Zero Downtime deploy project to server (production)

Envoy.blade.php

@servers(['production' => '[email protected]'])

@setup
    $repo = '[email protected]:<username>/<project-name>.git';
    date_default_timezone_set('Asia/Kathmandu');
    $release = date('YmdHis');

    $releases_dir = '/var/www/html/final/releases';
    $app_dir = '/var/www/html/final';
    $new_release_dir = $releases_dir .'/'. $release;

    $env = $app_dir . '/.env';
    $storage = $app_dir . '/storage';
@endsetup

@story('deploy')
    clone_repository
    run_composer
    update_symlinks
    migrate
    live
    permissions
    clean_old_releases
@endstory

@task('clone_repository')
    echo 'Cloning Repository'
    git clone --depth 1 -b {{ $branch }} {{ $repo }} {{ $new_release_dir }}
@endtask

@task('run_composer')
    echo 'Installing composer dependencies';
    cd {{ $new_release_dir }}
    composer install --optimize-autoloader --no-dev
@endtask

@task('update_symlinks')
    echo "Linking storage directory"
    rm -rf {{ $new_release_dir }}/storage
    ln -nfs {{ $storage }} {{ $new_release_dir }}/storage

    echo 'Linking .env file'
    ln -nfs {{ $env }} {{ $new_release_dir }}/.env
@endtask

@task('migrate')
    echo 'Running migrations';
    cd {{ $new_release_dir }};
    php artisan migrate --force;
@endtask


@task('live')
    echo 'Linking current release'
    ln -nfs {{ $new_release_dir }} {{ $app_dir }}/current
@endtask

@task('permissions')
    echo "Changing Permission ({{ $release }})"
    sudo chown $USER:www-data -R bootstrap/cache storage public
    sudo chmod 775 -R bootstrap/cache storage public
    
    # sudo (chown | chmod) will only work if you enable NOPASSWD in /etc/sudoers for particular $USER. 
@endtask


@task('clean_old_releases')
    # This will list our releases by modification time and delete all but the 3 most recent.
    # This will leave the two releases and delete old releases.

    purging=$(ls -dt {{ $releases_dir }}/* | tail -n +3);

    if [ "$purging" != "" ]; then
    echo Purging old releases: $purging;
    rm -rf $purging;
    else
    echo "No releases found for purging at this time";
    fi
@endtask