dcdbpusher: New PluginManager class to bundle all plugin related operations....

dcdbpusher: New PluginManager class to bundle all plugin related operations. Integration outstanding

dcdbpusher/Makefile

@@ -27,6 +27,7 @@ OBJS = dcdbpusher.o \
        Configuration.o \
        MQTTPusher.o \
        RestAPI.o \
+       PluginManager.o \
        ../analytics/AnalyticsManager.o \
        ../common/src/sensornavigator.o \
        ../common/src/globalconfiguration.o \

dcdbpusher/PluginManager.cpp

+/*
+ * PluginManager.cpp
+ *
+ *  Created on: 28.05.2019
+ *      Author: Micha Mueller
+ */
+
+#include "PluginManager.h"
+
+#include <dlfcn.h>
+
+#include "mqttchecker.h"
+
+using namespace std;
+
+PluginManager::~PluginManager() {
+    unloadPlugin();
+}
+
+bool PluginManager::loadPlugin(const pluginSettings_t& pluginSettings,
+                               const string& name,
+                               const string& pluginPath,
+                               const string& config) {
+
+    LOG(info) << "Loading plugin " << name << "...";
+    string pluginLib; //path to the plugin-lib
+    string pluginConfig; //path to config file for plugin
+
+    // build plugin path
+    pluginLib = "libdcdbplugin_" + name; //TODO add version information?
+#if __APPLE__
+    pluginLib+= ".dylib";
+#else
+    pluginLib+= ".so";
+#endif
+    if (pluginPath != "") {
+        if (pluginPath[pluginPath.length()-1] != '/') {
+            pluginLib = "/" + pluginLib;
+        }
+        pluginLib = pluginPath + pluginLib;
+    }
+
+    // build plugin config path
+    if (config == "") {
+        pluginConfig = "./" + name + ".conf";
+    } else {
+        pluginConfig = config;
+    }
+
+    //open plugin
+    //dl-code based on http://tldp.org/HOWTO/C++-dlopen/thesolution.html
+
+    //TODO switch to C++17 std::filesystem::exists
+    //check if config file exists
+    FILE *file = NULL;
+    if (!(file = fopen(pluginConfig.c_str(), "r"))) {
+        LOG(warning) << pluginConfig << " not found. Omitting";
+        return false;
+    }
+    fclose(file);
+
+    pusherPlugin_t plugin;
+    plugin.id = name;
+    plugin.DL = NULL;
+    plugin.configurator = NULL;
+
+    //plugin.conf exists --> open libdcdbplugin_NAME.so and read config
+    LOG(info) << pluginConfig << " found";
+    plugin.DL = dlopen(pluginLib.c_str(), RTLD_NOW);
+    if(!plugin.DL) {
+        LOG(error) << "Cannot load " << plugin.id << "-library: " << dlerror();
+        return false;
+    }
+    //reset errors
+    dlerror();
+
+    //set dynLib-struct
+    plugin.create = (create_t*) dlsym(plugin.DL, "create");
+    const char* dlsym_error = dlerror();
+    if (dlsym_error) {
+        LOG(error) << "Cannot load symbol create for " << plugin.id << ": " << dlsym_error;
+        return false;
+    }
+
+    plugin.destroy = (destroy_t*) dlsym(plugin.DL, "destroy");
+    dlsym_error = dlerror();
+    if (dlsym_error) {
+        LOG(error) << "Cannot load symbol destroy for " << plugin.id << ": " << dlsym_error;
+        return false;
+    }
+
+    plugin.configurator = plugin.create();
+    //set prefix to global prefix (may be overwritten)
+    plugin.configurator->setGlobalSettings(pluginSettings);
+    //read in config
+    if (!(plugin.configurator->readConfig(pluginConfig))) {
+        LOG(error) << "Plugin " << plugin.id << " could not read configuration!";
+        return false;
+    }
+
+    // returning an empty vector may indicate problems with the config file
+    if(plugin.configurator->getSensorGroups().size() == 0) {
+        LOG(warning) << "Plugin " << plugin.id << " created no sensors!";
+    }
+
+    //check if an MQTT-suffix was assigned twice
+    if (!checkTopics(plugin)) {
+        LOG(error) << "Problematic MQTT topics or sensor names, please check your config files!";
+        removeTopics(plugin);
+        return false;
+    }
+
+    //save dl-struct
+    _plugins.push_back(plugin);
+    LOG(info) << "Plugin " << plugin.id << " " << plugin.configurator->getVersion() << " loaded!";
+
+    return true;
+}
+
+void PluginManager::unloadPlugin(const string& id) {
+    for (auto it = _plugins.begin(); it != _plugins.end(); ++it) {
+        if (it->id == id || id == "") {
+            for (const auto& g : it->configurator->getSensorGroups()) {
+                g->stop();
+            }
+
+            if (it->configurator) {
+                it->destroy(it->configurator);
+            }
+            if (it->DL) {
+                dlclose(it->DL);
+            }
+            _plugins.erase(it);
+        }
+    }
+}
+
+bool PluginManager::initPlugin(boost::asio::io_service io,
+                               const string& id) {
+    bool found = false;
+
+    for (const auto& p : _plugins) {
+        if (p.id == id || id == "") {
+            for (const auto& g : p.configurator->getSensorGroups()) {
+                found = true;
+                g->init(io);
+            }
+        }
+    }
+
+    if (!found) {
+        LOG(warning) << "Could not find plugin " << id << " to initialize!";
+    } else {
+        LOG(info) << "Initialized plugin " << id;
+    }
+    return found;
+}
+
+bool PluginManager::startPlugin(const string& id) {
+    bool found = false;
+
+    for (const auto& p : _plugins) {
+        if (p.id == id || id == "") {
+            for (const auto& g : p.configurator->getSensorGroups()) {
+                found = true;
+                g->start();
+            }
+        }
+    }
+
+    if (!found) {
+        LOG(warning) << "Could not find plugin " << id << " to start!";
+    } else {
+        LOG(info) << "Started plugin " << id;
+    }
+    return found;
+}
+
+bool PluginManager::stopPlugin(const string& id) {
+    bool found = false;
+
+    for (const auto& p : _plugins) {
+        if (p.id == id || id == "") {
+            for (const auto& g : p.configurator->getSensorGroups()) {
+                found = true;
+                g->stop();
+            }
+        }
+    }
+
+    if (!found) {
+        LOG(warning) << "Could not find plugin " << id << " to stop!";
+    } else {
+        LOG(info) << "Stopped plugin " << id;
+    }
+    return found;
+}
+
+bool PluginManager::reloadPluginConfig(const string& id) {
+    for (const auto& p : _plugins) {
+        if (p.id == id) {
+            // Removing obsolete MQTT topics
+            removeTopics(p);
+            if (p.configurator->reReadConfig()) {
+                // Perform checks on MQTT topics
+                if(!checkTopics(p)) {
+                    LOG(warning) << "Plugin " + id + ": problematic MQTT topics or sensor names, please check your config files!";
+                    removeTopics(p);
+                    p.configurator->clearConfig();
+                    return false;
+                } else {
+                    LOG(info) << "Plugin " + id + ": Configuration reloaded.";
+                    return true;
+                }
+            } else {
+                LOG(warning) << "Plugin " << id << ": Could not reload configuration!";
+                return false;
+            }
+        }
+    }
+    return false;
+}
+
+bool PluginManager::checkTopics(const pusherPlugin_t& p) {
+    MQTTChecker& mqttCheck = MQTTChecker::getInstance();
+    bool validTopics=true;
+
+    for(const auto& g : p.configurator->getSensorGroups()) {
+        if (!mqttCheck.checkGroup(g->getGroupName())) {
+            validTopics = false;
+        }
+        for (const auto& s : g->getSensors()) {
+            if (!mqttCheck.checkTopic(s->getMqtt()) || !mqttCheck.checkName(s->getName())) {
+                validTopics = false;
+            }
+        }
+    }
+
+    return validTopics;
+}
+
+void PluginManager::removeTopics(const pusherPlugin_t& p) {
+    MQTTChecker& mqttCheck = MQTTChecker::getInstance();
+    for(const auto& g : p.configurator->getSensorGroups()) {
+        mqttCheck.removeGroup(g->getGroupName());
+        for (const auto &s : g->getSensors()) {
+            mqttCheck.removeTopic(s->getMqtt());
+            mqttCheck.removeName(s->getName());
+        }
+    }
+}

dcdbpusher/PluginManager.h

+/*
+ * PluginManager.h
+ *
+ *  Created on: 27.05.2019
+ *      Author: Micha Mueller
+ */
+
+#ifndef DCDBPUSHER_PLUGINMANAGER_H_
+#define DCDBPUSHER_PLUGINMANAGER_H_
+
+#include <string>
+#include <vector>
+#include <boost/asio.hpp>
+
+#include "logging.h"
+
+#include "includes/ConfiguratorInterface.h"
+
+/*
+ * Bundles all attributes to hold a dcdb-pusher plugin aka dynamic library.
+ */
+typedef struct {
+    std::string id;
+    void*   DL;
+    ConfiguratorInterface* configurator;
+    create_t*  create;
+    destroy_t* destroy;
+} pusherPlugin_t;
+
+using pusherPluginStorage_t = std::vector<pusherPlugin_t>;
+
+/**
+ * @brief This class is responsible of managing plugins for dcdbpusher.
+ *
+ */
+class PluginManager {
+
+public:
+    PluginManager() {};
+
+    virtual ~PluginManager();
+
+    /**
+     * @brief Load a new plugin.
+     *
+     * @details Searches and loads a shared library file for the plugin as well
+     *          as its corresponding configuration file. The library file name
+     *          is constructed from the plugin name according to
+     *          libdcdbplugin_NAME.so (or .dylib for Apple). After the shared
+     *          library is loaded the plugin reads in its configuration. After
+     *          loading the plugin still has to be initialized (initPlugin())
+     *          before it can be started (startPlugin()).
+     *
+     *
+     * @param pluginSettings Default settings for the plugin.
+     * @param name           Identifying name (ID) of the new plugin.
+     * @param pluginPath     Path where the plugin shared library is located. If
+     *                       not specified we will search the default library
+     *                       directories (usr/lib and friends).
+     * @param config         Path to plugin configuration file (including config
+     *                       file name). If not specified we will search in the
+     *                       current directory for "NAME.conf".
+     *
+     * @return True on success, false otherwise. In the latter case the plugin
+     *         is not loaded.
+     */
+    bool loadPlugin(const pluginSettings_t& pluginSettings,
+                    const std::string& name,
+                    const std::string& pluginPath = "",
+                    const std::string& config = "");
+
+    // Undocumented: if no plugin name is specified all plugins are unloaded.
+    /**
+     * @brief Unload a plugin.
+     *
+     * @details Stops the specified plugin and removes it completely from the
+     *          manager. To use the plugin again it has to be loaded first.
+     *
+     * @param id Identifying name of the plugin.
+     */
+    void unloadPlugin(const std::string& id = "");
+
+    // Undocumented: if no plugin name is specified all plugins are initialized.
+    /**
+     * @brief Initialize a plugin.
+     *
+     * @details Initializes a plugin so it can be started. A plugin has to be
+     *          be initialized only once after it was (re)loaded.
+     *
+     * @param io IO service to initialize the plugin's groups with.
+     * @param id Identifying name of the plugin.
+     *
+     * @return True on success, false if the plugin could not be found.
+     */
+    bool initPlugin(boost::asio::io_service io,
+                    const std::string& id = "");
+
+    // Undocumented: if no plugin name is specified all plugins are started.
+    /**
+     * @brief Start a plugin.
+     *
+     * @details Start execution of a previously initialized plugin or resume
+     *          execution of a stopped plugin. An unitialized plugin must not be
+     *          started!
+     *
+     * @param id Identifying name of the plugin.
+     *
+     * @return True on success, false if the plugin could not be found.
+     */
+    bool startPlugin(const std::string& id = "");
+
+    // Undocumented: if no plugin name is specified all plugins are stopped.
+    /**
+     * @brief Stop a plugin.
+     *
+     * @details Halts execution of the plugin. Can be continued with start().
+     *
+     * @param id Identifying name of the plugin.
+     *
+     * @return True on success, false if the plugin could not be found.
+     */
+    bool stopPlugin(const std::string& id = "");
+
+    /**
+     * @brief Reload the plugin's configuration.
+     *
+     * @details Clears the plugin internal configuration (deleting all of its
+     *          groups and sensors). Reads in the plugin configuration again.
+     *          At the end the plugin is in the same state as after it was
+     *          loaded (i.e. it is not initialized yet). The plugin
+     *          configuration file is expected to be the same (name and
+     *          location) as when the plugin was first loaded.
+     *
+     * @param id Identifying name of the plugin.
+     *
+     * @return True on success, false otherwise. In the latter case the plugin
+     *         is in an undefined state and should not be started. Failure is
+     *         most likely caused by an invalid new configuration file. Try to
+     *         reload the plugin again with a valid configuration.
+     */
+    bool reloadPluginConfig(const std::string& id);
+
+    /**
+     * @brief Get all currently loaded plugins.
+     *
+     * @return Storage of currently loaded plugins.
+     */
+    pusherPluginStorage_t& getPlugins() {
+        return _plugins;
+    }
+
+private:
+
+    /**
+     * @brief Utility method to check if the MQTT topics of the given plugin are
+     *        valid.
+     *
+     * @param p Plugin.
+     *
+     * @return True if all topics are valid, false otherwise.
+     */
+    bool checkTopics(const pusherPlugin_t& p);
+
+    /**
+     * @brief Utility method to remove all MQTT topics associated to a plugin
+     *        from the used set.
+     *
+     * @param p Plugin.
+     */
+    void removeTopics(const pusherPlugin_t& p);
+
+    pusherPluginStorage_t _plugins; /**< Storage to hold all loaded plugins */
+    logger_t lg;
+};
+
+
+
+#endif /* DCDBPUSHER_PLUGINMANAGER_H_ */