AWS Node Lambda to send back binary image in response - node.js

Question

I am using an AWS Node Lambda to resize an image and send that image back in binary format, and I am not sure if I am handling this right or not. Basically, I want to send the binary data back in my response in a way that it can just be loaded without any front end changes. I have a perfectly good version working that returns base64 data, but how would I modify this to return binary instead?
Here is my resizing function:
function imageSizer(url, args) {
return new Promise((resolve, reject) => {
bufferRequest.get(url, args, function (err, res, body) {
if (err) {
console.log(err);
reject(err);
}
const originalFormat = url.includes('png') ? 'png' : 'jpeg';
let newSize = (args.exact === true)
? sharp(body).resize(args.width, args.height)
: sharp(body).resize(args.width, args.height).max();
newSize.toFormat(originalFormat)
.toBuffer()
.then((outputBuffer) => {
const newImage = "data:" + res.headers["content-type"] + ";base64," + new Buffer(outputBuffer).toString('base64');
resolve(newImage);
})
.catch((error) => {
console.log(error);
reject(error);
})
});
})
}
Here is my handler:
function handler(event, context) {
imageSizer(event.url, event.queryStringParameters);
.then((result) => {
context.succeed({
statusCode: 200,
headers: { 'Content-Type': 'image/jpeg'},
body: result
});
})
.catch((error) => {
context.succeed({
statusCode: 502,
headers: { 'Content-Type': 'application/json' },
body: `Error sizing image ${error}`
});
})
}
As mentioned, this works fine for base64 but I am unsure what changes to make to const newImage = to send back binary data the browser can use to load the image.

Answer 1

I went with this solution:
Change:
.then((outputBuffer) => {
const newImage = "data:" + res.headers["content-type"] + ";base64," + new Buffer(outputBuffer).toString('base64');
resolve(newImage);
})
To:
.then((outputBuffer) => {
resolve(outputBuffer);
})
This returns the buffer in binary format, without having to do anything ourselves.