Changes for Monitoring and Alerting (health check using dropwizard-metrics)

lightblue-ldap-common/src/main/java/com/redhat/lightblue/common/ldap/DBResolver.java

@@ -18,6 +18,8 @@
  */
 package com.redhat.lightblue.common.ldap;
 
+import java.util.Map;
+
 import com.redhat.lightblue.metadata.DataStore;
 import com.unboundid.ldap.sdk.LDAPConnection;
 import com.unboundid.ldap.sdk.LDAPException;
@@ -36,5 +38,13 @@ public interface DBResolver {
      * to the same database.
      */
     LDAPConnection get(DataStore store) throws LDAPException;
-
+
+
+    /**
+     * @return A {@link Map} of LDAP Database name and corresponding connection
+     *         status as true/false. The status may be an object of
+     *         {@link LDAPException} if no connection is available, or a problem
+     *         occurs while creating a new connection to return
+     */
+    Map<String, Object> getLDAPConnectionsStatus();
 }

lightblue-ldap-config/src/main/java/com/redhat/lightblue/config/ldap/LdapDBResolver.java

@@ -18,6 +18,8 @@
  */
 package com.redhat.lightblue.config.ldap;
 
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Set;
 
 import com.redhat.lightblue.common.ldap.DBResolver;
@@ -68,4 +70,27 @@ private LdapDataSourceConfiguration findByDatabase(String database){
         return null;
     }
 
+    @Override
+    public Map<String, Object> getLDAPConnectionsStatus() {
+
+        Map<String, Object> connectionsStatus = new HashMap<>();
+        LDAPConnection connection = null;
+
+        for (LdapDataSourceConfiguration ldapDS : ldapDataSources) {
+            try {
+                connection = ldapDS.getLdapConnection();
+
+                // If a problem is detected that suggests that the provided
+                // connection is not suitable for use, LDAPException would be
+                // thrown.
+                ldapDS.getLdapConnectionPool().getHealthCheck().ensureConnectionValidForContinuedUse(connection);
+
+                connectionsStatus.put(ldapDS.getDatabaseName(), connection.isConnected());
+            } catch (LDAPException e) {
+                connectionsStatus.put(ldapDS.getDatabaseName(), e);
+            }
+        }
+
+        return connectionsStatus;
+    }
 }

lightblue-ldap-config/src/main/java/com/redhat/lightblue/config/ldap/LdapDataSourceConfiguration.java

@@ -84,6 +84,13 @@ public LDAPConnection getLdapConnection() throws LDAPException{
         }
         return connectionPool.getConnection();
     }
+
+    public LDAPConnectionPool getLdapConnectionPool() throws LDAPException{
+        if(connectionPool == null){
+            throw new IllegalStateException("Class has not yet been initialized");
+        }
+        return connectionPool;
+    }
 
     @Override
     public void initializeFromJson(JsonNode node) {

lightblue-ldap-crud/src/main/java/com/redhat/lightblue/crud/ldap/LdapCRUDController.java

@@ -1,18 +1,14 @@
 /*
  Copyright 2014 Red Hat, Inc. and/or its affiliates.
-
  This file is part of lightblue.
-
  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.
-
  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
-
  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
@@ -43,6 +39,7 @@
 import com.redhat.lightblue.crud.CRUDUpdateResponse;
 import com.redhat.lightblue.crud.CrudConstants;
 import com.redhat.lightblue.crud.DocCtx;
+import com.redhat.lightblue.crud.CRUDHealth;
 import com.redhat.lightblue.crud.ListDocumentStream;
 import com.redhat.lightblue.crud.ldap.translator.EntryTranslatorFromJson;
 import com.redhat.lightblue.crud.ldap.translator.ModificationTranslatorFromJson;
@@ -533,5 +530,26 @@ private abstract class ExecutionHandler {
         abstract void onSuccess(LDAPResult result);
 
     }
+
+    @Override
+    public CRUDHealth checkHealth() {
+        boolean isHealthy = true;
+        Map<String, Object> ldapConnnectionsStatus = dbResolver.getLDAPConnectionsStatus();
+        List<String> details = new ArrayList<>(ldapConnnectionsStatus.size());
+
+        for (Map.Entry<String, Object> connectionStatus : ldapConnnectionsStatus.entrySet()) {
 
+            if (connectionStatus.getValue() instanceof LDAPException) {
+                isHealthy = false;
+                details.add(new StringBuilder("LDAPConnection [DatabaseName: ").append(connectionStatus.getKey())
+                        .append(", Status: ").append(connectionStatus.getValue()).toString());
+            } else {
+                isHealthy = (Boolean) connectionStatus.getValue();
+
+                details.add(new StringBuilder("LDAPConnection [DatabaseName: ").append(connectionStatus.getKey())
+                        .append(", Status: ").append(connectionStatus.getValue()).toString());
+            }
+        }
+        return new CRUDHealth(isHealthy, details.toString());
+    }
 }