Fetch configuration from CBS

- Fix memory leak.
- Add reactive configuration fetching from Consul. Now configuration is updated when any change in VES configuration has been done in Consul.

Change-Id: I9cd42e04844c9e99d4d03951185523b569dc9483
Issue-ID: DCAEGEN2-2495
Signed-off-by: Zebek Bogumil <bogumil.zebek@nokia.com>
(cherry picked from commit 1599617246f0ffec1b1c7840f9c7c42318183dcd)

1 files changed, 95 insertions, 0 deletions

diff --git a/src/main/java/org/onap/dcae/configuration/ConfigUpdater.java b/src/main/java/org/onap/dcae/configuration/ConfigUpdater.java
new file mode 100644
index 00000000..eb1a1a5f
--- /dev/null
+++ b/src/main/java/org/onap/dcae/configuration/ConfigUpdater.java
@@ -0,0 +1,95 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * org.onap.dcaegen2.collectors.ves
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. 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.dcae.configuration;
+
+import io.vavr.collection.Map;
+import io.vavr.control.Option;
+import org.json.JSONObject;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ConfigUpdater {
+
+    private static final Logger log = LoggerFactory.getLogger(ConfigUpdater.class);
+    private final ConfigFilesFacade configFilesFacade;
+    private final Runnable applicationRestarter;
+    private boolean isApplicationRestartNeeded;
+
+    public ConfigUpdater(ConfigFilesFacade configFilesFacade, Runnable applicationRestarter) {
+        this.configFilesFacade = configFilesFacade;
+        this.applicationRestarter = applicationRestarter;
+        this.isApplicationRestartNeeded = false;
+    }
+
+    public synchronized void updateConfig(Option<JSONObject> appConfig) {
+        appConfig.peek(this::handleUpdate).onEmpty(logSkipMessage());
+    }
+
+    private Runnable logSkipMessage() {
+        return () -> log.info("Skipping dynamic configuration");
+    }
+
+    private void handleUpdate(JSONObject appConfig) {
+        updatePropertiesIfChanged(appConfig);
+        updateDmaapConfigIfChanged(appConfig);
+        restartApplicationIfNeeded();
+    }
+
+    private void updatePropertiesIfChanged(JSONObject appConfig) {
+        Map<String, String> newProperties = ConfigParsing.getProperties(appConfig);
+        Map<String, String> oldProperties = configFilesFacade.readCollectorProperties().get();
+
+        if (!areCommonPropertiesSame(oldProperties, newProperties)) {
+            configFilesFacade.writeProperties(newProperties);
+            isApplicationRestartNeeded = true;
+        }
+    }
+
+    private boolean areCommonPropertiesSame(Map<String, String> oldProperties, Map<String, String> newProperties) {
+        Map<String, String> filteredOldProperties = filterIntersectingKeys(oldProperties, newProperties);
+        return filteredOldProperties.equals(newProperties);
+    }
+
+    private Map<String, String> filterIntersectingKeys(Map<String, String> primaryProperties,
+        Map<String, String> otherProperties) {
+        return primaryProperties.filterKeys(key -> containsKey(key, otherProperties));
+    }
+
+    private boolean containsKey(String key, Map<String, String> properties) {
+        return properties.keySet().contains(key);
+    }
+
+    private void updateDmaapConfigIfChanged(JSONObject appConfig) {
+        JSONObject oldDmaapConfig = configFilesFacade.readDMaaPConfiguration().get();
+        JSONObject newDmaapConfig = ConfigParsing.getDMaaPConfig(appConfig).get();
+
+        if (!oldDmaapConfig.similar(newDmaapConfig)) {
+            configFilesFacade.writeDMaaPConfiguration(newDmaapConfig);
+            isApplicationRestartNeeded = true;
+        }
+    }
+
+    private void restartApplicationIfNeeded() {
+        if (isApplicationRestartNeeded) {
+            applicationRestarter.run();
+            isApplicationRestartNeeded = false;
+        }
+    }
+}