Codeless EventDataConsumer ctor (#32)

* remove code from EventDataConsumer ctor, separate reporters to Report interface, separate getRealHostname into Hostname object

* add http metrics integration test with syslogBridge

* removed DummyReport usages as it was not really needed.

src/main/java/com/teragrep/aer_02/EventDataConsumer.java

@@ -47,27 +47,19 @@
 
 import com.codahale.metrics.Gauge;
 import com.codahale.metrics.MetricRegistry;
-import com.codahale.metrics.Slf4jReporter;
-import com.codahale.metrics.jmx.JmxReporter;
 import com.teragrep.aer_02.config.RelpConfig;
 import com.teragrep.aer_02.config.SyslogConfig;
 import com.teragrep.aer_02.config.source.Sourceable;
 import com.teragrep.rlo_14.Facility;
 import com.teragrep.rlo_14.SDElement;
 import com.teragrep.rlo_14.Severity;
 import com.teragrep.rlo_14.SyslogMessage;
-import io.prometheus.client.CollectorRegistry;
-import io.prometheus.client.dropwizard.DropwizardExports;
-import org.slf4j.LoggerFactory;
 
-import java.net.InetAddress;
-import java.net.UnknownHostException;
 import java.nio.charset.StandardCharsets;
 import java.time.Instant;
 import java.time.ZonedDateTime;
 import java.util.Map;
 import java.util.UUID;
-import java.util.concurrent.TimeUnit;
 
 import static com.codahale.metrics.MetricRegistry.name;
 
@@ -78,54 +70,26 @@ final class EventDataConsumer implements AutoCloseable {
     private final String realHostName;
     private final SyslogConfig syslogConfig;
     private final MetricRegistry metricRegistry;
-    private final JmxReporter jmxReporter;
-    private final Slf4jReporter slf4jReporter;
 
-    EventDataConsumer(Sourceable configSource) {
-        this(configSource, new MetricRegistry());
-    }
-
-    EventDataConsumer(Sourceable configSource, MetricRegistry metricRegistry) {
+    EventDataConsumer(final Sourceable configSource, final String hostname, final MetricRegistry metricRegistry) {
         this(
                 configSource,
                 new DefaultOutput("defaultOutput", new RelpConfig(configSource), metricRegistry),
+                hostname,
                 metricRegistry
         );
     }
 
-    EventDataConsumer(Sourceable configSource, Output output, MetricRegistry metricRegistry) {
+    EventDataConsumer(
+            final Sourceable configSource,
+            final Output output,
+            final String hostname,
+            final MetricRegistry metricRegistry
+    ) {
         this.metricRegistry = metricRegistry;
         this.output = output;
-        this.realHostName = getRealHostName();
+        this.realHostName = hostname;
         this.syslogConfig = new SyslogConfig(configSource);
-
-        this.jmxReporter = JmxReporter.forRegistry(metricRegistry).build();
-        this.slf4jReporter = Slf4jReporter
-                .forRegistry(metricRegistry)
-                .outputTo(LoggerFactory.getLogger(EventDataConsumer.class))
-                .convertRatesTo(TimeUnit.SECONDS)
-                .convertDurationsTo(TimeUnit.MILLISECONDS)
-                .build();
-        startMetrics();
-    }
-
-    private String getRealHostName() {
-        String hostname;
-        try {
-            hostname = InetAddress.getLocalHost().getHostName();
-        }
-        catch (UnknownHostException e) {
-            hostname = "localhost";
-        }
-        return hostname;
-    }
-
-    private void startMetrics() {
-        this.jmxReporter.start();
-        this.slf4jReporter.start(1, TimeUnit.MINUTES);
-
-        // prometheus-exporter
-        CollectorRegistry.defaultRegistry.register(new DropwizardExports(metricRegistry));
     }
 
     public void accept(
@@ -198,7 +162,5 @@ public Long getValue() {
     @Override
     public void close() throws Exception {
         output.close();
-        slf4jReporter.close();
-        jmxReporter.close();
     }
 }

src/main/java/com/teragrep/aer_02/Hostname.java

@@ -0,0 +1,92 @@
+/*
+ * Teragrep Eventhub Reader as an Azure Function
+ * Copyright (C) 2024 Suomen Kanuuna Oy
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://github.com/teragrep/teragrep/blob/main/LICENSE>.
+ *
+ *
+ * Additional permission under GNU Affero General Public License version 3
+ * section 7
+ *
+ * If you modify this Program, or any covered work, by linking or combining it
+ * with other code, such other code is not for that reason alone subject to any
+ * of the requirements of the GNU Affero GPL version 3 as long as this Program
+ * is the same Program as licensed from Suomen Kanuuna Oy without any additional
+ * modifications.
+ *
+ * Supplemented terms under GNU Affero General Public License version 3
+ * section 7
+ *
+ * Origin of the software must be attributed to Suomen Kanuuna Oy. Any modified
+ * versions must be marked as "Modified version of" The Program.
+ *
+ * Names of the licensors and authors may not be used for publicity purposes.
+ *
+ * No rights are granted for use of trade names, trademarks, or service marks
+ * which are in The Program if any.
+ *
+ * Licensee must indemnify licensors and authors for any liability that these
+ * contractual assumptions impose on licensors and authors.
+ *
+ * To the extent this program is licensed as part of the Commercial versions of
+ * Teragrep, the applicable Commercial License may apply to this file if you as
+ * a licensee so wish it.
+ */
+package com.teragrep.aer_02;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.Objects;
+
+public final class Hostname {
+
+    private final String defaultHostname;
+    private static final Logger LOGGER = LoggerFactory.getLogger(Hostname.class);
+
+    public Hostname(final String defaultHostname) {
+        this.defaultHostname = defaultHostname;
+    }
+
+    public String hostname() {
+        String rv;
+        try {
+            rv = InetAddress.getLocalHost().getHostName();
+        }
+        catch (UnknownHostException e) {
+            rv = defaultHostname;
+            LOGGER.warn("Could not determine hostname, defaulting to <{}>", defaultHostname, e);
+        }
+        return rv;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        Hostname hostname = (Hostname) o;
+        return Objects.equals(defaultHostname, hostname.defaultHostname);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(defaultHostname);
+    }
+}

src/main/java/com/teragrep/aer_02/SyslogBridge.java

@@ -45,11 +45,16 @@
  */
 package com.teragrep.aer_02;
 
+import com.codahale.metrics.MetricRegistry;
 import com.microsoft.azure.functions.*;
 import com.microsoft.azure.functions.annotation.*;
 import com.teragrep.aer_02.config.source.EnvironmentSource;
-import com.teragrep.aer_02.config.source.Sourceable;
+import com.teragrep.aer_02.metrics.JmxReport;
+import com.teragrep.aer_02.metrics.PrometheusReport;
+import com.teragrep.aer_02.metrics.Report;
+import com.teragrep.aer_02.metrics.Slf4jReport;
 import io.prometheus.client.CollectorRegistry;
+import io.prometheus.client.dropwizard.DropwizardExports;
 import io.prometheus.client.exporter.common.TextFormat;
 
 import java.io.IOException;
@@ -64,6 +69,8 @@
 public class SyslogBridge {
 
     private EventDataConsumer consumer = null;
+    private Report report = null;
+    private MetricRegistry metricRegistry = null;
 
     @FunctionName("metrics")
     public HttpResponseMessage metrics(
@@ -113,9 +120,24 @@ public void eventHubTriggerToSyslog(
         context.getLogger().fine("eventHubTriggerToSyslog triggered");
         context.getLogger().fine("Got events: " + events.length);
 
+        if (metricRegistry == null) {
+            metricRegistry = new MetricRegistry();
+        }
+
+        if (report == null) {
+            report = new JmxReport(
+                    new Slf4jReport(new PrometheusReport(new DropwizardExports(metricRegistry)), metricRegistry),
+                    metricRegistry
+            );
+            report.start();
+        }
+
         if (consumer == null) {
-            final Sourceable configSource = new EnvironmentSource();
-            consumer = new EventDataConsumer(configSource);
+            consumer = new EventDataConsumer(
+                    new EnvironmentSource(),
+                    new Hostname("localhost").hostname(),
+                    metricRegistry
+            );
         }
 
         for (int index = 0; index < events.length; index++) {

src/main/java/com/teragrep/aer_02/metrics/JmxReport.java

@@ -0,0 +1,76 @@
+/*
+ * Teragrep Eventhub Reader as an Azure Function
+ * Copyright (C) 2024 Suomen Kanuuna Oy
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://github.com/teragrep/teragrep/blob/main/LICENSE>.
+ *
+ *
+ * Additional permission under GNU Affero General Public License version 3
+ * section 7
+ *
+ * If you modify this Program, or any covered work, by linking or combining it
+ * with other code, such other code is not for that reason alone subject to any
+ * of the requirements of the GNU Affero GPL version 3 as long as this Program
+ * is the same Program as licensed from Suomen Kanuuna Oy without any additional
+ * modifications.
+ *
+ * Supplemented terms under GNU Affero General Public License version 3
+ * section 7
+ *
+ * Origin of the software must be attributed to Suomen Kanuuna Oy. Any modified
+ * versions must be marked as "Modified version of" The Program.
+ *
+ * Names of the licensors and authors may not be used for publicity purposes.
+ *
+ * No rights are granted for use of trade names, trademarks, or service marks
+ * which are in The Program if any.
+ *
+ * Licensee must indemnify licensors and authors for any liability that these
+ * contractual assumptions impose on licensors and authors.
+ *
+ * To the extent this program is licensed as part of the Commercial versions of
+ * Teragrep, the applicable Commercial License may apply to this file if you as
+ * a licensee so wish it.
+ */
+package com.teragrep.aer_02.metrics;
+
+import com.codahale.metrics.MetricRegistry;
+import com.codahale.metrics.jmx.JmxReporter;
+
+public final class JmxReport implements Report {
+
+    private final Report report;
+    private final JmxReporter jmxReporter;
+
+    public JmxReport(final Report report, final MetricRegistry metricRegistry) {
+        this(report, JmxReporter.forRegistry(metricRegistry).build());
+    }
+
+    public JmxReport(final Report report, final JmxReporter jmxReporter) {
+        this.report = report;
+        this.jmxReporter = jmxReporter;
+    }
+
+    @Override
+    public void start() {
+        jmxReporter.start();
+        report.start();
+    }
+
+    @Override
+    public void close() throws Exception {
+        report.close();
+        jmxReporter.close();
+    }
+}

src/main/java/com/teragrep/aer_02/metrics/PrometheusReport.java

@@ -0,0 +1,68 @@
+/*
+ * Teragrep Eventhub Reader as an Azure Function
+ * Copyright (C) 2024 Suomen Kanuuna Oy
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://github.com/teragrep/teragrep/blob/main/LICENSE>.
+ *
+ *
+ * Additional permission under GNU Affero General Public License version 3
+ * section 7
+ *
+ * If you modify this Program, or any covered work, by linking or combining it
+ * with other code, such other code is not for that reason alone subject to any
+ * of the requirements of the GNU Affero GPL version 3 as long as this Program
+ * is the same Program as licensed from Suomen Kanuuna Oy without any additional
+ * modifications.
+ *
+ * Supplemented terms under GNU Affero General Public License version 3
+ * section 7
+ *
+ * Origin of the software must be attributed to Suomen Kanuuna Oy. Any modified
+ * versions must be marked as "Modified version of" The Program.
+ *
+ * Names of the licensors and authors may not be used for publicity purposes.
+ *
+ * No rights are granted for use of trade names, trademarks, or service marks
+ * which are in The Program if any.
+ *
+ * Licensee must indemnify licensors and authors for any liability that these
+ * contractual assumptions impose on licensors and authors.
+ *
+ * To the extent this program is licensed as part of the Commercial versions of
+ * Teragrep, the applicable Commercial License may apply to this file if you as
+ * a licensee so wish it.
+ */
+package com.teragrep.aer_02.metrics;
+
+import io.prometheus.client.Collector;
+import io.prometheus.client.CollectorRegistry;
+
+public final class PrometheusReport implements Report {
+
+    private final Collector collector;
+
+    public PrometheusReport(final Collector collector) {
+        this.collector = collector;
+    }
+
+    @Override
+    public void start() {
+        CollectorRegistry.defaultRegistry.register(collector);
+    }
+
+    @Override
+    public void close() {
+        CollectorRegistry.defaultRegistry.unregister(collector);
+    }
+}