Merge pull request #30 from zeebe-io/24-env-variables

chore(exporter): configure JDBC property via environment variables

exporter/README.md

@@ -37,8 +37,8 @@ className = "io.zeebe.monitor.SimpleMonitorExporter"
 
 ### Configure the Exporter
 
-The jdbc uses some default properties which can be configured as well.
-To do this you can add the following. All values are commeted out and have the default values. To change them remove the `#` and change the value.
+The JDBC uses some default properties which can be configured as well.
+To do this you can add the following. All values are commented out and have the default values. To change them remove the `#` and change the value.
 
 ```
 [[exporters]]
@@ -70,6 +70,13 @@ className = "io.zeebe.monitor.SimpleMonitorExporter"
   #batchTimerMilli = 1000
 ```
 
+The JDBC properties can also be set by the following environment variables:
+
+* `SIMPLE_MONITOR_EXPORTER_JDBC_URL`
+* `SIMPLE_MONITOR_EXPORTER_JDBC_DRIVER`
+* `SIMPLE_MONITOR_EXPORTER_JDBC_USER`
+* `SIMPLE_MONITOR_EXPORTER_JDBC_PASSWORD`
+
 ### Start the broker
 
 After configure the broker and also maybe configuring the exporter you are done and can start the broker.

exporter/src/main/java/io/zeebe/monitor/SimpleMonitorExporter.java

@@ -31,6 +31,8 @@
 import io.zeebe.protocol.intent.DeploymentIntent;
 import io.zeebe.protocol.intent.Intent;
 import io.zeebe.protocol.intent.WorkflowInstanceIntent;
+import org.slf4j.Logger;
+
 import java.io.BufferedReader;
 import java.io.InputStream;
 import java.io.InputStreamReader;
@@ -39,17 +41,18 @@
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.time.Duration;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.UUID;
+import java.util.*;
 import java.util.function.Consumer;
 import java.util.stream.Collectors;
-import org.slf4j.Logger;
 
 public class SimpleMonitorExporter implements Exporter {
 
+  private static final String ENV_PREFIX = "SIMPLE_MONITOR_EXPORTER_";
+  private static final String ENV_JDBC_URL = ENV_PREFIX + "JDBC_URL";
+  private static final String ENV_JDBC_DRIVER = ENV_PREFIX + "JDBC_DRIVER";
+  private static final String ENV_JDBC_USER = ENV_PREFIX + "JDBC_USER";
+  private static final String ENV_JDBC_PASSWORD = ENV_PREFIX + "JDBC_PASSWORD";
+
   private static final String INSERT_WORKFLOW =
       "INSERT INTO WORKFLOW (ID_, KEY_, BPMN_PROCESS_ID_, VERSION_, RESOURCE_, TIMESTAMP_) VALUES ('%s', %d, '%s', %d, '%s', %d);";
 
@@ -102,6 +105,9 @@ public void configure(final Context context) {
     log = context.getLogger();
     configuration =
         context.getConfiguration().instantiate(SimpleMonitorExporterConfiguration.class);
+
+    applyEnvironmentVariables(configuration);
+
     batchSize = configuration.batchSize;
     batchTimerMilli = configuration.batchTimerMilli;
 
@@ -113,6 +119,19 @@ public void configure(final Context context) {
     }
   }
 
+  private void applyEnvironmentVariables(final SimpleMonitorExporterConfiguration configuration) {
+    final Map<String, String> environment = System.getenv();
+
+    Optional.ofNullable(environment.get(ENV_JDBC_URL))
+        .ifPresent(url -> configuration.jdbcUrl = url);
+    Optional.ofNullable(environment.get(ENV_JDBC_DRIVER))
+        .ifPresent(driver -> configuration.driverName = driver);
+    Optional.ofNullable(environment.get(ENV_JDBC_USER))
+        .ifPresent(user -> configuration.userName = user);
+    Optional.ofNullable(environment.get(ENV_JDBC_PASSWORD))
+        .ifPresent(password -> configuration.password = password);
+  }
+
   @Override
   public void open(final Controller controller) {
     try {
@@ -121,7 +140,8 @@ public void open(final Controller controller) {
               configuration.jdbcUrl, configuration.userName, configuration.password);
       connection.setAutoCommit(true);
     } catch (final SQLException e) {
-      throw new RuntimeException("Error on opening database.", e);
+      throw new RuntimeException(
+          String.format("Error on opening database with configuration %s.", configuration), e);
     }
 
     createTables();
@@ -201,7 +221,7 @@ private void exportDeploymentRecord(final Record record) {
     final RecordMetadata metadata = record.getMetadata();
     if (metadata.getIntent() != DeploymentIntent.CREATED
         || metadata.getPartitionId() != Protocol.DEPLOYMENT_PARTITION) {
-    	// ignore deployment event on other partitions to avoid duplicates
+      // ignore deployment event on other partitions to avoid duplicates
       return;
     }
     final long timestamp = record.getTimestamp().toEpochMilli();

exporter/src/main/java/io/zeebe/monitor/SimpleMonitorExporterConfiguration.java

@@ -30,4 +30,20 @@ public class SimpleMonitorExporterConfiguration {
    * <p>If the value is less then one, then no timer will be scheduled.
    */
   int batchTimerMilli = 1000;
+
+  @Override
+  public String toString() {
+    return "SimpleMonitorExporterConfiguration{"
+        + "jdbcUrl='"
+        + jdbcUrl
+        + '\''
+        + ", driverName='"
+        + driverName
+        + '\''
+        + ", batchSize="
+        + batchSize
+        + ", batchTimerMilli="
+        + batchTimerMilli
+        + '}';
+  }
 }