feat: addition of datasource plugin handler

README.adoc

@@ -116,3 +116,9 @@ A resource plugin is a generic concept that can be implemented by each product.
 The Gravitee Plugin Service Discovery module allows for loading service discovery plugin by providing a specific plugin handler.
 
 Service discovery plugins are useful to dynamically register or deregister endpoints. There is currently one implementation supporting Consul.
+
+=== Datasources
+
+The Gravitee Plugin Datasource module provides a datasource plugin handler in charge of detecting and loading all the datasource plugins.
+
+Datasource plugins are useful to provide a common connection pool or client to a data storage. There is currently one implementation supporting Redis.

gravitee-plugin-core/src/main/java/io/gravitee/plugin/core/internal/AbstractPluginEventListener.java

@@ -21,7 +21,14 @@
 import io.gravitee.plugin.core.api.Plugin;
 import io.gravitee.plugin.core.api.PluginEvent;
 import io.gravitee.plugin.core.api.PluginHandler;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import lombok.AccessLevel;
 import lombok.Getter;
@@ -40,10 +47,24 @@ public abstract class AbstractPluginEventListener
     implements EventListener<PluginEvent, Plugin> {
 
     public static final String SECRET_PROVIDER = "secret-provider";
+    public static final String DATASOURCE = "datasource";
+    public static final String CLUSTER = "cluster";
+    public static final String CACHE = "cache";
+    public static final String REPOSITORY = "repository";
+    public static final String ALERT = "alert";
+    public static final String COCKPIT = "cockpit";
     /**
      * Allows to define priority between the different plugin types.
      */
-    private static final List<String> pluginPriority = Arrays.asList(SECRET_PROVIDER, "cluster", "cache", "repository", "alert", "cockpit");
+    private static final List<String> pluginPriority = Arrays.asList(
+        SECRET_PROVIDER,
+        CLUSTER,
+        DATASOURCE,
+        CACHE,
+        REPOSITORY,
+        ALERT,
+        COCKPIT
+    );
 
     private final Collection<PluginHandler> pluginHandlers;
 

gravitee-plugin-datasource/pom.xml

@@ -0,0 +1,49 @@
+<!--
+
+    Copyright © 2015 The Gravitee team (http://gravitee.io)
+
+    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.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>io.gravitee.plugin</groupId>
+        <artifactId>gravitee-plugin</artifactId>
+        <version>4.1.0</version>
+    </parent>
+
+    <artifactId>gravitee-plugin-datasource</artifactId>
+    <packaging>jar</packaging>
+
+    <name>Gravitee.io - Plugin - Datasource</name>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.gravitee.datasource</groupId>
+            <artifactId>gravitee-datasource-api</artifactId>
+            <version>${gravitee-datasource-api.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>io.gravitee.plugin</groupId>
+            <artifactId>gravitee-plugin-core</artifactId>
+        </dependency>
+
+    </dependencies>
+</project>

gravitee-plugin-datasource/src/main/java/io/gravitee/plugin/datasource/DatasourcePlugin.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright © 2015 The Gravitee team (http://gravitee.io)
+ *
+ * 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.gravitee.plugin.datasource;
+
+import io.gravitee.datasource.api.Datasource;
+import io.gravitee.datasource.api.DatasourceConfiguration;
+import io.gravitee.datasource.api.DatasourceConfigurationMapper;
+import io.gravitee.plugin.core.api.ConfigurablePlugin;
+import io.gravitee.plugin.core.api.Plugin;
+
+public interface DatasourcePlugin<C extends DatasourceConfiguration, CM extends DatasourceConfigurationMapper>
+    extends ConfigurablePlugin<C> {
+    String PLUGIN_TYPE = "datasource";
+
+    Plugin pluginDefinition();
+
+    Class<? extends Datasource> datasource();
+
+    Class<CM> configurationMapper();
+
+    @Override
+    default String type() {
+        return PLUGIN_TYPE;
+    }
+}

gravitee-plugin-datasource/src/main/java/io/gravitee/plugin/datasource/DatasourcePluginHandler.java

@@ -0,0 +1,135 @@
+/*
+ * Copyright © 2015 The Gravitee team (http://gravitee.io)
+ *
+ * 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.gravitee.plugin.datasource;
+
+import static org.springframework.util.StringUtils.hasText;
+
+import io.gravitee.datasource.api.Datasource;
+import io.gravitee.datasource.api.DatasourceConfiguration;
+import io.gravitee.plugin.core.api.AbstractPluginHandler;
+import io.gravitee.plugin.core.api.Plugin;
+import io.gravitee.plugin.core.api.PluginContextFactory;
+import io.gravitee.plugin.datasource.internal.DatasourceConfigurationClassFinder;
+import io.gravitee.plugin.datasource.internal.DatasourceConfigurationFactory;
+import io.gravitee.plugin.datasource.internal.DatasourceConfigurationMapperClassFinder;
+import io.gravitee.plugin.datasource.spring.DatasourcePluginConfiguration;
+import java.net.URLClassLoader;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Import;
+import org.springframework.core.env.Environment;
+
+/**
+ * @author Eric LELEU (eric.leleu at graviteesource.com)
+ * @author GraviteeSource Team
+ */
+@Import(DatasourcePluginConfiguration.class)
+public class DatasourcePluginHandler extends AbstractPluginHandler {
+
+    private static final String CONF_DATASOURCES = "datasources";
+    public static final String DATASOURCE_ID = "id";
+    public static final String DATASOURCE_ENABLED = "enabled";
+    public static final String DATASOURCE_SETTINGS = "settings";
+
+    @Autowired
+    private DatasourcePluginManager datasourcePluginManager;
+
+    @Autowired
+    private Environment environment;
+
+    @Autowired
+    private PluginContextFactory pluginContextFactory;
+
+    @Autowired
+    private DatasourceConfigurationFactory configurationFactory;
+
+    @Override
+    protected String type() {
+        return DatasourcePlugin.PLUGIN_TYPE;
+    }
+
+    @Override
+    protected ClassLoader getClassLoader(Plugin plugin) throws Exception {
+        return new URLClassLoader(plugin.dependencies(), this.getClass().getClassLoader());
+    }
+
+    @Override
+    protected void handle(Plugin plugin, Class<?> pluginClass) {
+        // register plugin definition to make DS available
+        // through UI not only through gravitee.yaml
+        DatasourcePlugin datasourcePlugin = create(plugin, pluginClass);
+        register(datasourcePlugin);
+
+        // instantiate plugin form gravitee.yaml
+        if (plugin.deployed()) {
+            var pluginIndex = 0;
+            while (environment.containsProperty(datasourceConfigEntries(plugin, pluginIndex, DATASOURCE_ID))) {
+                instantiate(datasourcePlugin, pluginIndex++);
+            }
+        }
+    }
+
+    private void instantiate(DatasourcePlugin datasourcePlugin, int pluginIndex) {
+        final var plugin = datasourcePlugin.pluginDefinition();
+        if (environment.getProperty(datasourceConfigEntries(plugin, pluginIndex, DATASOURCE_ENABLED), boolean.class, true)) {
+            final var instanceName = environment.getProperty(datasourceConfigEntries(plugin, pluginIndex, DATASOURCE_ID), String.class);
+            if (!hasText(instanceName)) {
+                logger.warn("name is missing for datasource plugin {}, skip the instance creation", plugin.id());
+                return;
+            }
+
+            logger.info("Loading datasource plugin {} with name {}", plugin.id(), instanceName);
+            try {
+                DatasourceConfiguration configuration = configurationFactory.build(
+                    datasourcePlugin.configurationMapper(),
+                    datasourceConfigEntries(plugin, pluginIndex, DATASOURCE_SETTINGS)
+                );
+                final var ds = createInstance(datasourcePlugin, configuration);
+                ds.start();
+
+                this.datasourcePluginManager.addDatasource(plugin, instanceName, ds);
+            } catch (Exception e) {
+                logger.error("Unable to instantiate datasource plugin of type {}", plugin.type(), e);
+            }
+        }
+    }
+
+    private static String datasourceConfigEntries(Plugin plugin, int pluginIndex, String key) {
+        return CONF_DATASOURCES + "." + plugin.id() + "[" + pluginIndex + "]." + key;
+    }
+
+    public Datasource createInstance(DatasourcePlugin datasourcePlugin, DatasourceConfiguration config) {
+        var pluginContext = pluginContextFactory.create(datasourcePlugin);
+        var ds = (Datasource) pluginContext.getAutowireCapableBeanFactory().createBean(datasourcePlugin.datasource());
+        ds.setConfiguration(config);
+        return ds;
+    }
+
+    protected DatasourcePlugin create(Plugin plugin, Class<?> pluginClass) {
+        DatasourcePluginImpl resourcePlugin = new DatasourcePluginImpl(plugin, pluginClass);
+        resourcePlugin.setConfiguration(new DatasourceConfigurationClassFinder().lookupFirst(pluginClass));
+        resourcePlugin.setConfigurationMapper(new DatasourceConfigurationMapperClassFinder().lookupFirst(pluginClass));
+        return resourcePlugin;
+    }
+
+    protected void register(DatasourcePlugin plugin) {
+        datasourcePluginManager.register(plugin);
+    }
+
+    @Override
+    public boolean canHandle(Plugin plugin) {
+        return type().equalsIgnoreCase(plugin.type());
+    }
+}

gravitee-plugin-datasource/src/main/java/io/gravitee/plugin/datasource/DatasourcePluginImpl.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright © 2015 The Gravitee team (http://gravitee.io)
+ *
+ * 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.gravitee.plugin.datasource;
+
+import io.gravitee.datasource.api.DatasourceConfiguration;
+import io.gravitee.datasource.api.DatasourceConfigurationMapper;
+import io.gravitee.plugin.core.api.Plugin;
+import io.gravitee.plugin.core.api.PluginManifest;
+import java.net.URL;
+import java.nio.file.Path;
+
+/**
+ * @author Eric LELEU (eric.leleu at graviteesource.com)
+ * @author GraviteeSource Team
+ */
+public class DatasourcePluginImpl implements DatasourcePlugin {
+
+    private final Plugin plugin;
+    private final Class<?> datasourceClass;
+    private Class<? extends DatasourceConfiguration> configuration;
+    private Class<? extends DatasourceConfigurationMapper> configurationMapper;
+
+    public DatasourcePluginImpl(final Plugin plugin, final Class<?> datasourceClass) {
+        this.plugin = plugin;
+        this.datasourceClass = datasourceClass;
+    }
+
+    @Override
+    public Class<?> datasource() {
+        return datasourceClass;
+    }
+
+    @Override
+    public Plugin pluginDefinition() {
+        return plugin;
+    }
+
+    @Override
+    public String clazz() {
+        return plugin.clazz();
+    }
+
+    @Override
+    public URL[] dependencies() {
+        return plugin.dependencies();
+    }
+
+    @Override
+    public String id() {
+        return plugin.id();
+    }
+
+    @Override
+    public PluginManifest manifest() {
+        return plugin.manifest();
+    }
+
+    @Override
+    public Path path() {
+        return plugin.path();
+    }
+
+    @Override
+    public boolean deployed() {
+        return plugin.deployed();
+    }
+
+    @Override
+    public Class configuration() {
+        return configuration;
+    }
+
+    public void setConfiguration(Class<? extends DatasourceConfiguration> datasourceConfigurationClass) {
+        this.configuration = datasourceConfigurationClass;
+    }
+
+    @Override
+    public Class configurationMapper() {
+        return configurationMapper;
+    }
+
+    public void setConfigurationMapper(Class<? extends DatasourceConfigurationMapper> datasourceConfigurationMapperClass) {
+        this.configurationMapper = datasourceConfigurationMapperClass;
+    }
+}