Add TTL in epoch seconds

Author: vlbee

cdk/lib/__snapshots__/liveactivities.test.ts.snap

@@ -885,6 +885,10 @@ exports[`The LiveActivities stack matches the snapshot for CODE 1`] = `
             "Value": "CODE",
           },
         ],
+        "TimeToLiveSpecification": {
+          "AttributeName": "ttlInEpochSeconds",
+          "Enabled": true,
+        },
       },
       "Type": "AWS::DynamoDB::Table",
       "UpdateReplacePolicy": "Retain",

cdk/lib/liveactivities.ts

@@ -24,7 +24,9 @@ export class LiveActivities extends GuStack {
 			tableName: dynamoTableName,
 			partitionKey: { name: 'id', type: AttributeType.STRING },
 			billingMode: BillingMode.PAY_PER_REQUEST,
+      timeToLiveAttribute: "ttlInEpochSeconds"
 		});
+
 		Tags.of(dynamoTable).add('devx-backup-enabled', 'true');
 
 		const channelManagerDlq = new Queue(this, 'ChannelManagerDlq', {

liveactivities/src/main/scala/com/gu/liveactivities/models/LiveActivities.scala

@@ -61,8 +61,9 @@ case class LiveActivityMapping(
     data: Option[LiveActivityData],
     lastEventId: Option[String],
     lastEventAt: Option[ZonedDateTime],
-		createdAt: ZonedDateTime,
-    lastModifiedAt: ZonedDateTime
+    createdAt: ZonedDateTime,
+    lastModifiedAt: ZonedDateTime,
+    ttlInEpochSeconds: Option[Long] = None
 )
 
 object LiveActivityMapping {

liveactivities/src/main/scala/com/gu/liveactivities/service/LiveActivityChannelRepository.scala

@@ -59,6 +59,7 @@ class LiveActivityChannelRepository(client: DynamoDbAsyncClient, tableName: Stri
     eventData: Option[LiveActivityData],
   ): Future[Unit] = {
     val createdAt = ZonedDateTime.now()
+    val ttlEpochSeconds = createdAt.toEpochSecond + 14 * 24 * 3600 // 15=4 days from now
     val newItem = new LiveActivityMapping(
       id = id, 
       channelId = channelId, 
@@ -68,7 +69,8 @@ class LiveActivityChannelRepository(client: DynamoDbAsyncClient, tableName: Stri
       lastEventId = None,
       lastEventAt = None,
       createdAt = createdAt,
-      lastModifiedAt = createdAt
+      lastModifiedAt = createdAt,
+      ttlInEpochSeconds = Some(ttlEpochSeconds)
     )
     scanamo.exec {
         table.when(attributeNotExists(idKeyName)).put(newItem)