Soul网关源码阅读（九）插件配置加载初探

简介

今日来探索一下插件的初始化，及相关的配置的加载

源码Debug

插件初始化

首先来到我们非常熟悉的插件链调用的类： SoulWebHandler ,在其中的 DefaultSoulPluginChain ,我们看到plugins是通过构造函数传入的

我们来跟踪一下是谁传入的，在SoulWebHandler的public那一行打上断点，重启后跟踪调用栈

public final class SoulWebHandler implements WebHandler {private final List<SoulPlugin> plugins;// 在这里也看到plugins是通过构造函数传入的，在public这一行打上断点，然后重启public SoulWebHandler(final List<SoulPlugin> plugins) {this.plugins = plugins;String schedulerType = System.getProperty("soul.scheduler.type", "fixed");if (Objects.equals(schedulerType, "fixed")) {int threads = Integer.parseInt(System.getProperty("soul.work.threads", "" + Math.max((Runtime.getRuntime().availableProcessors() << 1) + 1, 16)));scheduler = Schedulers.newParallel("soul-work-threads", threads);} else {scheduler = Schedulers.elastic();}}@Overridepublic Mono<Void> handle(@NonNull final ServerWebExchange exchange) {MetricsTrackerFacade.getInstance().counterInc(MetricsLabelEnum.REQUEST_TOTAL.getName());Optional<HistogramMetricsTrackerDelegate> startTimer = MetricsTrackerFacade.getInstance().histogramStartTimer(MetricsLabelEnum.REQUEST_LATENCY.getName());// 传入 plugins 到 DefaultSoulPluginChainreturn new DefaultSoulPluginChain(plugins).execute(exchange).subscribeOn(scheduler).doOnSuccess(t -> startTimer.ifPresent(time -> MetricsTrackerFacade.getInstance().histogramObserveDuration(time)));}private static class DefaultSoulPluginChain implements SoulPluginChain {private int index;private final List<SoulPlugin> plugins;// 通过构造函数得到 pluginsDefaultSoulPluginChain(final List<SoulPlugin> plugins) {this.plugins = plugins;}@Overridepublic Mono<Void> execute(final ServerWebExchange exchange) {return Mono.defer(() -> {if (this.index < plugins.size()) {SoulPlugin plugin = plugins.get(this.index++);Boolean skip = plugin.skip(exchange);if (skip) {return this.execute(exchange);}return plugin.execute(exchange, this);}return Mono.empty();});}}
}

我这有点慢，重启等以后后，我们查看上一个调用，来到了 SoulConfiguration

通过类的大致信息可以看到是Spring之类的加载机制。通过前面文章的分析中，大致应该就是配置了 auto configuration ，然后启动的时候Spring进行加载的

public class SoulConfiguration {@Bean("webHandler")public SoulWebHandler soulWebHandler(final ObjectProvider<List<SoulPlugin>> plugins) {List<SoulPlugin> pluginList = plugins.getIfAvailable(Collections::emptyList);final List<SoulPlugin> soulPlugins = pluginList.stream().sorted(Comparator.comparingInt(SoulPlugin::getOrder)).collect(Collectors.toList());soulPlugins.forEach(soulPlugin -> log.info("load plugin:[{}] [{}]", soulPlugin.named(), soulPlugin.getClass().getName()));return new SoulWebHandler(soulPlugins);}
}

大致就知道是Spring自动加载的，通过AutoConfiguration机制，下面就是Spring相关了，这里就不继续跟踪了

配置初始化

在上一篇的文章分析中，我们分析了路由匹配的大致细节，需要选择器和规则的配置，下面我们来跟踪一下这些配置的初始化

首先进入路由匹配核心类： AbstractSoulPlugin ，其中进行 pluginData 、selectorData、rules的获取，如下面代码注释：

public abstract class AbstractSoulPlugin implements SoulPlugin {@Overridepublic Mono<Void> execute(final ServerWebExchange exchange, final SoulPluginChain chain) {String pluginName = named();// 获取插件数据final PluginData pluginData = BaseDataCache.getInstance().obtainPluginData(pluginName);if (pluginData != null && pluginData.getEnabled()) {// 根据插件名称，获取选择器数据final Collection<SelectorData> selectors = BaseDataCache.getInstance().obtainSelectorData(pluginName);if (CollectionUtils.isEmpty(selectors)) {return handleSelectorIsNull(pluginName, exchange, chain);}final SelectorData selectorData = matchSelector(exchange, selectors);if (Objects.isNull(selectorData)) {return handleSelectorIsNull(pluginName, exchange, chain);}selectorLog(selectorData, pluginName);// 根据选择器的id，获取其规则数据final List<RuleData> rules = BaseDataCache.getInstance().obtainRuleData(selectorData.getId());if (CollectionUtils.isEmpty(rules)) {return handleRuleIsNull(pluginName, exchange, chain);}RuleData rule;if (selectorData.getType() == SelectorTypeEnum.FULL_FLOW.getCode()) {rule = rules.get(rules.size() - 1);} else {rule = matchRule(exchange, rules);}if (Objects.isNull(rule)) {return handleRuleIsNull(pluginName, exchange, chain);}ruleLog(rule, pluginName);return doExecute(exchange, chain, selectorData, rule);}return chain.execute(exchange);}
}

我们到这个类： BaseDataCache 看一下，看到它有两个数据的Map存储：插件数据、选择器数据、规则数据

public final class BaseDataCache {/*** pluginName -> PluginData.*/private static final ConcurrentMap<String, PluginData> PLUGIN_MAP = Maps.newConcurrentMap();/*** pluginName -> SelectorData.*/private static final ConcurrentMap<String, List<SelectorData>> SELECTOR_MAP = Maps.newConcurrentMap();/*** selectorId -> RuleData.*/private static final ConcurrentMap<String, List<RuleData>> RULE_MAP = Maps.newConcurrentMap();}

我们发现它是一个静态单例，而插件数据的配置是使用下面的函数，我们在函数上打上断点，看看是谁调用了它，它的调用栈是怎么样的

public final class BaseDataCache {public void cachePluginData(final PluginData pluginData) {Optional.ofNullable(pluginData).ifPresent(data -> PLUGIN_MAP.put(data.getName(), data));}
}

在public这一行打上断点，重启，顺利进入上面的函数，我们查看下 pluginData ，还挺简单，大致如下

PluginData(id=1, name=sign, config=null, role=1, enabled=false)

我们跟踪其调用栈，其调用链的类和函数如下，类在调用栈的顺序也是对应的

public class CommonPluginDataSubscriber implements PluginDataSubscriber {// 在这个里面触发 subscribeDataHandler , subscribeDataHandler 触发 DaseDataCache的调用@Overridepublic void onSubscribe(final PluginData pluginData) {subscribeDataHandler(pluginData, DataEventTypeEnum.UPDATE);}private <T> void subscribeDataHandler(final T classData, final DataEventTypeEnum dataType) {Optional.ofNullable(classData).ifPresent(data -> {// 插件数据的操作if (data instanceof PluginData) {PluginData pluginData = (PluginData) data;if (dataType == DataEventTypeEnum.UPDATE) {// 在这进行触发调用BaseDataCache.getInstance().cachePluginData(pluginData);Optional.ofNullable(handlerMap.get(pluginData.getName())).ifPresent(handler -> handler.handlerPlugin(pluginData));} else if (dataType == DataEventTypeEnum.DELETE) {BaseDataCache.getInstance().removePluginData(pluginData);Optional.ofNullable(handlerMap.get(pluginData.getName())).ifPresent(handler -> handler.removePlugin(pluginData));}// 选择器的操作} else if (data instanceof SelectorData) {SelectorData selectorData = (SelectorData) data;if (dataType == DataEventTypeEnum.UPDATE) {BaseDataCache.getInstance().cacheSelectData(selectorData);Optional.ofNullable(handlerMap.get(selectorData.getPluginName())).ifPresent(handler -> handler.handlerSelector(selectorData));} else if (dataType == DataEventTypeEnum.DELETE) {BaseDataCache.getInstance().removeSelectData(selectorData);Optional.ofNullable(handlerMap.get(selectorData.getPluginName())).ifPresent(handler -> handler.removeSelector(selectorData));}// 规则的操作} else if (data instanceof RuleData) {RuleData ruleData = (RuleData) data;if (dataType == DataEventTypeEnum.UPDATE) {BaseDataCache.getInstance().cacheRuleData(ruleData);Optional.ofNullable(handlerMap.get(ruleData.getPluginName())).ifPresent(handler -> handler.handlerRule(ruleData));} else if (dataType == DataEventTypeEnum.DELETE) {BaseDataCache.getInstance().removeRuleData(ruleData);Optional.ofNullable(handlerMap.get(ruleData.getPluginName())).ifPresent(handler -> handler.removeRule(ruleData));}}});}
}// 这个类中触发了上面单个插件的配置，并且这个类拿到了所有的插件数据
public class PluginDataHandler extends AbstractDataHandler<PluginData> {@Overrideprotected void doRefresh(final List<PluginData> dataList) {// 触发上面的调用pluginDataSubscriber.refreshPluginDataSelf(dataList);dataList.forEach(pluginDataSubscriber::onSubscribe);}
}// 继续跟下去，看看datalist的来源
public abstract class AbstractDataHandler<T> implements DataHandler {@Overridepublic void handle(final String json, final String eventType) {List<T> dataList = convert(json);if (CollectionUtils.isNotEmpty(dataList)) {DataEventTypeEnum eventTypeEnum = DataEventTypeEnum.acquireByName(eventType);switch (eventTypeEnum) {case REFRESH:case MYSELF:// 触发上面函数的调用doRefresh(dataList);break;case UPDATE:case CREATE:doUpdate(dataList);break;case DELETE:doDelete(dataList);break;default:break;}}}
}// 来到了websocket，进行跟
public class WebsocketDataHandler {public void executor(final ConfigGroupEnum type, final String json, final String eventType) {ENUM_MAP.get(type).handle(json, eventType);}
}// 在这个类中，看到插件数据列表是从websocket来的，那就是从Soul-Admin那边获取来到的数据
public final class SoulWebsocketClient extends WebSocketClient {public void onMessage(final String result) {handleResult(result);}  @SuppressWarnings("ALL")private void handleResult(final String result) {WebsocketData websocketData = GsonUtils.getInstance().fromJson(result, WebsocketData.class);ConfigGroupEnum groupEnum = ConfigGroupEnum.acquireByName(websocketData.getGroupType());String eventType = websocketData.getEventType();String json = GsonUtils.getInstance().toJson(websocketData.getData());websocketDataHandler.executor(groupEnum, json, eventType);}
}

看下result的大致内容：也就是一些简单的配置

{"groupType": "PLUGIN","eventType": "MYSELF","data": [{"id": "1","name": "sign","role": 1,"enabled": false}, {"id": "9","name": "hystrix","role": 0,"enabled": false}]
}

结合路由匹配的关键函数,好像它的作用就是用来判断是否开启和根据name获得选择器

public abstract class AbstractSoulPlugin implements SoulPlugin {@Overridepublic Mono<Void> execute(final ServerWebExchange exchange, final SoulPluginChain chain) {String pluginName = named();final PluginData pluginData = BaseDataCache.getInstance().obtainPluginData(pluginName);// 用于判断是否开启if (pluginData != null && pluginData.getEnabled()) {.......}}
}

插件数据这一块的流程定位下来比较轻松，毕竟前面流程也梳理差不多了

选择器和规则数据的初始化流程，这里就不进行定位了，逻辑和插件数据基本一样，这里就不赘述了

总结

今天分析了插件的初始化和相关配置的初始化

插件的初始化是使用Spring的自动配置加载机制进行实现了，结合使用插件都需要引入哪些start的依赖

插件数据、选择器数据、规则数据的初始化，都是从Websocket（或者同步通信模块）那边过来的，接收到数据以后，进行配置加载到本地

我们还看到一些删除和更新相关的操作，这些属于后面的数据同步分析了，这里先放一放

Soul网关源码分析文章列表

Github

Soul源码阅读（一）概览
Soul源码阅读（二）代码初步运行
Soul源码阅读（三）HTTP请求处理概览
Soul网关源码阅读（四）Dubbo请求概览
Soul网关源码阅读（五）请求类型探索
Soul网关源码阅读（六）Sofa请求处理概览
Soul网关源码阅读（七）限流插件初探
Soul网关源码阅读（八）路由匹配初探
Soul网关源码阅读番外篇（一） HTTP参数请求错误

掘金

Soul网关源码阅读（一）概览
Soul网关源码阅读（二）代码初步运行
Soul网关源码阅读（三）请求处理概览
Soul网关源码阅读（四）Dubbo请求概览
Soul网关源码阅读（五）请求类型探索
Soul网关源码阅读（六）Sofa请求处理概览
Soul网关源码阅读（七）限流插件初探
Soul网关源码阅读（八）路由匹配初探
Soul网关源码阅读番外篇（一） HTTP参数请求错误