Can AWS Lambda reach/interact with S/FTP? - node.js

Question

I wrote some basic js to just list the files of a FTP but I get:
"Process exited before completing request"
Is that because Lambda can't interact with FTP?
I'm using jsftp btw.
Here's my setup:
I use Serverless to create the project
For my lambda, I used nodejs and I'm using JSFTP to deal with the ftp stuff.
My code:
// Require Serverless ENV vars
var ServerlessHelpers = require('serverless-helpers-js').loadEnv();
// Require Logic
var lib = require('../lib');
// Lambda Handler
module.exports.handler = function (event, context) {
lib.respond(event, function (error, response) {
return context.done(error, response);
});
};
My ftp lambda code:
var JSFtp = require("jsftp");
module.exports.respond = function (event, cb) {
var ftp = new JSFtp({
host: "host",
user: "user",
password: "password"
});
ftp.auth(ftp.user, ftp.password, function(err, res) {
if (err) console.log(err);
else console.log(res);
ftp.ls(".", function (err, res) {
var results = [];
res.forEach(function (file) {
results.push(file.name);
});
ftp.raw.quit();
return cb(null, results.length);
})
});
};
I added some console.log() all over the place and it seems like it choked once it tried to ftp.auth.
The output I see in cloud watch:
START RequestId: __ID__ Version: $LATEST
END RequestId: __ID__
REPORT RequestId: __ID__ Duration: 526.46 ms Billed Duration: 600 ms Memory Size: 1024 MB Max Memory Used: 33 MB
Process exited before completing request
So it looks like it just choked somewhere...

Answer 1

in short, ftp will not work with lambda since they use ephemeral ports.
sftp will work nicely with lambda. i tested using java code via jsch with no issues; tho i cant see how it wouldnt work with any js sftp lib.

Answer 2

It is possible tested just now.
Make sure ur timeout is set to be long enough and you are calling context.succeed() on process termination
function __main__(event, context) {
var JSFtp = require("jsftp");
var ftp = new JSFtp({
host: "speedtest.tele2.net",
port: 21, // defaults to 21
});
ftp.ls(".", function(err, res) {
var results = []; res.forEach(function(file) {
results.push(file.name);
});
context.succeed(results);
});
};

Answer 3

By default, Lambda functions only have 3 seconds to complete. If it takes longer than that, you'll get the error you are seeing.
You can adjust the timeout to anything up to 5 minutes. To change it using the aws CLI, run:
aws lambda update-function-configuration --function-name my-lambda-function --timeout 300