AWS Lambda - downloading a file, and using it in the same function - nodejs

Question

I have some certificate files over s3 (public) and I am to download and use these files in my code, If I write an equivalent code in nodejs at my local, it just runs fine, but in AWS lambda it just crashes.

var apn = require('apn');
var https = require('https');
var fs = require('fs');

exports.handler = function(event, context) {
  console.log("Running aws apn push message function");
  console.log("==================================");
  console.log("event", event);

  var certPath = event.certPath;
  var keyPath = event.keyPath;
  var certFileName = event.certFileName;
  var keyFileName = event.keyFileName;
  var passphrase = event.passphrase;
  var apnId = event.apnId;
  var content = event.content;


var certfile = fs.createWriteStream(certFileName);
var certrequest = https.get(certPath, function(certresponse) {
  certresponse.pipe(certfile);
  console.log("downloaded the certificate");

  var keyfile = fs.createWriteStream(keyFileName);
  var keyrequest = https.get(keyPath, function(keyresponse) {
    keyresponse.pipe(keyfile);
    console.log("downloaded the key file");


  var options = { 
                      "cert":certFileName,
                      "key":keyFileName,
                      "passphrase":passphrase,
                      "batchFeedback": true,
                      "interval": 10
                      };

  var apnConnection = new apn.Connection(options);

  var myDevice = new apn.Device(apnId);
  var note = new apn.Notification();
  note.expiry = Math.floor(Date.now() / 1000) + 3600; // Expires 1 hour from now.        
  note.payload = {'COMMAND': content};       
  apnConnection.pushNotification(note, myDevice);
  console.log('message sent to ' + apnId);       

  context.done();

  });
});
}

Error I get is related to accessing files i suppose -

events.js:72 
 throw er; // Unhandled 'error' event 
 ^ 
Error: EACCES, open 'PushChatCert.pem'

So while on AWS Lambda is there some specific concerns when one is downloading a file and using it, related to its path or something, where do the files stay when they get downloaded, in fact I don't even see the log of file getting downloaded.

garnaat · Accepted Answer · 2015-08-12 11:53:12Z

62

The only available local file system you can write to in Lambda is /tmp so make sure the path for the local file you are trying to write to is in the /tmp directory and you should be all set.

edited Aug 12, 2015 at 11:53

answered Aug 11, 2015 at 13:03

garnaat

46k8 gold badges129 silver badges105 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

iddqd · Accepted Answer · 2021-04-07 11:01:21Z

2

Just note as of last year (2020) Lambdas support EFS as a mount as well so you can write to EFS mount point. Excessive for your case..but it might help for someone doing large file processing https://aws.amazon.com/blogs/compute/using-amazon-efs-for-aws-lambda-in-your-serverless-applications/

answered Apr 7, 2021 at 11:01

iddqd

1,3891 gold badge8 silver badges9 bronze badges

Collectives™ on Stack Overflow

AWS Lambda - downloading a file, and using it in the same function - nodejs

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related