adding backend as a service with lambda + api gateway + dynamodb

pom.xml

@@ -49,7 +49,9 @@
         <slf4j.version>1.7.21</slf4j.version>
         <logback.version>1.1.7</logback.version>
         <aws-lambda-core.version>1.1.0</aws-lambda-core.version>
+        <aws-java-sdk-dynamodb.version>1.11.289</aws-java-sdk-dynamodb.version>
         <aws-lambda-log4j.version>1.0.0</aws-lambda-log4j.version>
+        <aws-lambda-java-events.version>2.0.1</aws-lambda-java-events.version>
         <jackson.version>2.8.5</jackson.version>
     </properties>
     <modules>

serverless/pom.xml

@@ -35,6 +35,26 @@
             <artifactId>aws-lambda-java-core</artifactId>
             <version>${aws-lambda-core.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.amazonaws</groupId>
+            <artifactId>aws-java-sdk-dynamodb</artifactId>
+            <version>${aws-java-sdk-dynamodb.version}</version>
+            <exclusions>
+                <exclusion>
+                    <groupId>com.amazonaws</groupId>
+                    <artifactId>aws-java-sdk-s3</artifactId>
+                </exclusion>
+                <exclusion>
+                    <groupId>com.amazonaws</groupId>
+                    <artifactId>aws-java-sdk-kms</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <dependency>
+            <groupId>com.amazonaws</groupId>
+            <artifactId>aws-lambda-java-events</artifactId>
+            <version>${aws-lambda-java-events.version}</version>
+        </dependency>
         <dependency>
             <groupId>com.amazonaws</groupId>
             <artifactId>aws-lambda-java-log4j</artifactId>

serverless/serverless.yml

@@ -21,7 +21,7 @@
 # THE SOFTWARE.
 #
 
-service: lambda-info-http-endpoint
+service: serverless-services
 
 frameworkVersion: ">=1.2.0 <2.0.0"
 
@@ -41,9 +41,62 @@ package:
   artifact: target/serverless.jar
 
 functions:
-  currentTime:
-    handler: com.iluwatar.serverless.api.LambdaInfoApiHandler
+  lambdaInfoApi:
+    handler: com.iluwatar.serverless.faas.api.LambdaInfoApiHandler
     events:
       - http:
           path: info
           method: get
+
+  savePerson:
+    handler: com.iluwatar.serverless.baas.api.SavePersonApiHandler
+    events:
+      - http:
+          path: api/person
+          method: post
+          cors: true
+          integration: lambda-proxy
+
+  getPerson:
+    handler: com.iluwatar.serverless.baas.api.FindPersonApiHandlerr
+    events:
+      - http:
+          path: api/person/{id}
+          method: get
+          cors: true
+          integration: lambda-proxy
+
+resources:
+  Resources:
+    DynamoDbTable:
+      Type: AWS::DynamoDB::Table
+      Properties:
+        TableName: persons
+        AttributeDefinitions:
+          - AttributeName: id
+            AttributeType: S
+        KeySchema:
+          - AttributeName: id
+            KeyType: HASH
+        ProvisionedThroughput:
+          ReadCapacityUnits: 1
+          WriteCapacityUnits: 1
+    DynamoDBIamPolicy:
+      Type: AWS::IAM::Policy
+      DependsOn: DynamoDbTable
+      Properties:
+        PolicyName: lambda-dynamodb
+        PolicyDocument:
+          Version: '2012-10-17'
+          Statement:
+            - Effect: Allow
+              Action:
+                - dynamodb:GetItem
+                - dynamodb:PutItem
+                - dynamodb:UpdateItem
+                - dynamodb:DeleteItem
+                - dynamodb:Query
+                - dynamodb:Scan
+              Resource: arn:aws:dynamodb:*:*:table/persons
+        Roles:
+          - Ref: IamRoleLambdaExecution

serverless/src/main/java/com/iluwatar/serverless/baas/api/AbstractDynamoDbHandler.java

@@ -0,0 +1,79 @@
+package com.iluwatar.serverless.baas.api;
+
+import com.amazonaws.regions.Regions;
+import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;
+import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClientBuilder;
+import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper;
+import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyResponseEvent;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import java.io.Serializable;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * abstract dynamodb handler
+ * @param <T> - serializable collection
+ */
+public abstract class AbstractDynamoDbHandler<T extends Serializable> {
+  private DynamoDBMapper dynamoDbMapper;
+
+  private ObjectMapper objectMapper;
+
+  public AbstractDynamoDbHandler() {
+    this.initAmazonDynamoDb();
+    this.objectMapper = new ObjectMapper();
+  }
+
+  private void initAmazonDynamoDb() {
+    AmazonDynamoDB amazonDynamoDb = AmazonDynamoDBClientBuilder
+        .standard()
+        .withRegion(Regions.US_EAST_1)
+        .build();
+
+    this.dynamoDbMapper = new DynamoDBMapper(amazonDynamoDb);
+  }
+
+  protected DynamoDBMapper getDynamoDbMapper() {
+    return this.dynamoDbMapper;
+  }
+
+  protected ObjectMapper getObjectMapper() {
+    return objectMapper;
+  }
+
+  public void setDynamoDbMapper(DynamoDBMapper dynamoDbMapper) {
+    this.dynamoDbMapper = dynamoDbMapper;
+  }
+
+  protected Map<String, String> headers() {
+    Map<String, String> headers = new HashMap<>();
+    headers.put("Content-Type", "application/json");
+
+    return headers;
+  }
+
+  /**
+   * API Gateway response
+   *
+   * @param statusCode - status code
+   * @param body - Object body
+   * @return - api gateway proxy response
+   */
+  protected APIGatewayProxyResponseEvent apiGatewayProxyResponseEvent(Integer statusCode, T body) {
+    APIGatewayProxyResponseEvent apiGatewayProxyResponseEvent =
+        new APIGatewayProxyResponseEvent().withHeaders(headers());
+    try {
+      apiGatewayProxyResponseEvent
+          .withStatusCode(statusCode)
+          .withBody(getObjectMapper()
+              .writeValueAsString(body));
+
+    } catch (JsonProcessingException jsonProcessingException) {
+      throw new RuntimeException(jsonProcessingException);
+    }
+
+    return apiGatewayProxyResponseEvent;
+  }
+}

serverless/src/main/java/com/iluwatar/serverless/baas/api/FindPersonApiHandler.java

@@ -0,0 +1,29 @@
+package com.iluwatar.serverless.baas.api;
+
+import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.RequestHandler;
+import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent;
+import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyResponseEvent;
+import com.iluwatar.serverless.baas.model.Person;
+import org.apache.log4j.Logger;
+
+/**
+ * find person from persons collection
+ * Created by dheeraj.mummar on 3/5/18.
+ */
+public class FindPersonApiHandler extends AbstractDynamoDbHandler
+    implements RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> {
+
+  private static final Logger LOG = Logger.getLogger(FindPersonApiHandler.class);
+  private static final Integer SUCCESS_STATUS_CODE = 200;
+
+  @Override
+  public APIGatewayProxyResponseEvent handleRequest(APIGatewayProxyRequestEvent apiGatewayProxyRequestEvent,
+                                                    Context context) {
+    LOG.info(apiGatewayProxyRequestEvent.getPathParameters());
+    Person person = this.getDynamoDbMapper().load(Person.class, apiGatewayProxyRequestEvent
+        .getPathParameters().get("id"));
+
+    return apiGatewayProxyResponseEvent(SUCCESS_STATUS_CODE, person);
+  }
+}

serverless/src/main/java/com/iluwatar/serverless/baas/api/SavePersonApiHandler.java

@@ -0,0 +1,39 @@
+package com.iluwatar.serverless.baas.api;
+
+import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.RequestHandler;
+import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent;
+import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyResponseEvent;
+import com.iluwatar.serverless.baas.model.Person;
+import org.apache.log4j.Logger;
+
+import java.io.IOException;
+
+/**
+ * save person into persons collection
+ * Created by dheeraj.mummar on 3/4/18.
+ */
+public class SavePersonApiHandler extends AbstractDynamoDbHandler
+    implements RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> {
+
+  private static final Logger LOG = Logger.getLogger(SavePersonApiHandler.class);
+  private static final Integer CREATED_STATUS_CODE = 201;
+  private static final Integer BAD_REQUEST_STATUS_CODE = 400;
+
+  @Override
+  public APIGatewayProxyResponseEvent handleRequest(APIGatewayProxyRequestEvent
+                                                apiGatewayProxyRequestEvent, Context context) {
+    APIGatewayProxyResponseEvent apiGatewayProxyResponseEvent;
+    Person person;
+    try {
+      person = getObjectMapper().readValue(apiGatewayProxyRequestEvent.getBody(), Person.class);
+      getDynamoDbMapper().save(person);
+      apiGatewayProxyResponseEvent = apiGatewayProxyResponseEvent(CREATED_STATUS_CODE, person);
+    } catch (IOException ioException) {
+      LOG.error("unable to parse body", ioException);
+      apiGatewayProxyResponseEvent = apiGatewayProxyResponseEvent(BAD_REQUEST_STATUS_CODE, null);
+    }
+
+    return apiGatewayProxyResponseEvent;
+  }
+}

serverless/src/main/java/com/iluwatar/serverless/baas/model/Address.java

@@ -0,0 +1,119 @@
+package com.iluwatar.serverless.baas.model;
+
+import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBAttribute;
+import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBDocument;
+
+import java.io.Serializable;
+
+/**
+ * Address Object
+ * Created by dheeraj.mummarareddy on 3/4/18.
+ */
+@DynamoDBDocument
+public class Address implements Serializable {
+
+  private static final long serialVersionUID = 6760844284799736970L;
+
+  private String addressLineOne;
+  private String addressLineTwo;
+  private String city;
+  private String state;
+  private String zipCode;
+
+  @DynamoDBAttribute(attributeName = "addressLineOne")
+  public String getAddressLineOne() {
+    return addressLineOne;
+  }
+
+  public void setAddressLineOne(String addressLineOne) {
+    this.addressLineOne = addressLineOne;
+  }
+
+  @DynamoDBAttribute(attributeName = "addressLineTwo")
+  public String getAddressLineTwo() {
+    return addressLineTwo;
+  }
+
+  public void setAddressLineTwo(String addressLineTwo) {
+    this.addressLineTwo = addressLineTwo;
+  }
+
+  @DynamoDBAttribute(attributeName = "city")
+  public String getCity() {
+    return city;
+  }
+
+  public void setCity(String city) {
+    this.city = city;
+  }
+
+  @DynamoDBAttribute(attributeName = "state")
+  public String getState() {
+    return state;
+  }
+
+  public void setState(String state) {
+    this.state = state;
+  }
+
+  @DynamoDBAttribute(attributeName = "zipCode")
+  public String getZipCode() {
+    return zipCode;
+  }
+
+  public void setZipCode(String zipCode) {
+    this.zipCode = zipCode;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+
+    Address address = (Address) o;
+
+    if (addressLineOne != null ? !addressLineOne.equals(address.addressLineOne) :
+        address.addressLineOne != null) {
+      return false;
+    }
+
+    if (addressLineTwo != null ? !addressLineTwo.equals(address.addressLineTwo) :
+        address.addressLineTwo != null) {
+      return false;
+    }
+
+    if (city != null ? !city.equals(address.city) : address.city != null) {
+      return false;
+    }
+    if (state != null ? !state.equals(address.state) : address.state != null) {
+      return false;
+    }
+    return zipCode != null ? zipCode.equals(address.zipCode) : address.zipCode == null;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = addressLineOne != null ? addressLineOne.hashCode() : 0;
+    result = 31 * result + (addressLineTwo != null ? addressLineTwo.hashCode() : 0);
+    result = 31 * result + (city != null ? city.hashCode() : 0);
+    result = 31 * result + (state != null ? state.hashCode() : 0);
+    result = 31 * result + (zipCode != null ? zipCode.hashCode() : 0);
+    return result;
+  }
+
+  @Override
+  public String toString() {
+    return "Address{"
+        + "addressLineOne='" + addressLineOne + '\''
+        + ", addressLineTwo='" + addressLineTwo + '\''
+        + ", city='" + city + '\''
+        + ", state='" + state + '\''
+        + ", zipCode='" + zipCode + '\''
+        + '}';
+  }
+}

serverless/src/main/java/com/iluwatar/serverless/baas/model/Person.java

@@ -0,0 +1,102 @@
+package com.iluwatar.serverless.baas.model;
+
+import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBAttribute;
+import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBAutoGeneratedKey;
+import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBHashKey;
+import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBTable;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import java.io.Serializable;
+
+/**
+ * Person Request
+ * Created by dheeraj.mummarareddy on 3/4/18.
+ */
+@DynamoDBTable(tableName = "persons")
+public class Person implements Serializable {
+
+  private static final long serialVersionUID = -3413087924608627075L;
+
+  private String id;
+  private String firstName;
+  private String lastName;
+  private Address address;
+
+  @JsonProperty(access = JsonProperty.Access.READ_ONLY)
+  @DynamoDBHashKey(attributeName = "id")
+  @DynamoDBAutoGeneratedKey
+  public String getId() {
+    return id;
+  }
+
+  public void setId(String id) {
+    this.id = id;
+  }
+
+  @DynamoDBAttribute(attributeName = "firstName")
+  public String getFirstName() {
+    return firstName;
+  }
+
+  public void setFirstName(String firstName) {
+    this.firstName = firstName;
+  }
+
+  @DynamoDBAttribute(attributeName = "lastName")
+  public String getLastName() {
+    return lastName;
+  }
+
+  public void setLastName(String lastName) {
+    this.lastName = lastName;
+  }
+
+  @DynamoDBAttribute(attributeName = "address")
+  public Address getAddress() {
+    return address;
+  }
+
+  public void setAddress(Address address) {
+    this.address = address;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+
+    Person person = (Person) o;
+
+    if (firstName != null ? !firstName.equals(person.firstName) : person.firstName != null) {
+      return false;
+    }
+
+    if (lastName != null ? !lastName.equals(person.lastName) : person.lastName != null) {
+      return false;
+    }
+
+    return address != null ? address.equals(person.address) : person.address == null;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = firstName != null ? firstName.hashCode() : 0;
+    result = 31 * result + (lastName != null ? lastName.hashCode() : 0);
+    result = 31 * result + (address != null ? address.hashCode() : 0);
+    return result;
+  }
+
+  @Override
+  public String toString() {
+    return "Person{"
+        + "id='" + id + '\''
+        + ", firstName='" + firstName + '\''
+        + ", lastName='" + lastName + '\''
+        + ", address=" + address
+        + '}';
+  }
+}

serverless/src/main/java/com/iluwatar/serverless/faas/ApiGatewayResponse.java

@@ -20,7 +20,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-package com.iluwatar.serverless;
+package com.iluwatar.serverless.faas;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;

serverless/src/main/java/com/iluwatar/serverless/faas/LambdaInfo.java

@@ -20,7 +20,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-package com.iluwatar.serverless;
+package com.iluwatar.serverless.faas;
 
 import java.io.Serializable;
 

serverless/src/main/java/com/iluwatar/serverless/faas/api/LambdaInfoApiHandler.java

@@ -20,13 +20,13 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-package com.iluwatar.serverless.api;
+package com.iluwatar.serverless.faas.api;
 
-import com.iluwatar.serverless.ApiGatewayResponse;
+import com.iluwatar.serverless.faas.ApiGatewayResponse;
 
 import com.amazonaws.services.lambda.runtime.Context;
 import com.amazonaws.services.lambda.runtime.RequestHandler;
-import com.iluwatar.serverless.LambdaInfo;
+import com.iluwatar.serverless.faas.LambdaInfo;
 import org.apache.log4j.BasicConfigurator;
 import org.apache.log4j.Logger;
 

serverless/src/test/java/com/illuwatar/serverless/baas/api/FindPersonApiHandlerTest.java

@@ -0,0 +1,49 @@
+package com.illuwatar.serverless.baas.api;
+
+import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper;
+import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent;
+import com.iluwatar.serverless.baas.api.FindPersonApiHandler;
+import com.iluwatar.serverless.baas.api.SavePersonApiHandler;
+import com.iluwatar.serverless.baas.model.Person;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+
+import java.util.Collections;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+/**
+ * Created by dheeraj.mummar on 3/5/18.
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class FindPersonApiHandlerTest {
+
+  private FindPersonApiHandler findPersonApiHandler;
+
+  @Mock
+  private DynamoDBMapper dynamoDbMapper;
+
+  @Before
+  public void setUp() {
+    this.findPersonApiHandler = new FindPersonApiHandler();
+    this.findPersonApiHandler.setDynamoDbMapper(dynamoDbMapper);
+  }
+
+  @Test
+  public void handleRequest() {
+    findPersonApiHandler.handleRequest(apiGatewayProxyRequestEvent(), mock(Context.class));
+    verify(dynamoDbMapper, times(1)).load(Person.class, "37e7a1fe-3544-473d-b764-18128f02d72d");
+  }
+
+  private APIGatewayProxyRequestEvent apiGatewayProxyRequestEvent() {
+    return new APIGatewayProxyRequestEvent()
+        .withPathParamters(Collections
+            .singletonMap("id", "37e7a1fe-3544-473d-b764-18128f02d72d"));
+  }
+}

serverless/src/test/java/com/illuwatar/serverless/baas/api/SavePersonApiHandlerTest.java

@@ -0,0 +1,78 @@
+package com.illuwatar.serverless.baas.api;
+
+import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper;
+import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent;
+import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyResponseEvent;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.iluwatar.serverless.baas.api.SavePersonApiHandler;
+import com.iluwatar.serverless.baas.model.Address;
+import com.iluwatar.serverless.baas.model.Person;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+
+import static org.mockito.Mockito.*;
+
+/**
+ * Created by dheeraj.mummar on 3/4/18.
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class SavePersonApiHandlerTest {
+
+  private SavePersonApiHandler savePersonApiHandler;
+
+  @Mock
+  private DynamoDBMapper dynamoDbMapper;
+
+  private ObjectMapper objectMapper = new ObjectMapper();
+
+  @Before
+  public void setUp() {
+    this.savePersonApiHandler = new SavePersonApiHandler();
+    this.savePersonApiHandler.setDynamoDbMapper(dynamoDbMapper);
+  }
+
+  @Test
+  public void handleRequestSavePersonSuccessful() throws JsonProcessingException {
+    Person person = newPerson();
+    APIGatewayProxyResponseEvent apiGatewayProxyResponseEvent =
+        this.savePersonApiHandler
+            .handleRequest(apiGatewayProxyRequestEvent(objectMapper.writeValueAsString(person)), mock(Context.class));
+    verify(dynamoDbMapper, times(1)).save(person);
+    Assert.assertNotNull(apiGatewayProxyResponseEvent);
+    Assert.assertEquals(new Integer(201), apiGatewayProxyResponseEvent.getStatusCode());
+  }
+
+  @Test
+  public void handleRequestSavePersonException() {
+    APIGatewayProxyResponseEvent apiGatewayProxyResponseEvent =
+        this.savePersonApiHandler
+            .handleRequest(apiGatewayProxyRequestEvent("invalid sample request"), mock(Context.class));
+    Assert.assertNotNull(apiGatewayProxyResponseEvent);
+    Assert.assertEquals(new Integer(400), apiGatewayProxyResponseEvent.getStatusCode());
+  }
+
+  private APIGatewayProxyRequestEvent apiGatewayProxyRequestEvent(String body) {
+    APIGatewayProxyRequestEvent apiGatewayProxyRequestEvent = new APIGatewayProxyRequestEvent();
+    return apiGatewayProxyRequestEvent.withBody(body);
+  }
+
+  private Person newPerson() {
+    Person person = new Person();
+    person.setFirstName("Thor");
+    person.setLastName("Odinson");
+    Address address = new Address();
+    address.setAddressLineOne("1 Odin ln");
+    address.setCity("Asgard");
+    address.setState("country of the Gods");
+    address.setZipCode("00001");
+    person.setAddress(address);
+
+    return person;
+  }
+}

serverless/src/test/java/com/iluwatar/serverless/faas/api/LambdaInfoApiHandlerTest.java

@@ -20,7 +20,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-package com.iluwatar.serverless.api;
+package com.iluwatar.serverless.faas.api;
 
 import com.amazonaws.services.lambda.runtime.Context;
 import org.junit.jupiter.api.Test;