Direct Image to S3 download function - access to data.key - node.js

Question

I've been trying to figure this out for two days now.
I have the below function working, it basically takes URL and upload the file to S3. However the problem is I'm trying to return the file location on S3 (data.key) out of the main function but I'm either getting undefined or promise(pending).
var express = require("express"),
axios = require('axios').default,
stream = require("stream"),
aws = require('aws-sdk')
async function downloadImage(url) {
let contentType = 'application/octet-stream'
const s3 = new aws.S3();
// This returns undefined
var imageUrl
// This returns Promise { <pending>}
// var imageUrl = await uploadS3()
var imageRequest = axios({
method: 'get',
url: url,
responseType: 'stream'
}).then(function (response) {
if (response.status === 200) {
contentType = response.headers['content-type'];
response.data.pipe(uploadS3());
}
}).catch(function (error) {
console.log(error.message);
})
// This is where I can't get return
return imageUrl
function uploadS3() {
var pass = new stream.PassThrough();
var params = {
Bucket: "test_bucket",
Key: "test/" + Date.now().toString(),
Body: pass,
ContentType: contentType,
}
s3.upload(params, function (err, data) {
if (err) {
console.log(err)
} else {
// I have access to data.key only here
imageUrl = data.key
console.log(imageUrl)
}
})
return pass
}
}
I was trying something like this. This gets the value up to the Then of the first function, but still no luck getting it out of the main funciton
async function uploadImage(url) {
let contentType = 'application/octet-stream'
const s3 = new aws.S3();
// var imageUrl = await uploadStream()
// var imageUrl = await Promise.all
var imageUrl
var imageRequest = axios({
method: 'get',
url: url,
responseType: 'stream'
}).then(function (response) {
if (response.status === 200) {
const { writeStream, promise } = uploadStream();
contentType = response.headers['content-type'];
upload = response.data.pipe(writeStream);
promise.then((data) => {
// I have access to it here, but not
console.log(data.key)
imageUrl = data.key
}).catch((err) => {
console.log('upload failed.', err.message);
});
}
}).catch(function (error) {
console.log(error.message);
})
return imageUrl
function uploadStream() {
var pass = new stream.PassThrough();
var params = {
Bucket: "test_bucket",
Key: "test/" + Date.now().toString(),
Body: pass,
ContentType: contentType,
}
return {
writeStream: pass,
promise: s3.upload(params).promise(),
};
}
}

Answer 1

I was able to get it to work the following way if anybody is interested. I have a Promise created which returns a result (which is file location on S3) once upload is completed.
I then use this inside of my main functions to basically do download and then return the location.
var express = require("express"),
axios = require('axios').default,
stream = require("stream"),
aws = require('aws-sdk')
// This is now can be run from any other function while getting access to file location (result)
uploadImageAsync("imageURLGoesHere").then(function (result) {
// result contains the location on S3 data.key (this can be changed in the code to return anything else from data)
console.log(result)
}, function (err) {
console.log(err);
})
async function uploadImageAsync(url) {
let contentType = 'application/octet-stream'
const s3 = new aws.S3();
return new Promise(function (resolve, reject) {
var imageRequest = axios({
method: 'get',
url: url,
responseType: 'stream'
}).then(function (response) {
if (response.status === 200) {
const { writeStream, promise } = uploadStream();
contentType = response.headers['content-type'];
response.data.pipe(writeStream);
return new Promise(function (resolve, reject) {
promise.then((data) => {
resolve(data.key);
}).catch((err) => {
console.log('upload failed.', err.message);
});
});
}
}).catch(function (error) {
console.log(error.message);
})
imageRequest.then(function (result) {
resolve(result);
})
function uploadStream() {
var pass = new stream.PassThrough();
var params = {
Bucket: "test_bucket",
Key: "test/" + Date.now().toString(),
Body: pass,
ContentType: contentType,
}
return {
writeStream: pass,
promise: s3.upload(params).promise(),
};
}
})
}