⭐ feat: Upgrade to asynchronous event bus with retry queue and backoff strategy (#290)

## Description
<!-- Briefly describe the purpose and scope of your changes -->


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
- Introduced a retry and dead-letter queue system for more robust event
processing.
- Added a retry handler for processing failed Lambda invocations with
exponential backoff.
- Enhanced event handling to support retry logic and improved error
management.

- **Refactor**
- Replaced SQS-based library event processing with an event bus-based
approach.
- Updated event names and structure for improved clarity and
consistency.
  - Removed legacy library queue and related infrastructure.

- **Chores**
  - Updated dependencies to include the AWS Lambda client.
  - Cleaned up unused code and removed deprecated event handling logic.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

infra/api.ts

@@ -4,7 +4,6 @@ import { domain } from "./dns";
 import { secret } from "./secret";
 import { cluster } from "./cluster";
 import { postgres } from "./postgres";
-import { libraryQueue } from "./steam";
 
 export const apiService = new sst.aws.Service("Api", {
     cluster,
@@ -14,7 +13,6 @@ export const apiService = new sst.aws.Service("Api", {
         bus,
         auth,
         postgres,
-        libraryQueue,
         secret.SteamApiKey,
         secret.PolarSecret,
         secret.PolarWebhookSecret,

infra/bus.ts

@@ -1,12 +1,15 @@
 import { vpc } from "./vpc";
 import { secret } from "./secret";
-// import { email } from "./email";
 import { storage } from "./storage";
 import { postgres } from "./postgres";
 
+export const dlq = new sst.aws.Queue("Dlq");
+
+export const retryQueue = new sst.aws.Queue("RetryQueue");
+
 export const bus = new sst.aws.Bus("Bus");
 
-bus.subscribe("Event", {
+export const eventSub = bus.subscribe("Event", {
   vpc,
   handler: "packages/functions/src/events/index.handler",
   link: [
@@ -14,22 +17,54 @@ bus.subscribe("Event", {
     bus,
     storage,
     postgres,
+    retryQueue,
     secret.PolarSecret,
     secret.SteamApiKey
   ],
-  timeout: "10 minutes",
+  environment: {
+    RETRIES: "2",
+  },
   memory: "3002 MB",// For faster processing of large(r) images
+  timeout: "10 minutes",
+});
+
+new aws.lambda.FunctionEventInvokeConfig("EventConfig", {
+  functionName: $resolve([eventSub.nodes.function.name]).apply(
+    ([name]) => name,
+  ),
+  maximumRetryAttempts: 1,
+  destinationConfig: {
+    onFailure: {
+      destination: retryQueue.arn,
+    },
+  },
+});
+
+retryQueue.subscribe({
+  vpc,
+  handler: "packages/functions/src/queues/retry.handler",
+  timeout: "30 seconds",
+  environment: {
+    RETRIER_QUEUE_URL: retryQueue.url,
+  },
+  link: [
+    dlq,
+    retryQueue,
+    eventSub.nodes.function,
+  ],
   permissions: [
     {
-      actions: ["ses:SendEmail","sqs:SendMessage"],
-      resources: ["*"],
+      actions: ["lambda:GetFunction", "lambda:InvokeFunction"],
+      resources: [
+        $interpolate`arn:aws:lambda:${aws.getRegionOutput().name}:${aws.getCallerIdentityOutput().accountId}:function:*`,
+      ],
     },
   ],
-  // transform: {
-  //   function: {
-  //     deadLetterConfig: {
-  //       targetArn: EventDlq.arn,
-  //     },
-  //   },
-  // },
+  transform: {
+    function: {
+      deadLetterConfig: {
+        targetArn: dlq.arn,
+      },
+    },
+  },
 });

infra/steam.ts

@@ -1,29 +0,0 @@
-import { bus } from "./bus";
-import { vpc } from "./vpc";
-import { secret } from "./secret";
-import { postgres } from "./postgres";
-
-export const libraryDlq = new sst.aws.Queue("LibraryDLQ");
-
-export const libraryQueue = new sst.aws.Queue("LibraryQueue", {
-    dlq: libraryDlq.arn,
-    visibilityTimeout: "5 minutes",
-});
-
-libraryQueue.subscribe({
-    vpc,
-    memory: "3002 MB",
-    timeout: "5 minutes",
-    handler: "packages/functions/src/queues/library.handler",
-    link: [
-        bus,
-        postgres,
-        secret.SteamApiKey
-    ],
-    permissions: [
-        {
-            actions: ["sqs:SendMessage"],
-            resources: ["*"],
-        },
-    ],
-});