fetching files from S3 bucket in AWS

aws_connect.js

const aws = require("@aws-sdk/client-s3");

//
// Throws an error if the any required environment variables are missing.
//

if (!process.env.AWS_ACCESS_KEY_ID) {
  throw new Error(
    "Please specify the name of an AWS storage account in environment variable AWS_ACCESS_KEY_ID."
  );
}

if (!process.env.AWS_SECRET_ACCESS_KEY) {
  throw new Error(
    "Please specify the access key to an AWs storage account in environment variable AWS_SECRET_ACCESS_KEY."
  );
}

if (!process.env.AWS_REGION) {
  throw new Error(
    "Please specify the access region for AWs storage account in environment variable AWS_REGION."
  );
}
//if you leave this blank, it will default to the local config file
const s3Client = new aws.S3Client({
  region: process.env.AWS_REGION,
  accessKeyId: process.env.AWS_ACCESS_KEY_ID,
  secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
});

const getObjectParams = {
  Bucket: "video-storage-project",
  Key: "SampleVideo_1280x720_1mb.mp4",
};

async function listBuckets() {
  try {
    const command = new aws.ListBucketsCommand({});

    const { Buckets } = await s3Client.send(command);
    console.log("List Buckets: ");
    console.log(Buckets.map((bucket) => bucket.Name).join("\n"));
    console.log("---end of buckets---");
    return Buckets;
  } catch (e) {
    console.error("error at read buckets: ", e);
  }
}

async function fetchFileFromS3() {
  try {
    const { Body, ContentLength } = await s3Client.send(
      new aws.GetObjectCommand(getObjectParams)
    );
    return { Body, ContentLength };
  } catch (e) {
    console.error("error fetching file from s3");
    console.error(e);
  }
}

module.exports = { fetchFileFromS3, listBuckets };

index.js

const express = require("express");
const { fetchFileFromS3, listBuckets } = require("./aws_connect");
const multer = require("multer");
//
// Throws an error if the any required environment variables are missing.
//

if (!process.env.PORT) {
  throw new Error(
    "Please specify the port number for the HTTP server with the environment variable PORT."
  );
}

const PORT = process.env.PORT;

console.log(
  `Serving videos from AWS access key id ${process.env.AWS_ACCESS_KEY_ID}.`
);

const app = express();

//
// Registers a HTTP GET route to retrieve videos from storage.
//
app.get("/video", async (req, res) => {
  const videoPath = req.route.path;
  console.log("Serving file from ", videoPath);
  const videoStream = await fetchFileFromS3();

  res.writeHead(200, {
    "Content-Type": "video/mp4",
    "Content-Length": videoStream.ContentLength,
  });
  videoStream.Body.pipe(res);
});

// http://localhost:3000/video? path=SampleVideo_1280x720_1mb.mp4. =

app.get("/listBuckets", async (req, res) => {
  const buckets = await listBuckets();
  res.status(200).send("Buckets retreived", JSON.stringify(buckets));
});

// Set up multer for file uploads
const upload = multer({ dest: "uploads/" });

// Define a route to handle file uploads
app.post("/upload", upload.single("file"), async (req, res) => {
  const fileStream = Readable.from(req.file.buffer);

  const params = {
    Bucket: "YOUR_S3_BUCKET_NAME",
    Key: req.file.originalname,
    Body: fileStream,
  };

  try {
    await s3Client.send(new PutObjectCommand(params));
    console.log("File uploaded successfully");
    res.status(200).send("File uploaded");
  } catch (err) {
    console.error(err);
    res.status(500).send("Failed to upload file");
  }
});

//
// Starts the HTTP server.
//
app.listen(PORT, () => {
  console.log(`Microservice online`);
});