Add logging statements

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/discovery/ApplicationDiscoveryListener.java

@@ -84,6 +84,8 @@ public class ApplicationDiscoveryListener {
 					String applicationId = register(instance);
 					staleApplicationIds.remove(applicationId);
 				}
+			} else {
+				LOGGER.debug("Ignoring discovered service {}", serviceId);
 			}
 		}
 		for (String staleApplicationId : staleApplicationIds) {
@@ -107,6 +109,7 @@ public class ApplicationDiscoveryListener {
 		try {
 			Application application = converter.convert(instance);
 			if (application != null) {
+				LOGGER.debug("Registering discovered application {}", application);
 				return registry.register(application).getId();
 			} else {
 				LOGGER.warn("No application for service {} registered", instance);

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/discovery/DefaultServiceInstanceConverter.java

@@ -20,6 +20,8 @@ import static org.apache.commons.lang.StringUtils.stripStart;
 
 import java.net.URI;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.cloud.client.ServiceInstance;
 import org.springframework.web.util.UriComponentsBuilder;
 
@@ -35,6 +37,8 @@ import de.codecentric.boot.admin.model.Application;
  * @author Johannes Edmeier
  */
 public class DefaultServiceInstanceConverter implements ServiceInstanceConverter {
+	private static final Logger LOGGER = LoggerFactory
+			.getLogger(DefaultServiceInstanceConverter.class);
 	private static final String KEY_MANAGEMENT_PORT = "management.port";
 	private static final String KEY_MANAGEMENT_PATH = "management.context-path";
 	private static final String KEY_HEALTH_PATH = "health.path";
@@ -43,6 +47,10 @@ public class DefaultServiceInstanceConverter implements ServiceInstanceConverter
 
 	@Override
 	public Application convert(ServiceInstance instance) {
+		LOGGER.debug("Converting service '{}' running at '{}' with metadata {}",
+				instance.getServiceId(),
+				instance.getUri(), instance.getMetadata());
+
 		Application.Builder builder = Application.create(instance.getServiceId());
 		URI healthUrl = getHealthUrl(instance);
 		if (healthUrl != null) {

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/web/servlet/resource/ConcatenatingResourceResolver.java

@@ -51,6 +51,9 @@ public class ConcatenatingResourceResolver extends AbstractResourceResolver {
 			List<? extends Resource> locations, ResourceResolverChain chain) {
 		String filename = StringUtils.getFilename(requestPath);
 		try {
+			if (logger.isDebugEnabled()) {
+				logger.debug("Creating concatenated resource '" + filename + "' from " + locations);
+			}
 			return new InMemoryFileResource(filename, buildDescription(locations),
 					getContent(locations), getLastModified(locations));
 		} catch (IOException ex) {

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/web/servlet/resource/PreferMinifiedFilteringResourceResolver.java

@@ -33,7 +33,6 @@ import org.springframework.web.servlet.resource.ResourceResolverChain;
  * @author Johannes Edmeier
  */
 public class PreferMinifiedFilteringResourceResolver extends AbstractResourceResolver {
-
 	private final String extensionPrefix;
 
 	public PreferMinifiedFilteringResourceResolver(String extensionPrefix) {
@@ -43,7 +42,7 @@ public class PreferMinifiedFilteringResourceResolver extends AbstractResourceRes
 	@Override
 	protected Resource resolveResourceInternal(HttpServletRequest request, String requestPath,
 			List<? extends Resource> locations, ResourceResolverChain chain) {
-		List<Resource> newLocations = new ArrayList<Resource>(locations.size());
+		List<Resource> newLocations = new ArrayList<>(locations.size());
 
 		for (Resource location : locations) {
 			Resource minified = findMinified(location);
@@ -60,6 +59,10 @@ public class PreferMinifiedFilteringResourceResolver extends AbstractResourceRes
 			Resource minified = resource
 					.createRelative(basename + extensionPrefix + '.' + extension);
 			if (minified.exists()) {
+				if (logger.isDebugEnabled()) {
+					logger.debug("Found minified file for '" + resource.getFilename() + "': '"
+							+ minified.getFilename() + "'");
+				}
 				return minified;
 			}
 		} catch (IOException ex) {

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/web/servlet/resource/ResourcePatternResolvingResourceResolver.java

@@ -50,6 +50,10 @@ public class ResourcePatternResolvingResourceResolver extends AbstractResourceRe
 			List<? extends Resource> locations, ResourceResolverChain chain) {
 		try {
 			Resource[] resources = resourcePatternResolver.getResources(pattern);
+			if (logger.isDebugEnabled()) {
+				logger.debug(
+						"Resolved Resources for '" + pattern + "': " + Arrays.toString(resources));
+			}
 			return chain.resolveResource(request, requestPath, Arrays.asList(resources));
 		} catch (IOException ex) {
 			throw new ResourceAccessException("Couldn't resolve resources for \"" + pattern + "\"",