How to save a file on S3 from a lambda function
Posted on October 16, 2022
Here the code I use when I need to save on Amazon AWS S3 service from within a lambda function. I generally use Netlify but it should be the same in other platforms as well.
// save.js
const aws = require('aws-sdk')
aws.config.region = 'eu-west-3' // specify your region
module.exports = (buffer, file) => {
return new Promise((resolve, reject) => {
const s3 = new aws.S3({
accessKeyId: process.env.FUNC_AWS_ACCESS_KEY_ID,
secretAccessKey: process.env.FUNC_AWS_SECRET_ACCESS_KEY
})
// you can change the following setting based on your AWS settings
const s3Params = {
Bucket: process.env.S3_BUCKET_NAME,
Key: file.url,
Body: buffer,
Expires: 60 * 2,
ContentType: file.ct,
ACL: 'public-read'
}
s3.putObject(s3Params, function (err, data) {
if (err) reject(err)
resolve(data)
})
})
}
Here how to use the above component:
// index.js
const save = require('./save.js')
exports.handler = async (event, context) => {
await save(JSON.stringify({hello:true}), { url: 'filename.json', ct: 'application/json' })
return {
statusCode: 200,
body: 'OK'
}
}
A note on the environment variable names:
The AWS environment variable need a different name because the AWS default one are reserved in Netlify functions, so instead of AWS_ACCESS_KEY_ID you can use FUNC_AWS_ACCESS_KEY_ID and so on.