Deploy price tracker on a 1 hour schedule

immersion_tracker_api/infra/main.tf

@@ -129,7 +129,6 @@ data "aws_iam_policy_document" "lambda_dynamodb_allow_policy_document" {
     actions = [
       "dynamodb:PutItem",
       "dynamodb:UpdateItem",
-      "dynamodb:DeleteItem",
       "dynamodb:BatchWriteItem",
       "dynamodb:GetItem",
       "dynamodb:BatchGetItem",

lib/notifications/src/main/java/com/jordansimsmith/lib/notifications/SnsNotificationPublisher.java

@@ -1,6 +1,8 @@
 package com.jordansimsmith.lib.notifications;
 
+import com.google.common.collect.Iterables;
 import software.amazon.awssdk.services.sns.SnsClient;
+import software.amazon.awssdk.services.sns.model.ListTopicsRequest;
 import software.amazon.awssdk.services.sns.model.PublishRequest;
 
 public class SnsNotificationPublisher implements NotificationPublisher {
@@ -12,8 +14,16 @@ public SnsNotificationPublisher(SnsClient snsClient) {
 
   @Override
   public void publish(String topic, String subject, String message) {
-    var req = PublishRequest.builder().topicArn(topic).subject(subject).message(message).build();
+    var topicArn = getTopicArn(topic);
+    var req = PublishRequest.builder().topicArn(topicArn).subject(subject).message(message).build();
 
     snsClient.publish(req);
   }
+
+  private String getTopicArn(String topic) {
+    var req = ListTopicsRequest.builder().build();
+    var res = snsClient.listTopics(req);
+    var topics = res.topics().stream().filter(t -> t.topicArn().endsWith(":" + topic)).toList();
+    return Iterables.getOnlyElement(topics).topicArn();
+  }
 }

price_tracker_api/BUILD.bazel

@@ -36,6 +36,8 @@ java_binary(
         ":lib",
         "//lib/notifications:lib",
         "//lib/time:lib",
+        "@maven//:ch_qos_logback_logback_classic",
+        "@maven//:ch_qos_logback_logback_core",
         "@maven//:com_amazonaws_aws_lambda_java_core",
         "@maven//:com_amazonaws_aws_lambda_java_events",
         "@maven//:com_google_code_findbugs_jsr305",

price_tracker_api/infra/main.tf

@@ -31,6 +31,8 @@ locals {
       handler = "com.jordansimsmith.pricetracker.UpdatePricesHandler"
     }
   }
+
+  subscriptions = ["[email protected]"]
 }
 
 data "aws_iam_policy_document" "lambda_sts_allow_policy_document" {
@@ -57,6 +59,112 @@ resource "aws_iam_role_policy_attachment" "lambda_basic" {
   policy_arn = "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
 }
 
+resource "aws_dynamodb_table" "price_tracker" {
+  name         = "price_tracker"
+  billing_mode = "PAY_PER_REQUEST"
+  hash_key     = "pk"
+  range_key    = "sk"
+
+  attribute {
+    name = "pk"
+    type = "S"
+  }
+
+  attribute {
+    name = "sk"
+    type = "S"
+  }
+
+  point_in_time_recovery {
+    enabled = true
+  }
+
+  deletion_protection_enabled = true
+
+  tags = local.tags
+}
+
+data "aws_iam_policy_document" "lambda_dynamodb" {
+  statement {
+    effect = "Allow"
+
+    resources = [
+      aws_dynamodb_table.price_tracker.arn
+    ]
+
+    actions = [
+      "dynamodb:PutItem",
+      "dynamodb:UpdateItem",
+      "dynamodb:BatchWriteItem",
+      "dynamodb:GetItem",
+      "dynamodb:BatchGetItem",
+      "dynamodb:Scan",
+      "dynamodb:Query",
+      "dynamodb:ConditionCheckItem",
+    ]
+  }
+}
+
+resource "aws_iam_policy" "lambda_dynamodb" {
+  name   = "${local.application_id}_lambda_dynamodb"
+  policy = data.aws_iam_policy_document.lambda_dynamodb.json
+  tags   = local.tags
+}
+
+resource "aws_iam_role_policy_attachment" "lambda_dynamodb" {
+  role       = aws_iam_role.lambda_role.name
+  policy_arn = aws_iam_policy.lambda_dynamodb.arn
+}
+
+resource "aws_sns_topic" "price_updates" {
+  name = "${local.application_id}_price_updates"
+}
+
+resource "aws_sns_topic_subscription" "price_updates" {
+  for_each  = toset(local.subscriptions)
+  topic_arn = aws_sns_topic.price_updates.arn
+  protocol  = "email"
+  endpoint  = each.value
+}
+
+data "aws_iam_policy_document" "lambda_sns" {
+  statement {
+    effect = "Allow"
+
+    resources = [
+      aws_sns_topic.price_updates.arn,
+    ]
+
+    actions = [
+      "SNS:Publish",
+      "SNS:GetTopicAttributes",
+    ]
+  }
+
+  statement {
+    effect = "Allow"
+
+    resources = [
+      "*"
+    ]
+
+    actions = [
+      "SNS:ListTopics"
+    ]
+  }
+}
+
+resource "aws_iam_policy" "lambda_sns" {
+  name   = "${local.application_id}_lambda_sns"
+  policy = data.aws_iam_policy_document.lambda_sns.json
+  tags   = local.tags
+}
+
+resource "aws_iam_role_policy_attachment" "lambda_sns" {
+  role       = aws_iam_role.lambda_role.name
+  policy_arn = aws_iam_policy.lambda_sns.arn
+}
+
 data "external" "handler_location" {
   for_each = local.lambdas
 
@@ -82,7 +190,26 @@ resource "aws_lambda_function" "lambda" {
   source_code_hash = data.local_file.handler_file[each.key].content_base64sha256
   handler          = each.value.handler
   runtime          = "java17"
-  memory_size      = 512
-  timeout          = 10
+  memory_size      = 1024
+  timeout          = 30
   tags             = local.tags
 }
+
+resource "aws_cloudwatch_event_rule" "trigger" {
+  name                = "${local.application_id}_trigger"
+  schedule_expression = "rate(1 hour)"
+}
+
+resource "aws_cloudwatch_event_target" "trigger" {
+  rule      = aws_cloudwatch_event_rule.trigger.name
+  target_id = "lambda"
+  arn       = aws_lambda_function.lambda["update_prices"].arn
+}
+
+resource "aws_lambda_permission" "cloudwatch_trigger" {
+  statement_id  = "AllowExecutionFromCloudWatch"
+  action        = "lambda:InvokeFunction"
+  function_name = aws_lambda_function.lambda["update_prices"].function_name
+  principal     = "events.amazonaws.com"
+  source_arn    = aws_cloudwatch_event_rule.trigger.arn
+}

price_tracker_api/src/main/java/com/jordansimsmith/pricetracker/ProductsFactoryImpl.java

@@ -41,6 +41,14 @@ public List<Product> findChemistWarehouseProducts() {
         new Product(
             URI.create(
                 "https://www.chemistwarehouse.co.nz/buy/111309/inc-high-protein-bar-peanut-butter-fudge-100g"),
-            "Chemist Warehouse - INC High Protein Bar Peanut Butter Fudge 100g"));
+            "Chemist Warehouse - INC High Protein Bar Peanut Butter Fudge 100g"),
+        new Product(
+            URI.create(
+                "https://www.chemistwarehouse.co.nz/buy/120088/musashi-electrolytes-blue-raspberry-300g"),
+            "Musashi Electrolytes Blue Raspberry 300g"),
+        new Product(
+            URI.create(
+                "https://www.chemistwarehouse.co.nz/buy/101969/musashi-electrolytes-watermelon-300g"),
+            "Musashi Electrolytes Watermelon 300g"));
   }
 }

price_tracker_api/src/main/java/com/jordansimsmith/pricetracker/UpdatePricesHandler.java

@@ -15,7 +15,7 @@
 import software.amazon.awssdk.enhanced.dynamodb.model.QueryEnhancedRequest;
 
 public class UpdatePricesHandler implements RequestHandler<ScheduledEvent, Void> {
-  @VisibleForTesting static final String TOPIC = "my topic";
+  @VisibleForTesting static final String TOPIC = "price_tracker_api_price_updates";
 
   private final Clock clock;
   private final NotificationPublisher notificationPublisher;
@@ -93,7 +93,7 @@ private Void doHandleRequest(ScheduledEvent event, Context context) throws Excep
           priceChanges.size() == 1
               ? "1 price updated"
               : "%d prices updated".formatted(priceChanges.size());
-      var message = new StringJoiner("\\n");
+      var message = new StringJoiner("\r\n\r\n");
       for (var priceChange : priceChanges) {
         var line =
             "%s $%.2f -> $%.2f %s"