I'm trying to connect to a SFTP-Server and list the documents in the /ARCHIVE Folder. Credentials are stored in a .env file. When I run this on my local machine it works and lists the documents.

async function main (event){

    let Client = require('ssh2-sftp-client');

    let sftp = new Client();

    const dotenv = require('dotenv');

    dotenv.config();



    const ftpOptions = {

        host: process.env.FTP_HOST,

        port: process.env.FTP_PORT,

        username: process.env.FTP_USER,

        password: process.env.FTP_PASSWORD,

        debug: console.log

    }



    await sftp.connect(ftpOptions);

    let documentList = await sftp.list('/ARCHIVE');

    console.log(documentList);

    sftp.end();

}

But if I try it in my AWS lambda function, it tries to connect and times out. The env variables are loaded and avaiable before the sftp.connect(ftpOptions) is executed. The logs show that the function is trying to connect to the server, but can't even login with the credentials.

Function Logs:

START RequestId: 20d3c3b7-19d8-49cf-8997-1f2331eb0b6e Version: $LATEST

2020-06-04T08:27:12.837Z    20d3c3b7-19d8-49cf-8997-1f2331eb0b6e    INFO    Debugging turned on

2020-06-04T08:27:12.860Z    20d3c3b7-19d8-49cf-8997-1f2331eb0b6e    INFO    DEBUG: Local ident: 'SSH-2.0-ssh2js0.4.10'

2020-06-04T08:27:12.898Z    20d3c3b7-19d8-49cf-8997-1f2331eb0b6e    INFO    DEBUG: Client: Trying ftp_foo.com on port 22 ...

2020-06-04T08:27:32.929Z    20d3c3b7-19d8-49cf-8997-1f2331eb0b6e    INFO    CLIENT[sftp]: Connection attempt 1 failed. Trying again.

2020-06-04T08:27:33.931Z    20d3c3b7-19d8-49cf-8997-1f2331eb0b6e    INFO    DEBUG: Local ident: 'SSH-2.0-ssh2js0.4.10'

2020-06-04T08:27:33.931Z    20d3c3b7-19d8-49cf-8997-1f2331eb0b6e    INFO    DEBUG: Client: Trying ftp_foo.com on port 22 ...

2020-06-04T08:27:53.951Z    20d3c3b7-19d8-49cf-8997-1f2331eb0b6e    INFO    CLIENT[sftp]: Exhausted all connection attempts. Giving up

2020-06-04T08:27:53.957Z    20d3c3b7-19d8-49cf-8997-1f2331eb0b6e    ERROR   Invoke Error    {errorType:Error,errorMessage:connect: Timed out while waiting for handshake after 2 attempts,code:ERR_GENERIC_CLIENT,custom:true,stack:[Error: connect: Timed out while waiting for handshake after 2 attempts,    at Object.formatError (/var/task/node_modules/ssh2-sftp-client/src/utils.js:62:18),    at Client.connectErrorListener (/var/task/node_modules/ssh2-sftp-client/src/index.js:98:21),    at Object.onceWrapper (events.js:417:26),    at Client.emit (events.js:310:20),    at Timeout._onTimeout (/var/task/node_modules/ssh2/lib/client.js:697:14),    at listOnTimeout (internal/timers.js:549:17),    at processTimers (internal/timers.js:492:7)]}

2020-06-04T08:27:53.959Z    20d3c3b7-19d8-49cf-8997-1f2331eb0b6e    ERROR   Unhandled Promise Rejection     {errorType:Runtime.UnhandledPromiseRejection,errorMessage:Error: end: No SFTP connection available,reason:{errorType:Error,errorMessage:end: No SFTP connection available,code:ERR_NOT_CONNECTED,custom:true,stack:[Error: end: No SFTP connection available,    at formatError (/var/task/node_modules/ssh2-sftp-client/src/utils.js:62:18),    at Object.haveConnection (/var/task/node_modules/ssh2-sftp-client/src/utils.js:612:20),    at /var/task/node_modules/ssh2-sftp-client/src/index.js:1248:19,    at new Promise (<anonymous>),    at SftpClient.end (/var/task/node_modules/ssh2-sftp-client/src/index.js:1236:12),    at downloadPDFs (/var/task/index.js:40:14),    at processTicksAndRejections (internal/process/task_queues.js:97:5)]},promise:{},stack:[Runtime.UnhandledPromiseRejection: Error: end: No SFTP connection available,    at process.<anonymous> (/var/runtime/index.js:35:15),    at process.emit (events.js:310:20),    at processPromiseRejections (internal/process/promises.js:209:33),    at processTicksAndRejections (internal/process/task_queues.js:98:32)]}

[ERROR] [1591259273978] LAMBDA_RUNTIME Failed to post handler success response. Http response code: 403.

Is there maybe something, that happens on my local machine to provide the connection which I didn't implemented in the lambda function?