I am trying download a .rpm file from S3 and exract .rmp file using rpm-extract npm library. I am using sdk v2 and aws lambda. I am getting error while extracting the rmp files which is thrwon from here https://github.com/dowjones/rpm-extract/blob/master/src/gzUnzip.js#L15. I am not sure how the .rpm file in S3 bucket is compressed. But I am assuming that when I download the .rpm files from S3 and write to lambda /tmp folder, rpm file is getting compressed again. Is there a way I can directly download the file from S3 without reading and writing the content? I can’t use sdk V3. I am using Nodejs aws lambda to run the code. or is there any other way to extract .rpm files in javascript. Here is code –

const AWS = require('aws-sdk');
const fs = require('fs');
const rpmExtract = require('rpm-extract')

// Create an S3 instance
const s3 = new AWS.S3();


const downloadFileFromS3 = async (bucket, key) => {
    const tempFilePath = '/tmp/content.rmp'; // Store in /tmp directory
    console.log('Temp file path set:', tempFilePath);

    const params = {
        Bucket: bucket,
        Key: key
    };
    console.log('Params set for S3 getObject:', params);

    console.log('Downloading file from S3...');
    try {
        const data = await s3.getObject(params).promise();

        console.log('Writing file to disk...');
        fs.writeFileSync(tempFilePath, data.Body);

        console.log('File downloaded successfully:', tempFilePath);

        return tempFilePath;
    } catch (error) {
        console.error('Error downloading file from S3:', error);
        throw error;
    }
};

async function getCertsFromRpm(s3Bucket, s3Key) {
    try {
        console.log("Inside getCertsFromRpm function");
        const rpmFile = await downloadFileFromS3(s3Bucket, s3Key);
        console.log("RPM file downloaded successfully:", rpmFile);

        const files = await rpmExtract.default(rpmFile);
        console.log("RPM file extracted successfully. Total files:", files.length);

        // Filter out symbolic links and select only .pem files
        const pemFiles = files
            .filter((file) => !file.linkname && file.path.endsWith('.pem'))
            .map((file) => file.data.toString());

        console.log("Filtered PEM files:", pemFiles);
        return pemFiles;
    } catch (err) {
        console.error('Error extracting certificates from RPM:', err);
        return [];
    }
}

module.exports = {
    getCertsFromRpm
}

I tries using file stream too

const AWS = require('aws-sdk');
const fs = require('fs');
const rpmExtract = require('rpm-extract')
 
// Create an S3 instance
const s3 = new AWS.S3();
 
 
const downloadFileFromS3 = (bucket, key) => {
    const tempFilePath = '/tmp/content.rpm'; // Store in /tmp directory
    console.log('Temp file path set:', tempFilePath);
 
    const params = {
        Bucket: bucket,
        Key: key
    };
    console.log('Params set for S3 getObject:', params);
 
    console.log('Downloading file from S3...');
 
    return new Promise((resolve, reject) => {
        const fileStream = fs.createWriteStream(tempFilePath);
        console.log('Writable file stream created.');
 
        const s3Stream = s3.getObject(params).createReadStream();
        console.log('S3 read stream created.');
 
        s3Stream.on('error', (err) => {
            console.error('Error retrieving file from S3:', err);
            reject(err);
        });
 
        fileStream.on('error', (err) => {
            console.error('Error writing file to disk:', err);
            reject(err);
        });
 
        fileStream.on('close', () => {
            console.log('File downloaded successfully:', tempFilePath);
            resolve(tempFilePath);
        });
        console.log('Close listener added for file stream.');
 
        s3Stream.on('data', (data) => {
            console.log('Downloading data from S3...');
            console.log('Data received:', data.toString()); // Log the data being written
        });
        console.log('Data listener added for S3 stream.');
 
        s3Stream.on('end', () => {
            console.log('S3 download stream ended.');
        });
        console.log('End listener added for S3 stream.');
 
        s3Stream.pipe(fileStream);
        console.log('Piped S3 stream to file stream.');
    });
};
 
async function getCertsFromRpm(s3Bucket, s3Key) {
    try {
        console.log("Inside getCertsFromRpm function");
        const rpmFile = await downloadFileFromS3(s3Bucket, s3Key);
        console.log("RPM file downloaded successfully:", rpmFile);
 
        const files = await rpmExtract(rpmFile);
        console.log("RPM file extracted successfully. Total files:", files.length);
 
        // Filter out symbolic links and select only .pem files
        const pemFiles = files
            .filter((file) => !file.linkname && file.path.endsWith('.pem'))
            .map((file) => file.data.toString());
 
        console.log("Filtered PEM files:", pemFiles);
        return pemFiles;
    } catch (err) {
        console.error('Error extracting certificates from RPM:', err);
        return [];
    }
}
 
module.exports = {
    getCertsFromRpm
}