Switch Custom Metrics Shipment (#109)

* Switch Custom Metrics Shipment

SAP BTP Application Logging has been changed to accept custom metrics within
the log message stream. For this the messages need to be in JSON format and
contain a field "type":"metrics" and an array of metrics in field "metrics". The prior
approach using an Http endpoint is deprecated for removal. This commit changes
cf-java-logging-support to provide custom metrics according to the new format by
writing the correct JSON to `System.out`.

* Run Formatter and Cleanup over changed files

This commit contains changes by applying the formatter and cleanup configuration
across all files of the PR.

Author: KarstenSchnitter

cf-java-monitoring-custom-metrics-clients/cf-custom-metrics-clients-core/pom.xml

@@ -12,10 +12,6 @@
 	<name>cf-java-monitoring-custom-metrics-clients-core</name>
 
 	<dependencies>
-		<dependency>
-			<groupId>org.apache.httpcomponents</groupId>
-			<artifactId>httpclient</artifactId>
-		</dependency>
 		<dependency>
 			<groupId>com.google.code.gson</groupId>
 			<artifactId>gson</artifactId>

cf-java-monitoring-custom-metrics-clients/cf-custom-metrics-clients-core/src/main/java/com/sap/cloud/cf/monitoring/client/MonitoringClient.java

@@ -9,15 +9,15 @@ public interface MonitoringClient {
 
     /**
      * Send single metric to the Monitoring service
-     * 
+     *
      * @param metric
      * @throws MonitoringClientException
      */
     void send(Metric metric) throws MonitoringClientException;
 
     /**
      * Send list of metrics to the Monitoring service
-     * 
+     *
      * @param metrics
      * @throws MonitoringClientException
      */

cf-java-monitoring-custom-metrics-clients/cf-custom-metrics-clients-core/src/main/java/com/sap/cloud/cf/monitoring/client/MonitoringClientBuilder.java

@@ -1,58 +1,19 @@
 package com.sap.cloud.cf.monitoring.client;
 
 import static com.sap.cloud.cf.monitoring.client.utils.Utils.checkNotNull;
-import static java.lang.String.format;
 
-import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.util.Arrays;
 import java.util.List;
 
-import org.apache.http.Header;
-import org.apache.http.HttpEntity;
-import org.apache.http.HttpHeaders;
-import org.apache.http.HttpStatus;
-import org.apache.http.auth.AuthenticationException;
-import org.apache.http.auth.UsernamePasswordCredentials;
-import org.apache.http.client.methods.CloseableHttpResponse;
-import org.apache.http.client.methods.HttpPost;
-import org.apache.http.entity.StringEntity;
-import org.apache.http.impl.auth.BasicScheme;
-import org.apache.http.impl.client.CloseableHttpClient;
-import org.apache.http.impl.client.HttpClients;
-import org.apache.http.util.EntityUtils;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import com.google.gson.Gson;
-import com.sap.cloud.cf.monitoring.client.configuration.ConfigurationProvider;
 import com.sap.cloud.cf.monitoring.client.exceptions.MonitoringClientException;
 import com.sap.cloud.cf.monitoring.client.model.Metric;
-import com.sap.cloud.cf.monitoring.client.model.api.MetricRequest;
+import com.sap.cloud.cf.monitoring.client.model.MetricEnvelope;
 
 public class MonitoringClientBuilder {
-    private static final Logger LOG = LoggerFactory.getLogger(MonitoringClientBuilder.class);
-
-    private ConfigurationProvider provider;
-    private CloseableHttpClient client = null;
-
-    public MonitoringClientBuilder setConfigurationProvider(ConfigurationProvider provider) {
-        checkNotNull(provider, "configuration provider");
-        this.provider = provider;
-        return this;
-    }
-
-    public MonitoringClientBuilder setHttpClient(CloseableHttpClient client) {
-        checkNotNull(client, "http client");
-        this.client = client;
-        return this;
-    }
 
     public MonitoringClient create() {
-        if (this.client == null) {
-            return new MonitoringClientImpl(this.provider);
-        }
-        return new MonitoringClientImpl(this.provider, this.client);
+        return new MonitoringClientImpl();
     }
 
     static class MonitoringClientImpl implements MonitoringClient {
@@ -61,25 +22,6 @@ static class MonitoringClientImpl implements MonitoringClient {
 
         private static final Gson gson = new Gson();
 
-        private ConfigurationProvider configurationProvider;
-        private CloseableHttpClient client;
-        private UsernamePasswordCredentials credentials;
-
-        private static CloseableHttpClient createHttpClient(ConfigurationProvider provider) {
-            return HttpClients.custom().useSystemProperties().build();
-        }
-
-        MonitoringClientImpl(ConfigurationProvider provider) {
-            this(provider, createHttpClient(provider));
-        }
-
-        MonitoringClientImpl(ConfigurationProvider provider, CloseableHttpClient client) {
-            checkNotNull(provider, "configuration provider");
-            checkNotNull(client, "client");
-            this.configurationProvider = provider;
-            this.client = client;
-        }
-
         @Override
         public void send(Metric metric) throws MonitoringClientException {
             checkNotNull(metric, "metric");
@@ -92,77 +34,9 @@ public void send(List<Metric> metrics) throws MonitoringClientException {
             if (metrics.isEmpty()) {
                 throw new IllegalArgumentException("The list of metrics cannot be empty");
             }
-            MetricRequest metricRequest = createMetricRequest(metrics);
-            String requestURL = createRequestURL();
-            processRequest(requestURL, metricRequest);
-        }
-
-        private void processRequest(String requestURL, MetricRequest metricRequest) {
-            HttpPost request = new HttpPost(requestURL);
-            request.setEntity(createEntity(metricRequest));
-            request.setHeader(HttpHeaders.CONTENT_TYPE, "application/json");
-            request.addHeader(basicSchema(request));
-
-            try (CloseableHttpResponse response = client.execute(request)) {
-                checkResponseCode(response);
-                EntityUtils.consumeQuietly(response.getEntity());
-            } catch (IOException e) {
-                throw new MonitoringClientException(
-                        "Error occured while trying to send metrics to the monitoring service", e);
-            }
-        }
-
-        private Header basicSchema(HttpPost request) {
-            try {
-                return new BasicScheme().authenticate(getCredentials(configurationProvider), request, null);
-            } catch (AuthenticationException e) {
-                LOG.error("Could not initialize BasicSchema");
-            }
-            return null;
-        }
-
-        private UsernamePasswordCredentials getCredentials(ConfigurationProvider provider) {
-            if (credentials == null) {
-                credentials =
-                    new UsernamePasswordCredentials(provider.getClientId(), new String(provider.getClientSecret()));
-            }
-            return credentials;
-        }
-
-        private void checkResponseCode(CloseableHttpResponse response) {
-            int statusCode = response.getStatusLine().getStatusCode();
-            if (HttpStatus.SC_CREATED != statusCode) {
-                String message = extractErrorMessage(response);
-                throw new MonitoringClientException(format(
-                    "Unexpected response code from monitoring service: %d, message: %s", statusCode, message));
-            }
-        }
-
-        private String extractErrorMessage(CloseableHttpResponse response) {
-            try {
-                return EntityUtils.toString(response.getEntity());
-            } catch (Exception e) { //NOSONAR
-                LOG.warn("Cannot extract the error message from the response", e);
-                return "";
-            }
-        }
-
-        private HttpEntity createEntity(MetricRequest metricRequest) {
-            try {
-                return new StringEntity(gson.toJson(metricRequest));
-            } catch (UnsupportedEncodingException e) {
-                throw new MonitoringClientException("Unable to create request entity", e);
-            }
-        }
-
-        private String createRequestURL() {
-            return String.format(REQUEST_URL_TEMPLATE, configurationProvider.getUrl(),
-                configurationProvider.getApplicationGUID(), configurationProvider.getInstanceGUID());
-        }
-
-        private MetricRequest createMetricRequest(List<Metric> metrics) {
-            return new MetricRequest(configurationProvider.getApplicationGUID(),
-                    configurationProvider.getInstanceGUID(), configurationProvider.getInstanceIndex(), metrics);
+            MetricEnvelope envelope = new MetricEnvelope(metrics);
+            String message = gson.toJson(envelope);
+            System.out.println(message);
         }
     }
 }