rename db service class + fix config files + readme fix

Author: Anca

README.md

@@ -67,7 +67,7 @@ needs to be created with the following policies:
 - AWSLambda_FullAccess
 - AmazonDynamoDBFullAccess
 
-We will be using the user's credentials and export them as temporary environment variable with the
+We will be using the user's credentials and export them as temporary environment variables with the
 `export` (`set` on Windows) command:
 
 ```
@@ -172,7 +172,7 @@ Usage: terraform [global options] <subcommand> [args]
 ```
 
 From here on, it's smooth sailing, the same as before. Switch to `setup/tflocal` folder, the files are 
-identical as the ones in `setup/terraform`, but for the newly generated state files, it is a good idea
+identical to the ones in `setup/terraform`, but for the newly generated state files, it is a good idea
 to separate these "workspaces":
 
 ```
@@ -192,7 +192,7 @@ root folder):
 $ mvn spring-boot:run -Dspring-boot.run.profiles=dev
 ```
 
-Go back to `localhost:3000` and a new list will be available, and notice that the functionalities of
+Go back to `localhost:3000` and a new list will be available; notice that the functionalities of
 the application have not changed.
 
 There you have it, smooth transition from AWS to Localstack, with no code change. 👍🏻

docker-compose.yml

@@ -2,15 +2,10 @@ version: "3.9"
 
 services:
   localstack:
-    image: localstack/localstack
-    container_name: localstack
+    image: localstack/localstack  # name and tag of LocalStack Docker image to use
+    container_name: localstack  # the main docker container name
     ports:
       - "127.0.0.1:4566:4566"            # LocalStack Gateway
-      - "127.0.0.1:4510-4559:4510-4559"  # external services port range
     environment:
-      - DEFAULT_REGION=eu-central-1 # where the localstack mocks will be running
-      - DATA_DIR=/tmp/localstack/data
       - PORT_WEB_UI=9000
-      - LAMBDA_EXECUTOR=local
-      - DOCKER_HOST=unix:///var/run/docker.sock
-      - START_WEB=1
+      - LAMBDA_EXECUTOR=local  # the lambda code is executed directly in the context of LocalStack itself

setup/terraform/main.tf

@@ -1,3 +1,6 @@
+
+# declares the provider it will be using (AWS) and the minimum
+# version of the provider required to run the script
 terraform {
   required_providers {
     aws = {
@@ -10,8 +13,10 @@ provider "aws" {
   region = "eu-central-1"
 }
 
+# S3 bucket, named "shipment-picture-bucket", which is set to be destroyed even if it
+# has non-empty contents, and sets the ACL to be private
 resource "aws_s3_bucket" "shipment_picture_bucket" {
-  bucket = "shipment-picture-bucket"
+  bucket        = "shipment-picture-bucket"
   force_destroy = true
   lifecycle {
     prevent_destroy = false
@@ -24,6 +29,8 @@ resource "aws_s3_bucket_acl" "shipment_picture_bucket_acl" {
   acl    = "private"
 }
 
+# dynamoDB table is created, with a primary key "shipmentId" and
+# enables server-side encryption
 resource "aws_dynamodb_table" "shipment" {
   name           = "shipment"
   read_capacity  = 10
@@ -42,16 +49,17 @@ resource "aws_dynamodb_table" "shipment" {
   stream_view_type = "NEW_AND_OLD_IMAGES"
 }
 
+# populates table with sample data from file
 resource "aws_dynamodb_table_item" "shipment" {
   for_each   = local.tf_data
   table_name = aws_dynamodb_table.shipment.name
   hash_key   = "shipmentId"
   item       = jsonencode(each.value)
 }
 
-
+# the bucket used for storing the lambda jar
 resource "aws_s3_bucket" "lambda_code_bucket" {
-  bucket = "shipment-picture-lambda-validator-bucket"
+  bucket        = "shipment-picture-lambda-validator-bucket"
   force_destroy = true
   lifecycle {
     prevent_destroy = false
@@ -60,15 +68,19 @@ resource "aws_s3_bucket" "lambda_code_bucket" {
 
 resource "aws_s3_bucket_acl" "lambda_code_bucket_acl" {
   bucket = aws_s3_bucket.lambda_code_bucket.id
-  acl = "private"
+  acl    = "private"
 }
 
+# bucket object with lambda code
 resource "aws_s3_bucket_object" "lambda_code" {
   source = "../../shipment-picture-lambda-validator/target/shipment-picture-lambda-validator-1.0-SNAPSHOT.jar"
   bucket = aws_s3_bucket.lambda_code_bucket.id
   key    = "shipment-picture-lambda-validator-1.0-SNAPSHOT.jar"
 }
 
+# creates lambda using the JAR file uploaded to the S3 bucket.
+# the function is set up with a java 11 runtime, with a specified IAM role,
+# memory of 512mb, timeout of 15s, and environment variable
 resource "aws_lambda_function" "shipment_picture_lambda_validator" {
   function_name = "shipment-picture-lambda-validator"
   handler       = "dev.ancaghenade.shipmentpicturelambdavalidator.ServiceHandler::handleRequest"
@@ -85,6 +97,9 @@ resource "aws_lambda_function" "shipment_picture_lambda_validator" {
   }
 }
 
+
+# notification for "shipment-picture-bucket" S3 bucket,
+# so that the lambda function will be triggered when a new object is created in the bucket.
 resource "aws_s3_bucket_notification" "demo_bucket_notification" {
   bucket = aws_s3_bucket.shipment_picture_bucket.id
   lambda_function {
@@ -101,6 +116,8 @@ resource "aws_lambda_permission" "s3_lambda_exec_permission" {
   source_arn    = aws_s3_bucket.shipment_picture_bucket.arn
 }
 
+# IAM role with a policy that allows it to assume the role of a lambda function
+# the role is attached to the Lambda function
 resource "aws_iam_role" "lambda_exec" {
   name = "lambda_exec_role"
 
@@ -120,11 +137,14 @@ resource "aws_iam_role" "lambda_exec" {
 EOF
 }
 
+# used to attach the AmazonS3FullAccess policy to the IAM role lambda_exec
 resource "aws_iam_role_policy_attachment" "lambda_exec_policy" {
   policy_arn = "arn:aws:iam::aws:policy/AmazonS3FullAccess"
   role       = aws_iam_role.lambda_exec.name
 }
 
+# used to create a custom IAM policy
+# & give permission to the lambda to interract with the S3 and cloudwatch logs
 resource "aws_iam_role_policy" "lambda_exec_policy" {
   name = "lambda_exec_policy"
   role = aws_iam_role.lambda_exec.id

…tdemo/repository/ShipmentRepository.java …listdemo/repository/DynamoDBService.javasrc/main/java/dev/ancaghenade/shipmentlistdemo/repository/ShipmentRepository.java renamed to src/main/java/dev/ancaghenade/shipmentlistdemo/repository/DynamoDBService.java src/main/java/dev/ancaghenade/shipmentlistdemo/repository/ShipmentRepository.java renamed to src/main/java/dev/ancaghenade/shipmentlistdemo/repository/DynamoDBService.java

@@ -13,12 +13,12 @@
 import org.springframework.stereotype.Repository;
 
 @Repository
-public class ShipmentRepository {
+public class DynamoDBService {
 
   private final DynamoDBMapper dynamoDBMapper;
 
   @Autowired
-  public ShipmentRepository(DynamoDBMapper dynamoDBMapper) {
+  public DynamoDBService(DynamoDBMapper dynamoDBMapper) {
     this.dynamoDBMapper = dynamoDBMapper;
   }
 

src/main/java/dev/ancaghenade/shipmentlistdemo/service/ShipmentService.java

@@ -6,7 +6,7 @@
 import dev.ancaghenade.shipmentlistdemo.buckets.BucketName;
 import dev.ancaghenade.shipmentlistdemo.entity.Shipment;
 import dev.ancaghenade.shipmentlistdemo.repository.S3StorageService;
-import dev.ancaghenade.shipmentlistdemo.repository.ShipmentRepository;
+import dev.ancaghenade.shipmentlistdemo.repository.DynamoDBService;
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
@@ -23,26 +23,26 @@
 public class ShipmentService {
 
 
-  private final ShipmentRepository shipmentRepository;
+  private final DynamoDBService dynamoDBService;
   private final S3StorageService s3StorageService;
 
 
   @Autowired
-  public ShipmentService(ShipmentRepository shipmentRepository, S3StorageService s3StorageService) {
-    this.shipmentRepository = shipmentRepository;
+  public ShipmentService(DynamoDBService dynamoDBService, S3StorageService s3StorageService) {
+    this.dynamoDBService = dynamoDBService;
     this.s3StorageService = s3StorageService;
   }
 
   public List<Shipment> getAllShipments() {
-    return shipmentRepository.getAllShipments();
+    return dynamoDBService.getAllShipments();
   }
 
   public String deleteShipment(String shipmentId) {
-   return shipmentRepository.delete(shipmentId);
+   return dynamoDBService.delete(shipmentId);
   }
 
   public Shipment saveShipment(Shipment shipment) {
-    return shipmentRepository.upsert(shipment);
+    return dynamoDBService.upsert(shipment);
   }
 
   public void uploadShipmentImage(String shipmentId, MultipartFile file) {
@@ -63,12 +63,12 @@ public void uploadShipmentImage(String shipmentId, MultipartFile file) {
       throw new IllegalStateException(e);
     }
     shipment.setImageLink(fileName);
-    shipmentRepository.upsert(shipment);
+    dynamoDBService.upsert(shipment);
   }
 
 
   public byte[] downloadShipmentImage(String shipmentId) {
-    Shipment shipment = shipmentRepository.getShipment(shipmentId).stream()
+    Shipment shipment = dynamoDBService.getShipment(shipmentId).stream()
         .findFirst()
         .orElseThrow(
             () -> new IllegalStateException(format("Shipment %s was not found.", shipmentId)));
@@ -93,7 +93,7 @@ private Map<String, String> getMetadata(MultipartFile file) {
   }
 
   private Shipment getShipment(String shipmentId) {
-    return shipmentRepository.getShipment(shipmentId).stream()
+    return dynamoDBService.getShipment(shipmentId).stream()
         .findFirst()
         .orElseThrow(
             () -> new IllegalStateException(format("Shipment %s was not found.", shipmentId)));

src/main/resources/application-dev.yml

@@ -6,5 +6,5 @@ aws:
   s3:
     endpoint: https://s3.localhost.localstack.cloud:4566/
   dynamodb:
-    endpoint: https://dynamodb.localhost.localstack.cloud:4566/
+    endpoint: https://localhost.localstack.cloud:4566/
   region: eu-central-1

src/main/resources/application-prod.yml

@@ -1,4 +1,3 @@
-
 aws:
   credentials:
     access-key: ${AWS_ACCESS_KEY_ID}