From ef852789b2c156196a847b211066ae456c2683f5 Mon Sep 17 00:00:00 2001 From: Jan Srnicek Date: Tue, 27 Jun 2017 09:25:04 +0200 Subject: HONEYCOMB-358 - Activation module Provides module that provides set of distribution started modules Change-Id: I54287cc17f3af7d51a47a7342e5b8496e5ade00e Signed-off-by: Jan Srnicek --- .../distro/activation/ActiveModuleProvider.java | 150 +++++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 infra/minimal-distribution/src/main/java/io/fd/honeycomb/infra/distro/activation/ActiveModuleProvider.java (limited to 'infra/minimal-distribution/src/main/java/io/fd/honeycomb/infra/distro/activation/ActiveModuleProvider.java') diff --git a/infra/minimal-distribution/src/main/java/io/fd/honeycomb/infra/distro/activation/ActiveModuleProvider.java b/infra/minimal-distribution/src/main/java/io/fd/honeycomb/infra/distro/activation/ActiveModuleProvider.java new file mode 100644 index 000000000..21d108082 --- /dev/null +++ b/infra/minimal-distribution/src/main/java/io/fd/honeycomb/infra/distro/activation/ActiveModuleProvider.java @@ -0,0 +1,150 @@ +/* + * Copyright (c) 2017 Cisco and/or its affiliates. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package io.fd.honeycomb.infra.distro.activation; + +import com.google.common.collect.ImmutableList; +import com.google.inject.Inject; +import com.google.inject.Module; +import com.google.inject.Provider; +import java.io.File; +import java.io.IOException; +import java.net.URI; +import java.net.URISyntaxException; +import java.net.URL; +import java.nio.file.Files; +import java.nio.file.Path; +import java.nio.file.Paths; +import java.util.Collections; +import java.util.List; +import java.util.Set; +import java.util.stream.Collectors; +import java.util.stream.Stream; +import javax.annotation.Nonnull; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Provides list of active modules for distribution + */ +class ActiveModuleProvider implements Provider { + + private static final Logger LOG = LoggerFactory.getLogger(ActiveModuleProvider.class); + + @Inject + private ActivationConfig config; + + @Override + public ActiveModules get() { + return new ActiveModules(loadActiveModules( + aggregateResources(config.getModulesResourcePath(), Thread.currentThread().getContextClassLoader()))); + } + + /** + * Provide unique set of active modules filtered from provided resources + */ + static Set> loadActiveModules(@Nonnull final List moduleNames) { + final ClassLoader classLoader = ActiveModuleProvider.class.getClassLoader(); + LOG.info("Reading active modules configuration for distribution"); + + // process resources to resource modules + return moduleNames.stream() + .map(String::trim) + .filter(trimmedLine -> trimmedLine.length() != 0) + // filter out commented lines + .filter(nonEmptyLine -> !nonEmptyLine.startsWith("//")) + // filter duplicates + .distinct() + .map(validLine -> moduleNameToClass(validLine, classLoader)) + // filters out classes that are not modules + .filter(ActiveModuleProvider::filterNonModules) + .collect(Collectors.toSet()); + } + + /** + * Aggregate all resources from provided relative path into a {@code List} + */ + public static List aggregateResources(final String relativePath, final ClassLoader classLoader) { + try { + return Collections.list(classLoader.getResources(relativePath)).stream() + .map(ActiveModuleProvider::toURI) + .flatMap(ActiveModuleProvider::folderToFile) + .map(File::toURI) + .map(Paths::get) + // readAll lines and add them to iteration + .flatMap(ActiveModuleProvider::readLines) + .collect(Collectors.toList()); + } catch (IOException e) { + LOG.error("Unable to load resources from relative path {}", relativePath, e); + throw new IllegalStateException("Unable to load resources from relative path " + relativePath, e); + } + } + + private static Stream folderToFile(final URI uri) { + final File[] files = new File(uri).listFiles(File::isFile); + + return files != null + ? ImmutableList.copyOf(files).stream() + : Collections.emptyList().stream(); + } + + private static boolean filterNonModules(final Class clazz) { + final boolean isModule = Module.class.isAssignableFrom(clazz); + if (!isModule) { + LOG.warn("Class {} is provided in modules configuration, but is not a Module and will be ignored", clazz); + } + return isModule; + } + + /** + * Read lines from {@code Path} + */ + private static Stream readLines(final Path path) { + try { + return Files.readAllLines(path).stream(); + } catch (IOException e) { + LOG.error("Unable to read content of {}", path, e); + throw new IllegalStateException("Unable to read content of " + path, e); + } + } + + /** + * Converts {@code URL} to {@code URI} + */ + private static URI toURI(final URL url) { + try { + return url.toURI(); + } catch (URISyntaxException e) { + LOG.error("Unable to convert {} to uri", url); + throw new IllegalStateException("Unable to convert " + url + " to uri", e); + } + } + + /** + * Loads class by provided name + */ + private static Class moduleNameToClass(final String name, + final ClassLoader classLoader) { + try { + LOG.info("Loading module class {}", name); + return (Class) classLoader.loadClass(name); + } catch (ClassNotFoundException e) { + LOG.error("Unable to convert {} to class, make sure you've provided sources to classpath", name); + throw new IllegalStateException( + "Unable to convert " + name + " to class, make sure you've provided sources to classpath", e); + } + } +} -- cgit 1.2.3-korg