Feat: S3 Object Lambda support (#229)

Co-authored-by: Carl Zogheib <[email protected]>

Author: msailes

aws-lambda-java-events/src/main/java/com/amazonaws/services/lambda/runtime/events/S3ObjectLambdaEvent.java

@@ -0,0 +1,136 @@
+package com.amazonaws.services.lambda.runtime.events;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.Map;
+
+/**
+ * Event to allow transformations to occur before an S3 object is returned to the calling service.
+ *
+ * <strong>Documentation</strong>
+ *
+ * <a href="https://docs.aws.amazon.com/AmazonS3/latest/userguide/olap-writing-lambda.html">Writing and debugging Lambda functions for S3 Object Lambda Access Points</a>
+ *
+ * <strong>Example:</strong>
+ *
+ * <pre>
+ * <code>import com.amazonaws.services.lambda.runtime.Context;
+ * import com.amazonaws.services.lambda.runtime.events.S3ObjectLambdaEvent;
+ * import org.apache.http.client.fluent.Request;
+ * import software.amazon.awssdk.services.s3.S3Client;
+ * import software.amazon.awssdk.services.s3.model.WriteGetObjectResponseRequest;
+ *
+ * import java.io.IOException;
+ *
+ * import static software.amazon.awssdk.core.sync.RequestBody.fromString;
+ *
+ * public class S3ObjectRequestHandler {
+ *
+ *      private static final S3Client s3Client = S3Client.create();
+ *
+ *      public void handleRequest(S3ObjectLambdaEvent event, Context context) throws IOException {
+ *          String s3Body = Request.Get(event.inputS3Url()).execute().returnContent().asString();
+ *
+ *          String responseBody = s3Body.toUpperCase();
+ *
+ *          WriteGetObjectResponseRequest request = WriteGetObjectResponseRequest.builder()
+ *              .requestRoute(event.outputRoute())
+ *              .requestToken(event.outputToken())
+ *              .build();
+ *          s3Client.writeGetObjectResponse(request, fromString(responseBody));
+ *      }
+ * }
+ * </code>
+ * </pre>
+ */
+
+@Data
+@Builder(setterPrefix = "with")
+@NoArgsConstructor
+@AllArgsConstructor
+public class S3ObjectLambdaEvent {
+
+    private String xAmzRequestId;
+    private GetObjectContext getObjectContext;
+    private Configuration configuration;
+    private UserRequest userRequest;
+    private UserIdentity userIdentity;
+    private String protocolVersion;
+
+    /**
+     * A pre-signed URL that can be used to fetch the original object from Amazon S3.
+     *
+     * The URL is signed using the original caller’s identity, and their permissions
+     * will apply when the URL is used. If there are signed headers in the URL, the
+     * Lambda function must include these in the call to Amazon S3, except for the Host.
+     *
+     * @return A pre-signed URL that can be used to fetch the original object from Amazon S3.
+     */
+    public String inputS3Url() {
+        return getGetObjectContext().getInputS3Url();
+    }
+
+    /**
+     * A routing token that is added to the S3 Object Lambda URL when the Lambda function
+     * calls the S3 API WriteGetObjectResponse.
+     *
+     * @return the outputRoute
+     */
+    public String outputRoute() {
+        return getGetObjectContext().getOutputRoute();
+    }
+
+    /**
+     * An opaque token used by S3 Object Lambda to match the WriteGetObjectResponse call
+     * with the original caller.
+     *
+     * @return the outputToken
+     */
+    public String outputToken() {
+        return getGetObjectContext().getOutputToken();
+    }
+
+    @Data
+    @Builder(setterPrefix = "with")
+    @NoArgsConstructor
+    @AllArgsConstructor
+    public static class GetObjectContext {
+        private String inputS3Url;
+        private String outputRoute;
+        private String outputToken;
+    }
+
+    @Data
+    @Builder(setterPrefix = "with")
+    @NoArgsConstructor
+    @AllArgsConstructor
+    public static class Configuration {
+        private String accessPointArn;
+        private String supportingAccessPointArn;
+        private String payload;
+    }
+
+    @Data
+    @Builder(setterPrefix = "with")
+    @NoArgsConstructor
+    @AllArgsConstructor
+    public static class UserRequest {
+        private String url;
+        private Map<String, String> headers;
+    }
+
+    @Data
+    @Builder(setterPrefix = "with")
+    @NoArgsConstructor
+    @AllArgsConstructor
+    public static class UserIdentity {
+        private String type;
+        private String principalId;
+        private String arn;
+        private String accountId;
+        private String accessKeyId;
+    }
+}