Move GraphChecker to aai-common

- define GraphCheck class that tests connection to storage backend
- disable caching for the db transaction to make sure that the real connection is tested
- define GraphConfig class that defines a Graph bean. This is an alternative to the AAIGraph class

Issue-ID: AAI-4060
Change-Id: Id6d20adc8a8bab8bc914fb47353c37fd80905896
Signed-off-by: Fiete Ostkamp <Fiete.Ostkamp@telekom.de>

3 files changed, 201 insertions, 0 deletions

diff --git a/aai-core/src/main/java/org/onap/aai/config/GraphConfig.java b/aai-core/src/main/java/org/onap/aai/config/GraphConfig.java
new file mode 100644
index 00000000..352821f5
--- /dev/null
+++ b/aai-core/src/main/java/org/onap/aai/config/GraphConfig.java
@@ -0,0 +1,106 @@
+/**
+ * ============LICENSE_START=======================================================
+ * org.onap.aai
+ * ================================================================================
+ * Copyright © 2024 Deutsche Telekom. All rights reserved.
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.aai.config;
+
+import java.io.FileNotFoundException;
+
+import javax.annotation.PreDestroy;
+
+import org.apache.commons.configuration2.ex.ConfigurationException;
+import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource;
+import org.apache.tinkerpop.gremlin.structure.Graph;
+import org.janusgraph.core.JanusGraph;
+import org.janusgraph.core.JanusGraphFactory;
+import org.janusgraph.core.schema.JanusGraphManagement;
+import org.onap.aai.dbgen.SchemaGenerator;
+import org.onap.aai.dbgen.SchemaGenerator4Hist;
+import org.onap.aai.dbmap.AAIGraphConfig;
+import org.onap.aai.exceptions.AAIException;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@Configuration
+public class GraphConfig {
+
+  private static final String IN_MEMORY = "inmemory";
+
+  @Value("${spring.application.name}")
+  private String serviceName;
+
+  @Value("${aai.graph.properties.path}")
+  private String configPath;
+
+  @Bean
+  public org.apache.commons.configuration2.Configuration getGraphProperties()
+      throws FileNotFoundException, ConfigurationException {
+
+    return new AAIGraphConfig.Builder(configPath)
+      .forService(serviceName)
+      .withGraphType("realtime")
+      .buildConfiguration();
+  }
+
+  @Bean
+  public JanusGraph janusGraph(org.apache.commons.configuration2.Configuration graphConfiguration) throws AAIException {
+    JanusGraph graph = JanusGraphFactory.open(graphConfiguration);
+
+    boolean loadSchema = false;
+    if (loadSchema) {
+      if (IN_MEMORY.equals(graphConfiguration.getProperty("storage.backend"))) {
+        // Load the propertyKeys, indexes and edge-Labels into the DB
+        loadSchema(graph);
+      }
+    }
+
+    if (graph == null) {
+      throw new AAIException("AAI_5102");
+    }
+
+    return graph;
+  }
+
+  @Bean
+  public Graph graph(JanusGraph janusGraph) {
+    return janusGraph;
+  }
+
+  @Bean
+  public GraphTraversalSource graphTraversalSource(Graph graph) {
+    return graph.traversal();
+  }
+
+  private void loadSchema(JanusGraph graph) {
+    // Load the propertyKeys, indexes and edge-Labels into the DB
+    boolean dbNotEmpty = graph.traversal().V().limit(1).hasNext();
+    log.info("-- loading schema into JanusGraph");
+    if ("true".equals(
+        SpringContextAware.getApplicationContext().getEnvironment().getProperty("history.enabled", "false"))) {
+      JanusGraphManagement graphMgt = graph.openManagement();
+      SchemaGenerator4Hist.loadSchemaIntoJanusGraph(graphMgt, IN_MEMORY);
+    } else {
+      SchemaGenerator.loadSchemaIntoJanusGraph(graph, IN_MEMORY, dbNotEmpty);
+    }
+  }
+}
diff --git a/aai-core/src/main/java/org/onap/aai/util/GraphChecker.java b/aai-core/src/main/java/org/onap/aai/util/GraphChecker.java
new file mode 100644
index 00000000..43caebc5
--- /dev/null
+++ b/aai-core/src/main/java/org/onap/aai/util/GraphChecker.java
@@ -0,0 +1,93 @@
+/*
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2022 Bell Canada
+ * Modification Copyright (C) 2024 Deutsche Telekom SA
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.aai.util;
+
+import org.janusgraph.core.JanusGraph;
+import org.janusgraph.core.JanusGraphException;
+import org.janusgraph.core.JanusGraphTransaction;
+import org.onap.aai.logging.ErrorLogHelper;
+import org.springframework.stereotype.Component;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class GraphChecker {
+
+    private final JanusGraph graph;
+
+    /**
+     * Checks whether a connection to the graph database can be made.
+     *
+     * @return
+     *         <li>true, if database is available</li>
+     *         <li>false, if database is NOT available</li>
+     */
+    public boolean isAaiGraphDbAvailable() {
+        boolean dbAvailable;
+        JanusGraphTransaction transaction = null;
+        try {
+            // disable caching and other features that are not needed for this check
+            transaction = graph
+                .buildTransaction()
+                .readOnly()
+                .consistencyChecks(false)
+                .vertexCacheSize(0)
+                .skipDBCacheRead()
+                .start();
+            dbAvailable = transaction.traversal().V().limit(1).hasNext();
+        } catch (JanusGraphException e) {
+            String message = "Database is not available (after JanusGraph exception)";
+            ErrorLogHelper.logError("500", message + ": " + e.getMessage());
+            log.error(message, e);
+            dbAvailable = false;
+        } catch (Error e) {
+            // Following error occurs when aai resources is starting:
+            // - UnsatisfiedLinkError (for org.onap.aai.dbmap.AAIGraph$Helper instantiation)
+            // Following errors are raised when aai resources is starting and cassandra is not
+            // running:
+            // - ExceptionInInitializerError
+            // - NoClassDefFoundError (definition for org.onap.aai.dbmap.AAIGraph$Helper is not
+            // found)
+            String message = "Database is not available (after error)";
+            ErrorLogHelper.logError("500", message + ": " + e.getMessage());
+            log.error(message, e);
+            dbAvailable = false;
+        } catch (Exception e) {
+            String message = "Database availability can not be determined";
+            ErrorLogHelper.logError("500", message + ": " + e.getMessage());
+            log.error(message, e);
+            dbAvailable = false;
+        } finally {
+            if (transaction != null && !transaction.isClosed()) {
+                // check if transaction is open then closed instead of flag
+                try {
+                    transaction.rollback();
+                } catch (Exception e) {
+                    String message = "Exception occurred while closing transaction";
+                    log.error(message, e);
+                    ErrorLogHelper.logError("500", message + ": " + e.getMessage());
+                }
+            }
+        }
+        return dbAvailable;
+    }
+}
diff --git a/aai-core/src/main/resources/application.properties b/aai-core/src/main/resources/application.properties
new file mode 100644
index 00000000..ec085cc5
--- /dev/null
+++ b/aai-core/src/main/resources/application.properties
@@ -0,0 +1,2 @@
+spring.application.name=aai-core
+aai.graph.properties.path=src/main/resources/janusgraph-realtime.properties