Adding file to create presigned URL from s3 bucket object.

Author: Taylor Grafft

api/presignedURL.js

@@ -0,0 +1,53 @@
+const AWS = require('aws-sdk');
+const fs = require('fs');
+const path = require('path');
+
+// Read the AWS secret access key from the aws.key file
+const secretAccessKey = fs.readFileSync(path.join(__dirname, 'config', 'aws.key'), 'utf8').trim();
+
+// Configure AWS with credentials and region
+const s3 = new AWS.S3({
+    accessKeyId: 'FQAQ3RWRSCR6POF2NCQC',
+    secretAccessKey: secretAccessKey,
+    endpoint: 'https://s3.msi.umn.edu',
+    s3ForcePathStyle: true,
+    region: 'us-east-1'
+});
+
+// Function to list objects in a bucket
+const listObjects = async (bucketName) => {
+    const params = {
+        Bucket: bucketName
+    };
+
+    try {
+        const data = await s3.listObjectsV2(params).promise();
+        console.log('Objects in bucket:', data.Contents);
+
+        // Filter the objects to only show zarr files
+        // const zarrFiles = data.Contents.filter(obj => obj.Key.endsWith('.zarr'));
+        // console.log('Zarr files in bucket:', zarrFiles);
+    } catch (err) {
+        console.error('Error listing objects:', err);
+    }
+};
+
+// Function to generate a presigned URL for an S3 object
+const generatePresignedURL = (bucketName, key, expiresIn) => {
+    const params = {
+        Bucket: bucketName,
+        Key: key,
+        Expires: expiresIn
+    };
+
+    return s3.getSignedUrl('getObject', params);
+};
+
+const bucketName = 'midb-cmc-nonhuman';
+const key = 'PS-OCT/KQRH/3D Tiles/A1A2/slice_155_tile_33_CH1.mat';
+const expiresIn = 60 * 10; // URL expires in 10 minutes
+
+const url = generatePresignedURL(bucketName, key, expiresIn);
+console.log('Presigned URL:', url);
+
+// listObjects(bucketName);