Issue
I have a zip file in S3 that contains several txt files and an image.
I am needing to grab that file from S3 and then unzip all of the files with their original filenames into the tmp directory in lambda using node.js
I am not super familiar with node and while the S3 part of getting the file works fine, I frankensteined the zip part together from the interwebs and was wondering if someone could help me get it right.
const zlib = require('zlib');
const fs = require('fs');
try {
const s3Object = await s3
.getObject({
Bucket: 'mybucket',
Key: `zip/${myzipfilename}`
})
.promise();
console.log("s3 zip fetched");
// write file to tmp
writeFileSync(`/tmp/${myzipfilename}`, s3Object.Body);
//unzip files
const fileContents = fs.createReadStream(`/tmp/${myzipfilename}`);
//I am quite sure this part is incorrect and is currently giving me an error
const writeStream = fs.createWriteStream(`./tmp/${filename.slice(0, -3)}`);
const unzip = zlib.createGunzip();
fileContents.pipe(unzip).pipe(writeStream);
}
End result within the lambda tmp directory would be something like:
/tmp/myoriginaltxtfilename.txt
/tmp/myoriginaltxtfilename2.txt
/tmp/myoriginaltxtfilename3.txt
/tmp/myoriginalimagefilename.png
I don't need to rezip anything.
Solution
You have a couple of issues in your code. First of all, at this line:
const writeStream = fs.createWriteStream(`./tmp/${filename.slice(0, -3)}`);
filename is not defined.
Second, you're using nodejs zlib to extract a .zip file which contains multiple files which won't work. zlib module is only for streams and buffers that represent singular resources not zip archives. You could use node-stream-zip instead.
Let's say you've successfully downloaded the zip file from S3 and saved in /tmp directory. Using node-stream-zip extracting the files from the zip file without unzipping it would look something like this:
const StreamZip = require('node-stream-zip');
const zip = new StreamZip({
file: `/tmp/${myzipfilename}`,
storeEntries: true
});
zip.on('ready', () => {
console.log('All entries read: ' + zip.entriesCount);
});
zip.on('entry', (entry) => {
if ('/' === entry.name[entry.name.length - 1]) {
console.log('[DIR]', entry.name);
return;
}
console.log('[FILE]', entry.name);
zip.stream(entry.name, (err, stream) => {
if (err) {
console.log('Error: ', err.toString());
return;
}
stream.on('error', (err) => {
console.log('[ERROR]', err);
return;
});
stream.pipe(fs.createWriteStream(`/tmp/${entry.name}`));
});
});
Answered By - Rahul Sharma Answer Checked By - Robin (PHPFixing Admin)
Posts
