log the full version name of CDA

this can be collected by dashboarding in order to compare metrics between version changes

cwms-data-api/build.gradle

@@ -134,6 +134,8 @@ dependencies {
     tomcatLibs "org.apache.tomcat.embed:tomcat-embed-jasper:$tomcatVersion"
     tomcatLibs "org.apache.tomcat:tomcat-juli:$tomcatVersion"
     tomcatLibs "org.apache.tomcat:tomcat-jdbc:$tomcatVersion"
+    tomcatLibs "com.google.flogger:flogger:0.7.4"
+    tomcatLibs "com.google.flogger:flogger-system-backend:0.7.4"
 
     testImplementation "com.github.h-thurow:tomcat8jndi:1.0.0"
 
@@ -180,6 +182,10 @@ war {
     from "$buildDir/extra"
     from "src/resources/"
 
+    manifest {
+        attributes "build-version": project.version
+    }
+
     doLast {
         println(war.archiveFileName.toString())
         println("::set-output name=WARFILE::${project.name}-${project.version}.war")

cwms-data-api/src/main/java/cwms/cda/ApiServlet.java

@@ -105,12 +105,17 @@
 import javax.servlet.http.HttpServletResponse;
 import javax.sql.DataSource;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.PrintWriter;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.time.DateTimeException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
+import java.util.jar.Manifest;
 
 import static io.javalin.apibuilder.ApiBuilder.*;
 
@@ -178,6 +183,7 @@ public void destroy() {
 
     @Override
     public void init(ServletConfig config) throws ServletException {
+        logger.atInfo().log("Initializing CWMS Data API Version:  " + obtainFullVersion(config));
         metrics = (MetricRegistry)config.getServletContext()
                 .getAttribute(MetricsServlet.METRICS_REGISTRY);
         totalRequests = metrics.meter("cwms.dataapi.total_requests");
@@ -187,7 +193,6 @@ public void init(ServletConfig config) throws ServletException {
     @SuppressWarnings({"java:S125","java:S2095"}) // closed in destroy handler
     @Override
     public void init() {
-        logger.atInfo().log("Initializing API");
         JavalinValidation.register(UnitSystem.class, UnitSystem::systemFor);
         JavalinValidation.register(JooqDao.DeleteMethod.class, Controllers::getDeleteMethod);
         ObjectMapper om = new ObjectMapper();
@@ -301,6 +306,19 @@ public void init() {
                 .javalinServlet();
     }
 
+    private String obtainFullVersion(ServletConfig servletConfig) throws ServletException {
+        String relativeWARPath = "/META-INF/MANIFEST.MF";
+        String absoluteDiskPath = servletConfig.getServletContext().getRealPath(relativeWARPath);
+        Path path = Paths.get(absoluteDiskPath);
+
+        try (InputStream inputStream = Files.newInputStream(path)) {
+            Manifest manifest = new Manifest(inputStream);
+            return manifest.getMainAttributes().getValue("build-version");
+        } catch (IOException e) {
+            throw new ServletException("Error obtaining servlet version", e);
+        }
+    }
+
     private CdaAccessManager buildAccessManager(String provider) {
         try {
             AccessManagers ams = new AccessManagers();