java_major_version = int(match.group("major"))
+
+		if java_major_version < 17:
+			raise Exception("jdtls requires at least Java 17")
+
+		return java_executable
+
+	raise Exception("Could not determine Java version")
+
+def find_equinox_launcher(jdtls_base_directory):
+	plugins_dir = jdtls_base_directory / "plugins"
+	launchers = plugins_dir.glob('org.eclipse.equinox.launcher_*.jar')
+	for launcher in launchers:
+		return plugins_dir / launcher
+
+	raise Exception("Cannot find equinox launcher")
+
+def get_shared_config_path(jdtls_base_path):
+	system = platform.system()
+
+	if system in ['Linux', 'FreeBSD']:
+		config_dir = 'config_linux'
+	elif system == 'Darwin':
+		config_dir = 'config_mac'
+	elif system == 'Windows':
+		config_dir = 'config_win'
+	else:
+		raise Exception("Unknown platform {} detected".format(system))
+
+	return jdtls_base_path / config_dir
+
+def main(args):
+	cwd_name = os.path.basename(os.getcwd())
+	jdtls_data_path = os.path.join(tempfile.gettempdir(), "jdtls-" + sha1(cwd_name.encode()).hexdigest())
+
+	parser = argparse.ArgumentParser()
+	parser.add_argument('--validate-java-version', action='store_true', default=True)
+	parser.add_argument('--no-validate-java-version', dest='validate_java_version', action='store_false')
+	parser.add_argument("--java-executable", help="Path to java executable used to start runtime.")
+	parser.add_argument("--jvm-arg",
+			default=[],
+			action="append",
+			help="An additional JVM option (can be used multiple times. Note, use with equal sign. For example: --jvm-arg=-Dlog.level=ALL")
+	parser.add_argument("-data", default=jdtls_data_path)
+
+	known_args, args = parser.parse_known_args(args)
+	java_executable = get_java_executable(known_args)
+
+	jdtls_base_path = Path(__file__).parent.parent
+	shared_config_path = get_shared_config_path(jdtls_base_path)
+	jar_path = find_equinox_launcher(jdtls_base_path)
+
+	system = platform.system()
+	exec_args = ["-Declipse.application=org.eclipse.jdt.ls.core.id1",
+			"-Dosgi.bundles.defaultStartLevel=4",
+			"-Declipse.product=org.eclipse.jdt.ls.core.product",
+			"-Dosgi.checkConfiguration=true",
+			"-Dosgi.sharedConfiguration.area=" + str(shared_config_path),
+			"-Dosgi.sharedConfiguration.area.readOnly=true",
+			"-Dosgi.configuration.cascaded=true",
+			"-Xms1g",
+			'-XX:MaxRAMPercentage=70.0',
+			"--add-modules=ALL-SYSTEM",
+			"--add-opens", "java.base/java.util=ALL-UNNAMED",
+			"--add-opens", "java.base/java.lang=ALL-UNNAMED"] \
+			+ known_args.jvm_arg \
+			+ ["-jar", jar_path,
+			"-data", known_args.data] \
+			+ args
+
+	if os.name == 'posix':
+		os.execvp(java_executable, exec_args)
+	else:
+		subprocess.run([java_executable] + exec_args)