Download remote files using PHP's ssh2 and ssh2_scp

download_remote_files.php

<?php

// Just for logging
$begin            = microtime(true);
$totalSize        = 0;
$totalQty         = 0;
$totalNotFoundQty = 0;

// Remove script running time limit
set_time_limit(0);

// Change this to your preference, files will be download from here
$remotePath = '/remote/path/to/files/';

// Change this to your preference, files will be downloaded here
$localPath = '/home/username/Downloads/remote-fotos/';

/**
 * list of remote files you want to download
 * there's a lot of ways you can get this, I personally got from database and iterated through it
 * but I won't get this part into details because it's not the objective of this script
 */
$remoteFileNames = array(
    'file-name-1',
    'file-name-2',
    'file-name-3',
);

try {
    // change these to your preference
    $hostname   = 'example_ip';
    $username   = 'username';
    $publicKey  = '/home/username/.ssh/id_rsa.pub';
    $privateKey = '/home/username/.ssh/id_rsa';

    /**
     * connect via ssh
     *
     * There's a known bug with ssh2_connect when your private key use passphrase, in that case, unencrypt your
     * private key and use that new file
     * more details here: http://stackoverflow.com/a/12036066/2312615
     */
    $resourceConn = ssh2_connect($hostname);

    if (!$resourceConn) {
        throw new \Exception('Didn\'t connect');
    }

    // authenticate
    $authenticated = ssh2_auth_pubkey_file($resourceConn, $username, $publicKey, $privateKey);

    if (!$authenticated) {
        throw new \Exception('Didn\'t authenticate');
    }

    // Download one file per iteration
    foreach ($remoteFileNames as $fileName) {

        // creates destiny path if it doesn't exists
        if (!is_dir($localPath)) {
            if (!mkdir($localPath)) {
                throw new \Exception('Could not create destiny folder');
            }
        }

        $remoteFullPath = $remotePath.$fileName;
        $localFullPath  = $localPath.$fileName;

        // Download file from $remoteFullPath to $localFullPath
        $success = ssh2_scp_recv($resourceConn, $remoteFullPath, $localFullPath);

        if (!$success) {
            printf('Couldn\'t download file %s'.PHP_EOL, $fileName);
            $totalNotFoundQty++;

        } elseif (file_exists($localPathFile)) {
            $totalSize += filesize($localPathFile);
            $totalQty ++;
        }

        // Prints a log message every 100 files just to know what's going on
        if ($totalQty % 100 == 0) {
            printf('Downloaded %s files so far'.PHP_EOL, $totalQty);
        }
    }

    // close ssh connection
    if ($resourceConn !== false) {
        unset($resourceConn);
    }

} catch (\Exception $exc) {
    echo "Error: ".$exc->getMessage().PHP_EOL;

    // conexão ssh
    if (isset($resourceConn)) {
        unset($resourceConn);
    }

    exit;
}


$end = microtime(true);

printf("Total files: %d, size: %s MB, not found: %d, script execution time: %ss".PHP_EOL,
    $totalQty,
    number_format($totalSize/1024/1024, 2, ',', '.'),
    $totalNotFoundQty,
    number_format($end - $begin, 2, ',', '.')
);

exit;