(1). 概述
前面,对:NodeEnvironment进行了分析,这一节主要分析:PluginsService.
(2). Node
protected Node(
final Environment environment,
Collection<Class<? extends Plugin>> classpathPlugins,
boolean forbidPrivateIndexSettings) {
// tmpSettings = {
// "cluster.name" : "elasticsearch",
// "http.cors.allow-origin" : "*",
// "http.cors.enabled" : "true",
// "node.name" : "lixin-macbook.local",
// "path.home" : "/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0",
// "path.logs" : "/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/logs",
// "client.type" : "node"
// }
// TODO ... ...
// *********************************************************************************
// 创建插件服务
// *********************************************************************************
this.pluginsService =
new PluginsService(
tmpSettings,
// 配置文件所在目录
// /Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/config
environment.configFile(),
// 模块所在目录
// /Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules
environment.modulesFile(),
// 插件所在目录
// /Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/plugins
environment.pluginsFile(),
// 空的集合.
classpathPlugins);
// 读取所有插件的:additionalSettings/getFeature中的配置信息
// 更新到: settings
// settings = {
// "client.type" : "node",
// "cluster.name" : "elasticsearch",
// "http.cors.allow-origin" : true,
// "http.cors.enabled" : true,
// "node.attr.ml.machine_memory" : "8589934592",
// "node.attr.ml.max_open_jobs" : "20",
// "node.attr.xpack.installed" : true,
// "node.name" : "lixin-macbook.local",
// "path.home" : "/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0",
// "path.logs" : "/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/logs",
// "transport.features.x-pack" : true,
// "http.type" : "security4",
// "http.type.default" : "netty4",
// "transport.type" : "security4" ,
// "transport.type.default" : "netty4"
// }
this.settings = pluginsService.updatedSettings();
// TODO ... ...
}
(3). PluginsService
public class PluginsService {
private final Settings settings;
private final Path configPath;
private final List<Tuple<PluginInfo, Plugin>> plugins;
private final PluginsAndModules info;
public PluginsService(
Settings settings,
// /Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/config
Path configPath,
// /Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules
Path modulesDirectory,
// /Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/plugins
Path pluginsDirectory,
// []空的集合
Collection<Class<? extends Plugin>> classpathPlugins
) {
this.settings = settings;
this.configPath = configPath;
List<Tuple<PluginInfo, Plugin>> pluginsLoaded = new ArrayList<>();
List<PluginInfo> pluginsList = new ArrayList<>();
final List<String> pluginsNames = new ArrayList<>();
// classpathPlugins = []
for (Class<? extends Plugin> pluginClass : classpathPlugins) {
Plugin plugin = loadPlugin(pluginClass, settings, configPath);
PluginInfo pluginInfo = new PluginInfo(pluginClass.getName(), "classpath plugin", "NA", Version.CURRENT, "1.8",
pluginClass.getName(), Collections.emptyList(), false);
if (logger.isTraceEnabled()) {
logger.trace("plugin loaded from classpath [{}]", pluginInfo);
}
pluginsLoaded.add(new Tuple<>(pluginInfo, plugin));
pluginsList.add(pluginInfo);
pluginsNames.add(pluginInfo.getName());
} // end for
// ********************************************************
// 加载:modules目录下所有的:molue
// 这个时候,实际并没有对插件初始化.
// ********************************************************
Set<Bundle> seenBundles = new LinkedHashSet<>();
List<PluginInfo> modulesList = new ArrayList<>();
// load modules
if (modulesDirectory != null) { // false
try {
// ********************************************************
// 4.加载模块(PluginsService.getModuleBundles)
// ********************************************************
Set<Bundle> modules = getModuleBundles(modulesDirectory);
for (Bundle bundle : modules) {
// modulesList 存储:pluginInfo对象
modulesList.add(bundle.plugin);
}
// seenBundles存储:所有的:Bundle
seenBundles.addAll(modules);
} catch (IOException ex) {
throw new IllegalStateException("Unable to initialize modules", ex);
}
} // end load modules
// *******************************************************
// 加载插件目录下的所有文件转换成:Bundle
// *******************************************************
// pluginDirectory = "/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/plugins"
if (pluginsDirectory != null) {
try {
// 测试下目录是否可读
if (isAccessibleDirectory(pluginsDirectory, logger)) {
// 检查目录下:.removing-这样的文件
checkForFailedPluginRemovals(pluginsDirectory);
// 加载插件与Modules加载方式一样,不往下分析,可以断点的一点就是:在这个时候:
// 插件(jar)里的对象并没有初始化.
Set<Bundle> plugins = getPluginBundles(pluginsDirectory);
for (final Bundle bundle : plugins) {
// pluginsList 存储: PluginInfo对象
pluginsList.add(bundle.plugin);
// pluginsNames 存储: 配置文件中指定的名称.
pluginsNames.add(bundle.plugin.getName());
}
// 所有的插件.
seenBundles.addAll(plugins);
}
} catch (IOException ex) {
throw new IllegalStateException("Unable to initialize plugins", ex);
}
}// end load plugins
// ***********************************************************************
// **************** PluginsService.loadBundle比较重要.***************
// 1. 通过创建:ClassLoader加载jar
// 2. 根据配置文件(plugin-descriptor.properties)中的配置
// [classname=org.elasticsearch.percolator.PercolatorPlugin]
// 3. ClassLoader加载这个Class(PercolatorPlugin),PercolatorPlugin必须要是:Plugin的子类.
// loader.loadClass(className).asSubclass(Plugin.class);
// 4. 自定义Plugin的构造器只能有三种情况(path:/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/config目录):
// 4.1 PercolatorPlugin(Settings,Path)
// 4.2 PercolatorPlugin(Settings)
// 4.3 PercolatorPlugin()
// 5. 自定义Plugin如果不满足以上情况,则会抛出IllegalStateException异常.
// ***********************************************************************
List<Tuple<PluginInfo, Plugin>> loaded = loadBundles(seenBundles);
pluginsLoaded.addAll(loaded);
// PluginsAndModules执有:module/plugin的所有:PluginInfo信息,估计是为了方便索引
this.info = new PluginsAndModules(pluginsList, modulesList);
// 初始化后的所有模块和插件,是一个二无组,转换成不可修改集合二元组.
// 这是不是意味着:不支持热部署哈.
this.plugins = Collections.unmodifiableList(pluginsLoaded);
// Checking expected plugins
List<String> mandatoryPlugins = MANDATORY_SETTING.get(settings);
if (mandatoryPlugins.isEmpty() == false) { // false
Set<String> missingPlugins = new HashSet<>();
for (String mandatoryPlugin : mandatoryPlugins) {
if (!pluginsNames.contains(mandatoryPlugin) && !missingPlugins.contains(mandatoryPlugin)) {
missingPlugins.add(mandatoryPlugin);
}
}
if (!missingPlugins.isEmpty()) {
final String message = String.format(
Locale.ROOT,
"missing mandatory plugins [%s], found plugins [%s]",
Strings.collectionToDelimitedString(missingPlugins, ", "),
Strings.collectionToDelimitedString(pluginsNames, ", "));
throw new IllegalStateException(message);
}
} // end if
// 打印日志( loaded module [xxxxx] )
logPluginInfo(info.getModuleInfos(), "module", logger);
logPluginInfo(info.getPluginInfos(), "plugin", logger);
}// end PluginsService 构造器
}// end PluginsService
(4). PluginsService.getModuleBundles
// 4.1. 加载modules
// getModuleBundles
// modulesDirectory = "/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules"
static Set<Bundle> getModuleBundles(Path modulesDirectory) throws IOException {
// ***********************************************************
// 4.2. 调用:findBundles
// ***********************************************************
return findBundles(modulesDirectory, "module");
}// end
// 4.2. findBundles声明
private static Set<Bundle> findBundles(final Path directory, String type) throws IOException {
// path = "/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules"
// type = "module"
final Set<Bundle> bundles = new HashSet<>();
// ******************************************************
// 4.3. findPluginDirs
// ******************************************************
for (final Path plugin : findPluginDirs(directory)) {
// plugin为modules下的目录
// ****************************************************************
// 5. PluginsService.readPluginBundle
// 此处以percolator插件为例:
// /Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules/percolator
// 读取插件所有的目录,并转换成:Bundle.
// ****************************************************************
final Bundle bundle = readPluginBundle(bundles, plugin, type);
bundles.add(bundle);
}
return bundles;
}// end findBundles
// 4.3 findPluginDirs声明
// 加载目录:/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules下所有的目录
public static List<Path> findPluginDirs(final Path rootPath) throws IOException {
// [
// "/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules/percolator" ,
// "/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules/reindex" ,
// "/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules/analysis-common"
// ]
final List<Path> plugins = new ArrayList<>();
// percolator = [ "percolator","reindex","analysis-common" ]
final Set<String> seen = new HashSet<>();
if (Files.exists(rootPath)) {
try (DirectoryStream<Path> stream = Files.newDirectoryStream(rootPath)) {
for (Path plugin : stream) {
if (FileSystemUtils.isDesktopServicesStore(plugin) ||
plugin.getFileName().toString().startsWith(".removing-")) {
continue;
}
if (seen.add(plugin.getFileName().toString()) == false) {
throw new IllegalStateException("duplicate plugin: " + plugin);
}
plugins.add(plugin);
}
}
}
return plugins;
}// end findPluginDirs
(5). PluginsService.readPluginBundle
读取插件信息
private static Bundle readPluginBundle(
// []空集合
final Set<Bundle> bundles,
// plugin = "/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules/percolator"
final Path plugin,
// type = "module"
String type) throws IOException {
LogManager.getLogger(PluginsService.class).trace("--- adding [{}] [{}]", type, plugin.toAbsolutePath());
final PluginInfo info;
try {
// *******************************************************
// 6. 读取插件目录下的配置文件: PluginInfo.readFromProperties
// *******************************************************
info = PluginInfo.readFromProperties(plugin);
} catch (final IOException e) {
throw new IllegalStateException("Could not load plugin descriptor for " + type +
" directory [" + plugin.getFileName() + "]", e);
}
// *****************************************************
// 7. 根据:PluginInfo对象,构建成:PluginsService$Bundle
// Bundle包含一个PluginInfo和一堆Jar包.
// *****************************************************
final Bundle bundle = new Bundle(info, plugin);
// 添加到临时集合中.
if (bundles.add(bundle) == false) {
throw new IllegalStateException("duplicate " + type + ": " + info);
}
return bundle;
}
(6). PluginInfo.readFromProperties
读取插件目录下的配置文件,并转换成:PluginInfo对象.
// 查看插件下的:plugin-descriptor.properties
lixin-macbook:percolator lixin$ cat /Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules/percolator/plugin-descriptor.properties
version=7.1.0
name=percolator
classname=org.elasticsearch.percolator.PercolatorPlugin
java.version=1.8
elasticsearch.version=7.1.0
extended.plugins=
has.native.controller=false
readFromProperties读取插件目录下的配置文件,并转换成:PluginInfo对象.
public static PluginInfo readFromProperties(final Path path) throws IOException {
// ES_PLUGIN_PROPERTIES = "plugin-descriptor.properties";
// /Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules/percolator/plugin-descriptor.properties
final Path descriptor = path.resolve(ES_PLUGIN_PROPERTIES);
final Map<String, String> propsMap;
{
final Properties props = new Properties();
// 读取配置文件
try (InputStream stream = Files.newInputStream(descriptor)) {
props.load(stream);
}
// 将配置文件内容转换到:propsMap里
propsMap = props.stringPropertyNames().stream().collect(Collectors.toMap(Function.identity(), props::getProperty));
}
// 从配置文件中移除一项:name
// name = "percolator"
final String name = propsMap.remove("name");
if (name == null || name.isEmpty()) {
throw new IllegalArgumentException(
"property [name] is missing in [" + descriptor + "]");
}
// description = "Percolator module adds capability to index queries and query these queries by specifying documents"
final String description = propsMap.remove("description");
if (description == null) {
throw new IllegalArgumentException(
"property [description] is missing for plugin [" + name + "]");
}
// version = "7.1.0"
final String version = propsMap.remove("version");
if (version == null) {
throw new IllegalArgumentException(
"property [version] is missing for plugin [" + name + "]");
}
// esVersionString = "7.1.0"
final String esVersionString = propsMap.remove("elasticsearch.version");
if (esVersionString == null) {
throw new IllegalArgumentException(
"property [elasticsearch.version] is missing for plugin [" + name + "]");
}
// 对字符串进行解析成:Vesion
final Version esVersion = Version.fromString(esVersionString);
// java.version = "1.8"
final String javaVersionString = propsMap.remove("java.version");
if (javaVersionString == null) {
throw new IllegalArgumentException(
"property [java.version] is missing for plugin [" + name + "]");
}
// 检查jdk版本
JarHell.checkVersionFormat(javaVersionString);
// classname = "org.elasticsearch.percolator.PercolatorPlugin"
final String classname = propsMap.remove("classname");
if (classname == null) {
throw new IllegalArgumentException(
"property [classname] is missing for plugin [" + name + "]");
}
// extended.plugins = ""
// 扩展插件以逗号分隔.
final String extendedString = propsMap.remove("extended.plugins");
final List<String> extendedPlugins;
if (extendedString == null) {
extendedPlugins = Collections.emptyList();
} else {
extendedPlugins = Arrays.asList(Strings.delimitedListToStringArray(extendedString, ","));
}
// has.native.controller = fasle
final String hasNativeControllerValue = propsMap.remove("has.native.controller");
final boolean hasNativeController;
if (hasNativeControllerValue == null) {
hasNativeController = false;
} else {
switch (hasNativeControllerValue) {
case "true":
hasNativeController = true;
break;
case "false": // true
hasNativeController = false;
break;
default:
final String message = String.format(
Locale.ROOT,
"property [%s] must be [%s], [%s], or unspecified but was [%s]",
"has_native_controller",
"true",
"false",
hasNativeControllerValue);
throw new IllegalArgumentException(message);
}
}
// 针对6.0.0 ~ 6.3.0 删除: requires.keystore
if (esVersion.before(Version.V_6_3_0) && esVersion.onOrAfter(Version.V_6_0_0_beta2)) {
propsMap.remove("requires.keystore");
}
// 如果propsMap还有内容(多的配置项),则抛出异常.
// 看来配置项只能是这几项,否则,抛出异常.所以
// 这也是为什么从配置文件变成Map,不是从Map中读取数据,而是一项一项的remove.
if (propsMap.isEmpty() == false) {
throw new IllegalArgumentException("Unknown properties in plugin descriptor: " + propsMap.keySet());
}
// 构建:PluginInfo
return new PluginInfo(name, description, version, esVersion, javaVersionString,
classname, extendedPlugins, hasNativeController);
}
(7). PluginsService$Bundle
Bundle为一个组件,它包含:PluginInfo和所有的Jar包.
static class Bundle {
final PluginInfo plugin;
final Set<URL> urls;
Bundle(PluginInfo plugin, Path dir) throws IOException {
// plugin = { "name" : "percolator" , "classname" : "org.elasticsearch.percolator.PercolatorPlugin" }
// dir = "/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules/percolator"
this.plugin = Objects.requireNonNull(plugin);
Set<URL> urls = new LinkedHashSet<>();
// gather urls for jar files
// 过滤目录下:/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules/percolator
// 所有jar文件
try (DirectoryStream<Path> jarStream = Files.newDirectoryStream(dir, "*.jar")) {
for (Path jar : jarStream) {
// file:/Users/lixin/Developer/elastic-search/elasticsearch-7.1.0/modules/percolator/percolator-client-7.1.0.jar
URL url = jar.toRealPath().toUri().toURL();
// 添加到临时集合中
if (urls.add(url) == false) {
throw new IllegalStateException("duplicate codebase: " + url);
}
}
}
this.urls = Objects.requireNonNull(urls);
} //end 构造器
}
(8). 总结
PluginsService加载所有的modules和plugins.
