Version metric should be a string instead of an integer.

components/proxy/src/main/java/com/hotels/styx/Version.java

@@ -23,10 +23,8 @@
 import java.io.InputStreamReader;
 import java.io.Reader;
 import java.util.Objects;
-import java.util.Optional;
 
 import static com.google.common.base.Objects.toStringHelper;
-import static java.lang.Integer.parseInt;
 import static org.slf4j.LoggerFactory.getLogger;
 
 /**
@@ -76,31 +74,7 @@ public String releaseVersion() {
         return releaseTag.substring(firstDot + 1);
     }
 
-    public Optional<Integer> buildNumber() {
-        String releaseVersion = releaseVersion();
 
-        Optional<String> buildNumberAsString = extractFinalInt(releaseVersion);
-
-        return buildNumberAsString.flatMap(this::parseInteger);
-    }
-
-    private Optional<String> extractFinalInt(String dotSeparatedIntegers) {
-        int lastDot = dotSeparatedIntegers.lastIndexOf('.');
-
-        if (lastDot == -1 || lastDot == dotSeparatedIntegers.length() - 1) {
-            return Optional.empty();
-        }
-
-        return Optional.of(dotSeparatedIntegers.substring(lastDot + 1));
-    }
-
-    private Optional<Integer> parseInteger(String string) {
-        try {
-            return Optional.of(parseInt(string));
-        } catch (NumberFormatException e) {
-            return Optional.empty();
-        }
-    }
 
     @Override
     public String toString() {

components/proxy/src/main/java/com/hotels/styx/startup/CoreMetrics.java

@@ -30,7 +30,6 @@
 
 import java.lang.management.RuntimeMXBean;
 import java.time.Duration;
-import java.util.Optional;
 
 import static java.lang.String.format;
 import static java.lang.management.ManagementFactory.getPlatformMBeanServer;
@@ -47,23 +46,13 @@ private CoreMetrics() {
     }
 
     public static void registerCoreMetrics(Version buildInfo, MetricRegistry metrics) {
-        registerVersionMetric(buildInfo, metrics);
+        registerVersionMetric(metrics, buildInfo.releaseVersion());
         registerJvmMetrics(metrics);
         metrics.register("os", new OperatingSystemMetricSet());
     }
 
-    private static void registerVersionMetric(Version buildInfo, MetricRegistry metrics) {
-        Optional<Integer> buildNumber = buildInfo.buildNumber();
-
-        if (buildNumber.isPresent()) {
-            registerVersionMetric(metrics, buildNumber.get());
-        } else {
-            LOG.warn("Could not acquire build number from release version: {}", buildInfo);
-        }
-    }
-
-    private static void registerVersionMetric(MetricRegistry metricRegistry, Integer buildNumber) {
-        Gauge<Integer> versionGauge = () -> buildNumber;
+    private static void registerVersionMetric(MetricRegistry metricRegistry, String versionNumber) {
+        Gauge<String> versionGauge = () -> versionNumber;
 
         metricRegistry.scope("styx").register("version.buildnumber", versionGauge);
     }

components/proxy/src/test/java/com/hotels/styx/VersionTest.java

@@ -19,6 +19,7 @@
 
 import static com.hotels.styx.Version.newVersion;
 import static com.hotels.styx.Version.readVersionFrom;
+import static com.hotels.styx.support.matchers.IsOptional.isPresent;
 import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
@@ -29,6 +30,7 @@ public class VersionTest {
     public void readBuildInfoFromTheSpecifiedPath() {
         Version version = readVersionFrom("/version.json");
         assertThat(version.releaseTag(), containsString("STYX"));
+        assertThat(version.releaseVersion(), is("0.0-125"));
     }
 
     @Test

components/proxy/src/test/java/com/hotels/styx/startup/CoreMetricsTest.java

@@ -28,7 +28,7 @@
 import static org.hamcrest.Matchers.is;
 
 public class CoreMetricsTest {
-    private final Version version = new Version("1.2.3");
+    private final Version version = new Version("STYX.1.2.3");
 
     @Test
     public void registersVersionMetric() {
@@ -37,7 +37,7 @@ public void registersVersionMetric() {
 
         Gauge gauge = metrics.getGauges().get("styx.version.buildnumber");
 
-        assertThat(gauge.getValue(), is(3));
+        assertThat(gauge.getValue(), is("1.2.3"));
     }
 
     @Test

components/proxy/src/test/resources/version.json

@@ -0,0 +1,3 @@
+{
+    "release.tag": "STYX.0.0-125"
+}