sabhyankar commented on a change in pull request #11950: URL: https://github.com/apache/beam/pull/11950#discussion_r438777187
########## File path: sdks/java/io/splunk/src/main/java/org/apache/beam/sdk/io/splunk/HttpEventPublisher.java ########## @@ -0,0 +1,346 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.beam.sdk.io.splunk; + +import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkNotNull; + +import com.google.api.client.http.ByteArrayContent; +import com.google.api.client.http.GenericUrl; +import com.google.api.client.http.HttpBackOffUnsuccessfulResponseHandler; +import com.google.api.client.http.HttpBackOffUnsuccessfulResponseHandler.BackOffRequired; +import com.google.api.client.http.HttpContent; +import com.google.api.client.http.HttpMediaType; +import com.google.api.client.http.HttpRequest; +import com.google.api.client.http.HttpRequestFactory; +import com.google.api.client.http.HttpResponse; +import com.google.api.client.http.apache.v2.ApacheHttpTransport; +import com.google.api.client.util.ExponentialBackOff; +import com.google.auto.value.AutoValue; +import com.google.gson.Gson; +import com.google.gson.GsonBuilder; +import java.io.IOException; +import java.io.UnsupportedEncodingException; +import java.security.KeyManagementException; +import java.security.KeyStoreException; +import java.security.NoSuchAlgorithmException; +import java.util.List; +import javax.annotation.Nullable; +import javax.net.ssl.HostnameVerifier; +import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting; +import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Joiner; +import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList; +import org.apache.http.client.config.CookieSpecs; +import org.apache.http.client.config.RequestConfig; +import org.apache.http.conn.ssl.DefaultHostnameVerifier; +import org.apache.http.conn.ssl.NoopHostnameVerifier; +import org.apache.http.conn.ssl.SSLConnectionSocketFactory; +import org.apache.http.conn.ssl.TrustStrategy; +import org.apache.http.impl.client.CloseableHttpClient; +import org.apache.http.impl.client.HttpClientBuilder; +import org.apache.http.ssl.SSLContextBuilder; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * A utility class that helps write {@link SplunkEvent} records to Splunk's Http Event Collector + * (HEC) endpoint. + */ +@AutoValue +abstract class HttpEventPublisher { + + private static final Logger LOG = LoggerFactory.getLogger(HttpEventPublisher.class); + + private static final int DEFAULT_MAX_CONNECTIONS = 1; + + private static final boolean DEFAULT_DISABLE_CERTIFICATE_VALIDATION = false; + + private static final Gson GSON = + new GsonBuilder().setFieldNamingStrategy(f -> f.getName().toLowerCase()).create(); + + @VisibleForTesting static final String HEC_URL_PATH = "services/collector/event"; + + private static final HttpMediaType MEDIA_TYPE = + new HttpMediaType("application/json;profile=urn:splunk:event:1.0;charset=utf-8"); + + private static final String CONTENT_TYPE = + Joiner.on('/').join(MEDIA_TYPE.getType(), MEDIA_TYPE.getSubType()); + + private static final String AUTHORIZATION_SCHEME = "Splunk %s"; + + private static final String HTTPS_PROTOCOL_PREFIX = "https"; + + /** Provides a builder for creating a {@link HttpEventPublisher}. */ + static Builder newBuilder() { + return new AutoValue_HttpEventPublisher.Builder(); + } + + abstract ApacheHttpTransport transport(); + + abstract HttpRequestFactory requestFactory(); + + abstract GenericUrl genericUrl(); + + abstract String token(); + + @Nullable + abstract Integer maxElapsedMillis(); + + abstract Boolean disableCertificateValidation(); + + /** + * Executes a POST for the list of {@link SplunkEvent} objects into Splunk's Http Event Collector + * endpoint. + * + * @param events list of {@link SplunkEvent}s + * @return {@link HttpResponse} for the POST + */ + HttpResponse execute(List<SplunkEvent> events) throws IOException { + + HttpContent content = getContent(events); + HttpRequest request = requestFactory().buildPostRequest(genericUrl(), content); + + HttpBackOffUnsuccessfulResponseHandler responseHandler = + new HttpBackOffUnsuccessfulResponseHandler(getConfiguredBackOff()); + + responseHandler.setBackOffRequired(BackOffRequired.ON_SERVER_ERROR); + + request.setUnsuccessfulResponseHandler(responseHandler); + setHeaders(request, token()); + + return request.execute(); + } + + /** + * Same as {@link HttpEventPublisher#execute(List)} but with a single {@link SplunkEvent}. + * + * @param event {@link SplunkEvent} object + */ + HttpResponse execute(SplunkEvent event) throws IOException { + return this.execute(ImmutableList.of(event)); + } + + /** + * Returns an {@link ExponentialBackOff} with the right settings. + * + * @return {@link ExponentialBackOff} object + */ + @VisibleForTesting + ExponentialBackOff getConfiguredBackOff() { + return new ExponentialBackOff.Builder().setMaxElapsedTimeMillis(maxElapsedMillis()).build(); + } + + /** Shutsdown connection manager and releases all resources. */ + void close() throws IOException { + if (transport() != null) { + LOG.info("Closing publisher transport."); + transport().shutdown(); + } + } + + /** + * Utility method to set Authorization and other relevant http headers into the {@link + * HttpRequest}. + * + * @param request {@link HttpRequest} object to add headers to + * @param token Splunk's HEC authorization token + */ + private void setHeaders(HttpRequest request, String token) { + request.getHeaders().setAuthorization(String.format(AUTHORIZATION_SCHEME, token)); + } + + /** + * Marshals a list of {@link SplunkEvent}s into an {@link HttpContent} object that can be used to + * create an {@link HttpRequest}. + * + * @param events list of {@link SplunkEvent}s + * @return {@link HttpContent} that can be used to create an {@link HttpRequest}. + */ + @VisibleForTesting + HttpContent getContent(List<SplunkEvent> events) { + String payload = getStringPayload(events); + LOG.debug("Payload content: {}", payload); + return ByteArrayContent.fromString(CONTENT_TYPE, payload); + } + + /** Extracts the payload string from a list of {@link SplunkEvent}s. */ + @VisibleForTesting + String getStringPayload(List<SplunkEvent> events) { + StringBuilder sb = new StringBuilder(); + events.forEach(event -> sb.append(GSON.toJson(event))); Review comment: Its not necessary to have newlines or separators as the batch protocol for Splunk's HEC is [simple event objects stacked one after the other and not necessarily in a JSON array.](https://docs.splunk.com/Documentation/Splunk/8.0.4/Data/FormateventsforHTTPEventCollector#Examples) ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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