upload dynamically generated pdf from aws-lambda into aws-s3 - angularjs

Question

In my serverless app, I want to create pdf which is generated dynamically and then upload that created pdf into aws s3. My problem is, when a url is returned to client-side code from server, uploaded url doesn't working. My code is given below:
Client-side javascript code (angular.js)
$scope.downloadAsPDF = function() {
// first I have to sent all html data into server
var html = angular.element('html').html(); // get all page data
var service = API.getService();
service.downloadPdf({}, { html : html }, // api call with html data
function(res) {
console.log("res : ", res);
window.open(res.url); // open uploaded pdf file
// err: The server replies that you don't have permissions to download this file
// HTTP/1.1 403 Forbidden
}, function(err) {
console.log("err : ", err);
});
};
Serverless Code
var fs = require('fs');
var pdf = require('html-pdf');
var AWS = require("aws-sdk");
var s3 = new AWS.S3();
module.exports.handler = function(event, context) {
if (event.html) { // client html data
AWS.config.update({
accessKeyId: 'xxxxxxxxxxxxxxxxx',
secretAccessKey: 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
region: 'xxxxxxxxxxxxxxxxxxxx'
});
var awsInfo = {
bucket: 'xxxxx-xxxxxx'
};
var baseUrl = 'https://s3-my-region.amazonaws.com/s3-upload-directory';
var folderRoot = 'development/pdf';
// unique file name
var output_filename = Math.random().toString(36).slice(2) + '.pdf';
// file created directory
var output = '/tmp/' + output_filename;
pdf.create(event.html, options).toStream(function(err, stream) {
if( err ) {
console.log('pdf err : ', err);
} else {
writeStream =fs.createWriteStream(output);
s3.putObject({
Bucket : awsInfo.bucket,
Key : folderRoot + '/' + output_filename,
Body : fs.createReadStream(output),
ContentType : "application/pdf"
},
function(error, data) {
if (error != null) {
console.log("error: " + error);
} else {
// upload data: { ETag: '"d41d8cd98f00b204e9800998ecf8427e"' }
console.log('upload data : ', data);
return cb(null, {
// return actual aws link, but no file
// ex: 'https://s3-my-region.amazonaws.com/s3-upload-directory/output_filename.pdf
url: baseUrl + '/' + output_filename
});
}
});
}
}
};

Answer 1

I've solve my problem. I was trying to upload pdf before I generate pdf. I have solve this problem using the following code:
pdf.create(event.html, options).toStream(function(err, stream) {
if (err) {
console.log('pdf err : ', err);
} else {
var stream = stream.pipe(fs.createWriteStream(output));
stream.on('finish', function () {
s3.putObject({
Bucket : awsInfo.bucket,
Key : folderRoot + '/' + output_filename,
Body : fs.createReadStream(output),
ContentType : "application/pdf"
},
function(error, data) {
if (error != null) {
console.log("error: " + error);
return cb(null, {
err: error
});
} else {
var url = baseUrl + '/' + output_filename
return cb(null, {
url: url
});
}
});
});
}
});

Answer 2

I have done similar kind of thing before. I want a few clarifications from you and then I will be able to help you better.
1) In your code (server side), you have mentioned in the callback function that actual aws link is getting returned.
Are you sure that your file is getting uploaded to Amazon s3. I mean did you check your bucket for the file or not?
2) Have you set any custom bucket policy on Amazon s3. Bucket policy play an important role in what can be downloaded from S3.
3) Did you check the logs to see exactly which part of code is causing the error?
Please provide me this information and I think the I should be able to help you.

Answer 3

if we don't want to upload at s3 just return generated file from aws-lambda.