Add AWS S3 integration with presigned URL generation and compatibility flags

package.json

@@ -12,5 +12,9 @@
 		"@cloudflare/vitest-pool-workers": "^0.7.5",
 		"vitest": "~3.0.7",
 		"wrangler": "^3.112.0"
+	},
+	"dependencies": {
+		"@aws-sdk/client-s3": "^3.758.0",
+		"@aws-sdk/s3-request-presigner": "^3.758.0"
 	}
 }

src/index.js

@@ -7,9 +7,57 @@
  *
  * Learn more at https://developers.cloudflare.com/workers/
  */
+import { S3Client, PutObjectCommand } from "@aws-sdk/client-s3";
+import { getSignedUrl } from "@aws-sdk/s3-request-presigner";
 
 export default {
 	async fetch(request, env, ctx) {
-		return new Response('Hello World!');
+		const url = new URL(request.url);
+		const key = url.pathname;
+		
+		if (url.hostname !== '127.0.0.1' && url.protocol === 'http:') {
+			return new Response(null, { status: 301, headers: {
+				Location: url.toString().replace(/^(http:)/, 'https:')
+			}});
+		}
+		
+		let endpoint, accessKeyId, secretAccessKey, region, bucket;
+		switch (url.searchParams.get('backend')) {
+			case 'r2':
+				endpoint = env.R2_ENDPOINT;
+				accessKeyId = env.R2_ACCESS_KEY_ID;
+				secretAccessKey = env.R2_SECRET_ACCESS_KEY;
+				region = 'auto';
+				bucket = env.R2_BUCKET;
+				break;
+			case 'cos-global':
+				endpoint = env.COS_GLOBAL_ENDPOINT;
+				accessKeyId = env.COS_GLOBAL_ACCESS_KEY_ID;
+				secretAccessKey = env.COS_GLOBAL_SECRET_ACCESS_KEY;
+				region = 'accelerate';
+				bucket = env.COS_GLOBAL_BUCKET;
+				break;
+			case 'cos-cn':
+				endpoint = env.COS_CN_ENDPOINT;
+				accessKeyId = env.COS_CN_ACCESS_KEY_ID;
+				secretAccessKey = env.COS_CN_SECRET_ACCESS_KEY;
+				region = env.COS_CN_REGION;
+				bucket = env.COS_CN_BUCKET;
+				break;
+			default:
+				return new Response('Invalid backend', { status: 400 });
+		}
+		
+		const client = new S3Client({
+			endpoint,
+			credentials: { accessKeyId, secretAccessKey },
+			region,
+			maxRetries: 3,
+			signatureVersion: 'v4',
+		});
+		
+		const command = new PutObjectCommand({ Bucket: bucket, Key: key });
+  		const signedUrl = await getSignedUrl(client, command, { expiresIn: 24*60*60 });
+		return new Response(signedUrl);
 	},
-};
+};

wrangler.jsonc

@@ -6,6 +6,9 @@
 	"$schema": "node_modules/wrangler/config-schema.json",
 	"name": "s3-presigned",
 	"main": "src/index.js",
+	"compatibility_flags": [
+    	"nodejs_compat"
+  	],
 	"compatibility_date": "2025-03-10",
 	"observability": {
 		"enabled": true