How to Fix: Facebook\WebDriver\Exception\UnknownErrorException: unknown error: cannot find Chrome binary – Laravel Dusk

When run the following command in your Laravel Automation Tool Dusk:

php artisan dusk

You get something like the following error:

[[email protected] blog]$ php artisan dusk
PHPUnit 9.3.11 by Sebastian Bergmann and contributors.

E                                                                   1 / 1 (100%)

Time: 00:00.339, Memory: 18.00 MB

There was 1 error:

1) Tests\Browser\ExampleTest::testBasicExample
Facebook\WebDriver\Exception\UnknownErrorException: unknown error: cannot find Chrome binary

/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/php-webdriver/webdriver/lib/Exception/WebDriverException.php:139
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/php-webdriver/webdriver/lib/Remote/HttpCommandExecutor.php:370
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/php-webdriver/webdriver/lib/Remote/RemoteWebDriver.php:136
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/tests/DuskTestCase.php:40
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/laravel/dusk/src/Concerns/ProvidesBrowser.php:200
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/laravel/framework/src/Illuminate/Support/helpers.php:234
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/laravel/dusk/src/Concerns/ProvidesBrowser.php:201
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/laravel/dusk/src/Concerns/ProvidesBrowser.php:95
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/laravel/dusk/src/Concerns/ProvidesBrowser.php:65
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/tests/Browser/ExampleTest.php:21

ERRORS!
Tests: 1, Assertions: 0, Errors: 1.

The error actually appears because you do not have Chrome browser installed on your system. Now, exit from your user shell, and drop back to the root shell. From the root shell, if you are using CentOS 7, you may run the following:

First Download the Latest Chrome RPM:

wget https://dl.google.com/linux/direct/google-chrome-stable_current_x86_64.rpm

Run it with YUM:

yum install ./google-chrome-stable_current_*.rpm

If you are on CentOS 8, you may use dnf installer as following:

dnf localinstall google-chrome-stable_current_x86_64.rpm

Once the installation is done, you may now go back to the user shell and run laravel dusk:

[[email protected] lib64]# su - elastic-keldysh
Last login: Thu Oct  1 15:39:18 IST 2020 on pts/0
[[email protected] ~]$ php artisan dusk
Could not open input file: artisan
[[email protected] ~]$ cd blog
[[email protected] blog]$ php artisan dusk
PHPUnit 9.3.11 by Sebastian Bergmann and contributors.

R                                                                   1 / 1 (100%)

Time: 00:02.367, Memory: 18.00 MB

There was 1 risky test:

1) Tests\Browser\ExampleTest::testBasicExample
This test did not perform any assertions

/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/tests/Browser/ExampleTest.php:16

OK, but incomplete, skipped, or risky tests!
Tests: 1, Assertions: 0, Risky: 1.

It shall work now. Hope this helps.

How to Fix : Failed to connect to localhost port 9515: Connection refused

If you are looking at this post, chances high that, you are trying to run laravel dusk and seeing the following kind of error:

[[email protected] blog]$ php artisan dusk
PHPUnit 9.3.11 by Sebastian Bergmann and contributors.

E                                                                   1 / 1 (100%)

Time: 00:00.331, Memory: 18.00 MB

There was 1 error:

1) Tests\Browser\ExampleTest::testBasicExample
Facebook\WebDriver\Exception\WebDriverCurlException: Curl error thrown for http POST to /session with params: {"capabilities":{"firstMatch":[{"browserName":"chrome","goog:chromeOptions":{"binary":"","args":["--disable-gpu","--headless"]}}]},"desiredCapabilities":{"browserName":"chrome","platform":"ANY","chromeOptions":{"binary":"","args":["--disable-gpu","--headless"]}}}

Failed to connect to localhost port 9515: Connection refused

/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/php-webdriver/webdriver/lib/Remote/HttpCommandExecutor.php:331
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/php-webdriver/webdriver/lib/Remote/RemoteWebDriver.php:136
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/tests/DuskTestCase.php:40
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/laravel/dusk/src/Concerns/ProvidesBrowser.php:200
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/laravel/framework/src/Illuminate/Support/helpers.php:234
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/laravel/dusk/src/Concerns/ProvidesBrowser.php:201
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/laravel/dusk/src/Concerns/ProvidesBrowser.php:95
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/vendor/laravel/dusk/src/Concerns/ProvidesBrowser.php:65
/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/blog/tests/Browser/ExampleTest.php:21

ERRORS!
Tests: 1, Assertions: 0, Errors: 1.

Chorme/Chromium browser runs it’s on 9515 port and laravel dusk tries to connect to it through the Browser binary, but failing to do so. To resolve the case, we first, need to check if chromedriver for linux can run or not.

First, browse your laravel root directory, in my case, it’s the blog directory and then run the chromedriver for linux as following:

cd blog
vendor/laravel/dusk/bin/chromedriver-linux

This should return something like the following if the driver able to load in memory:

[[email protected] blog]$ vendor/laravel/dusk/bin/chromedriver-linux
Starting ChromeDriver 85.0.4183.87 (cd6713ebf92fa1cacc0f1a598df280093af0c5d7-refs/branch-heads/[email protected]{#1689}) on port 9515
Only local connections are allowed.
Please see https://chromedriver.chromium.org/security-considerations for suggestions on keeping ChromeDriver safe.
ChromeDriver was started successfully.

But if it can not be loaded, it will return some kind of error like the following:

[[email protected] blog]$ vendor/laravel/dusk/bin/chromedriver-linux
vendor/laravel/dusk/bin/chromedriver-linux: error while loading shared libraries: libX11-xcb.so.1: cannot open shared object file: No such file or directory

As the error suggests, it is failing to access the library called libX11-xcb. To install it in CentOS, you may run the following from root shell:

[[email protected] lib64]# yum install libX11-xcb*

Once you see the following:

Installed:
  libX11-xcb-1.6.8-3.el8.x86_64

Complete!

You may now, go back to the user shell, and run the chromedriver-linux again:

[[email protected] lib64]# su - elastic-keldysh
Last login: Thu Oct  1 15:28:29 IST 2020 on pts/0
[[email protected] ~]$ cd blog
[[email protected] blog]$ vendor/laravel/dusk/bin/chromedriver-linux
Starting ChromeDriver 85.0.4183.87 (cd6713ebf92fa1cacc0f1a598df280093af0c5d7-refs/branch-heads/[email protected]{#1689}) on port 9515
Only local connections are allowed.
Please see https://chromedriver.chromium.org/security-considerations for suggestions on keeping ChromeDriver safe.
ChromeDriver was started successfully.

Now, you may run the following to start using the laravel dusk:

php artisan dusk

After you are done resolving the 9515 error, you might also have to face another error with Chrome Binary, have a look at the following on how to resolve the error:

How to Install Laravel in Plesk using SSH

In plesk, to install laravel, we need to do two prerequisites first.

  1. Enable SSH for the Plesk User:

2. Add default PHP binary to Plesk Shell to allow using Composer:

Once the above steps are done, now, you may install the laravel installer with the following:

[[email protected] ~]$ composer global require laravel/installer
Changed current directory to /var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/.composer
Using version ^4.0 for laravel/installer
./composer.json has been created
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 12 installs, 0 updates, 0 removals
  - Installing symfony/polyfill-php80 (v1.18.1): Downloading (100%)
  - Installing symfony/process (v5.1.6): Downloading (100%)
  - Installing symfony/polyfill-mbstring (v1.18.1): Downloading (100%)
  - Installing symfony/polyfill-intl-normalizer (v1.18.1): Downloading (100%)
  - Installing symfony/polyfill-intl-grapheme (v1.18.1): Downloading (100%)
  - Installing symfony/polyfill-ctype (v1.18.1): Downloading (100%)
  - Installing symfony/string (v5.1.6): Downloading (100%)
  - Installing psr/container (1.0.0): Downloading (100%)
  - Installing symfony/service-contracts (v2.2.0): Downloading (100%)
  - Installing symfony/polyfill-php73 (v1.18.1): Downloading (100%)
  - Installing symfony/console (v5.1.6): Downloading (100%)
  - Installing laravel/installer (v4.0.5): Downloading (100%)
symfony/service-contracts suggests installing symfony/service-implementation
symfony/console suggests installing symfony/event-dispatcher
symfony/console suggests installing symfony/lock
symfony/console suggests installing psr/log (For using the console logger)
Writing lock file
Generating autoload files
10 packages you are using are looking for funding.
Use the `composer fund` command to find out more!
[[email protected] ~]$

Once this is done, you may try to install laravel using the laravel command:

[[email protected] ~]$ laravel new blog
-bash: laravel: command not found

But, as you can see it is failed. It’s because the laravel binary is installed in the following path:

/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/.composer/vendor/bin

which doesn’t exist in our $PATH variable. Now you may add the above command to your PATH variable using the following tutorial:

I believe, you have already figured it out, it is as simple as the following command:

PATH=$PATH:/var/www/vhosts/elastic-keldysh.139-99-24-82.plesk.page/.composer/vendor/bin

Now, you may run the following to install laravel:

[[email protected] ~]$ laravel new blog

 _                               _
| |                             | |
| |     __ _ _ __ __ ___   _____| |
| |    / _` | '__/ _` \ \ / / _ \ |
| |___| (_| | | | (_| |\ V /  __/ |
|______\__,_|_|  \__,_| \_/ \___|_|

Creating a "laravel/laravel" project at "./blog"
Installing laravel/laravel (v8.0.3)
  - Installing laravel/laravel (v8.0.3): Downloading (100%)

So, yeah, as laravel says, Application ready! Build something amazing.

How to run Composer in Plesk User Shell / Plesk PHP

There are couple of ways you can run composer with Plesk Shell. My favorite one is to add php to your PATH variable, and it will automatically add the composer as well. You may follow through the following to modify your shell path variable to use Plesk PHP:

Once done, now you may run composer command and it shall work:

[[email protected] ~]$ composer -V
Composer version 1.10.5 2020-04-10 11:44:22
[[email protected] ~]$

The other way, is to directly use the composer.phar given from Plesk 9.0 library. This file is available under the following location:

/usr/lib64/plesk-9.0/composer.phar

So, you may run this using the following:

[[email protected] ~]$ /opt/plesk/php/7.4/bin/php /usr/lib64/plesk-9.0/composer.phar -V
Composer version 1.10.13 2020-09-09 11:46:34

This should work too. You may choose any, and it shall work for you. Good luck.

How to Update PATH Variable in Linux

A PATH variable is a system variable that stores the information about the binary files location that you may run for commands. When you log in as an user, or use a custom control panel like Plesk/Cyberpanel/Cpanel, you might want to add some custom paths as a user to take binary commands. One of the example, could be to change the default php path, or a laravel command location from vendor folder. To do this, you need to extend/update the PATH variable for a specific user.

PATH variable extends with the “:”. If you type the following, in your shell, you may see the existing paths in the PATH variable:

[[email protected] ~]$ echo $PATH
/usr/share/Modules/bin:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin

Now, if I want to extend this to take the php binary available in /opt/plesk/php/7.2/bin/php, then we can extend the PATH variable using the following:

PATH=$PATH:/opt/plesk/php/7.2/bin/

Now, if you check, the PATH variable again, you can see it is added:

[[email protected] ~]$ echo $PATH
/usr/share/Modules/bin:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/opt/plesk/php/7.2/bin/
[[email protected] ~]$

We have successfully modified the PATH variable, but only for the existing session. If you want to persist the changes, then, you need to add the command in .bashrc/.profile/.bash_profile file depending on your shell type and OS. You can add to either of the file and test with the following command:

[[email protected] ~]$ echo "PATH=$PATH:/opt/plesk/php/7.2/bin/" >> .profile

Replace .profile with .bashrc or .bash_profile depending on the file that works for you. You may logout and relogin, and then run the echo command again to see if the $PATH is persisting or not.

How to Fix /usr/bin/env: ‘php’: Permission denied in Plesk

If you are seeing an error like the following in your Plesk:

bash-4.4$ laravel
/usr/bin/env: ‘php’: Permission denied

Your binary to php is probably being used through redirection like .bashrc file and an alias is hooked for your php command to work. A better way to do this, is to hook the php binary to your PATH variable. You may do this and fix the error by following this tutorial:

Hope this helps. Thanks.

How to Add PHP in Default Path for Plesk / How to Fix -bash: php: command not found for Plesk User

If you have added SSH access to your plesk user using the following tutorial:

and then, tried to run php command like the following:

[[email protected] ~]$ php -v
-bash: php: command not found

You might have encountered the above error. This is because plesk do not store the php binary in your PATH variable locations. You may check your existing path variables here:

[[email protected] ~]$ echo $PATH
/usr/share/Modules/bin:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin

Plesk stores it’s php binaries for different versions here:

/opt/plesk/php/

So, for example if you are trying to use PHP 7.4 binary, this would be like the following:

[[email protected] php]$ /opt/plesk/php/7.4/bin/php -v
PHP 7.4.10 (cli) (built: Sep  4 2020 03:49:35) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
    with the ionCube PHP Loader + ionCube24 v10.4.2, Copyright (c) 2002-2020, by ionCube Ltd.
    with Zend OPcache v7.4.10, Copyright (c), by Zend Technologies

So, to use only php -v, you need to add this bin path to your path variable. You may do that by running the following command:

PATH=$PATH:/opt/plesk/php/7.4/bin/

Now, you may run the following and it will work:

[[email protected] php]$ php -v
PHP 7.4.10 (cli) (built: Sep  4 2020 03:49:35) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
    with the ionCube PHP Loader + ionCube24 v10.4.2, Copyright (c) 2002-2020, by ionCube Ltd.
    with Zend OPcache v7.4.10, Copyright (c), by Zend Technologies

Now, we need to remember, this will only sustain for the existing session, if we log out and re login, this would be lost. To keep this permanent on each login, we need to put this in the .profile file. You may do this by running the following:

echo "PATH=$PATH:/opt/plesk/php/7.4/bin/" >> .profile

Once done, now you may try to login back again and see php -v is still working:

[[email protected] ~]$ exit
logout
[[email protected] ~]# su - elastic-keldysh
Last login: Thu Oct  1 13:42:13 IST 2020 on pts/0
[[email protected] ~]$ php -v
PHP 7.4.10 (cli) (built: Sep  4 2020 03:49:35) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
    with the ionCube PHP Loader + ionCube24 v10.4.2, Copyright (c) 2002-2020, by ionCube Ltd.
    with Zend OPcache v7.4.10, Copyright (c), by Zend Technologies
[[email protected] ~]$

How to Enable SSH in Plesk User Domain

After you have created the domain from Plesk panel, go to Websites & Domains List, click on your domain to view details of your domain settings.

Now click on FTP access, and from the List click on the main username. In the FTP details for the user page, you will see an option says ‘Access to the server over SSH’ with a drop down that primarily says ‘Forbidden’. You may select the kind of SSH, you would like to give to your user. If you are familiar with the ‘jailshell’ in Cpanel, then it is the option that says ‘/bin/bash (chrooted)’, or you may select /bin/bash to give them normal shell.

Now, you may press ‘Apply’ to set SSH access to the user.

When should you use REST over ORM/DBAL to do Database Operations

Some Background Study

Let’s say, you are architecting a scalable software. Obviously, you would utilize some kind of persistent data storage for your production. If you are developing some kind of transactional software like an ERP/Ecommerce, you are probably more focused into a relational database software like MySQL or MSSQL or PostgreSQL.

Now, one common difficulty for every software architect while working with relational databases, is the ‘Object Relational Impedance Mismatch’ problem. The idea is very straightforward. You design and model your software or programming concept based on Objects, while you store your data in relational tables. Now, how do you map them? As these are different data structures, mapping and utilizing them, is a programming difficulty here.

What is ORM?

In the software world, ORM (Object Relational Mapper) is a form of tool, that exist to resolve the problem. It basically is mapping your relational data into object. That allows you to think your software and data both are stored and operated in Objects. As data is not really stored in an Object, hence, ORM creates an abstraction layer to realize the difference to your software. Using ORM for software design is very useful from architectural point of view, because it takes and returns the same kind of data structure, that you use to design/model your software. It becomes easy to perceive the architecture.

How does DBAL fits here?

As ORM creates an abstraction layer for it’s purpose, it can also be called ‘Database Abstraction Layer’. This is merely conceptual. Now, one purpose of DBAL over ORM, is that DBAL creates the abstraction to keep your software independent from database software alone (Most ORM does the same or helps to achieve the same). So, if you use any of MySQL / MSSQL / Oracle SQL / PostgreSQL or any other SQL based DB engine, it will operate on the same syntax and keep your software compatible out of the box.

So, it’s great, then what’s the problem?

It is obviously conceptually great. But there are cases, when it is better not to use ORM/DBAL. One of the architectural sense of creating abstraction layer in software engineering is that, it creates imperative codes for your mapping. Now, what’s the problem with Imperative codes? If you are unware, Imperative programming refers to the style of programming where we are mainly focused on ‘HOW’ to do something. SQL or relational databases are essentially declarative style of programming, who are focused on ‘WHAT’ to do. For example, when we say ‘select * from users’, it directly gives you the data exists in the users table. We do not care about how does it do it, we only care about the results.

There obviously a catch of declarative code is that, it also creates some kind of abstraction, which uses imperative approach, but it’s underline. For example a Loop in Imperative C is obviously much faster than a loop in Imperative Python (Note: Python can be used in declarative way). But if your software’s imperative code is converting a declarative approach to an imperative piece, then sadly it’s going to be slow, sluggish and less able to scale. ORM or DBAL unfortunately suffers the same. ORM creates an abstraction layer or a slow imperative layer to run declarative SQL. Other cons on using ORM is that, it can duplicate or hobble database structure on your business logic as you are no longer thinking declarative, rather imperative while using ORM.

So where does REST fits in?

To have quicker, simpler and futuristic development, no developer is going to plugin RAW SQL codes in their software. An alternative is to use a declarative REST based api, that uses declarative approach for your database with minimal imperative codes. You can run and consume them as a service with the database software alone. Functional programming is closely related to declarative programming, hence for maximizing performance, you might want to choose a REST api tool that is written in some kind of functional programming language or done in a functional way like with Haskell.

Many database software already started giving HTTP as service protocol with the database software alone, that works in declarative approaches. MySQL comes with a MySQL Router API. PostgreSQL has a solid pREST written in Haskell available in Github. As C# can be written in declarative approach same like Python, there are numerous declarative REST tools written in C# for MSSQL/SQL.

Conclusion

Consuming Declarative API is more like a frontend topic these days since Javascript is taking more functional and declarative futures. React wants you to write codes in declarative approaches, and provides more tools in coming releases with declarative helpers. It is still an odd idea to utilize declarative programming to solve a long existing problem with Object Relational Impedance Mismatch. But then, in the era of millions of users, a declarative database access tool, can cut down a huge amount of cost for infrastructure.

How to Copy a Disk Over SSH?

First, let’s see why do we need to copy a disk over SSH. One is of course for backup. For example if you have a VM on a LVM partition. You want to keep a copy of the block level backups, you prefer to create a snapshot of the lvm partition and then copy the disk as an image to your backup server. The other being quite the same, but for different purpose. What if you want to migrate a VM that you have created on an LVM partition, and then you want to migrate it as a raw file to another server? Or a LVM partition to another server? For those cases, the technique is pretty awesome.

Copy The Disk to a RAW Image

First, let’s learn how can copy a disk as raw image.

For example, you are sitting in your backup server. And you want to copy a disk or lvm partition or a partition of a disk, from a remote server to your backup server. And you want to keep the copy of the image, then you may run dd command as following from your backup server:

ssh [email protected] "dd if=/dev/vg0/v1092-kdkdksjuekksq" | dd of=/backup/v1092.raw

In our case, 10.10.10.10 is the IP of the server, that partition/disk currently reside. We are trying to copy a LVM partition namely: /dev/vg0/v1092-kdkdksjuekksq, just replace this one with the one your desired lvm partition. You may also do this for a disk like /dev/sda, the command would be like the following then:

ssh [email protected] "dd if=/dev/sda" | dd of=/backup/v1092.raw

Now as you have copied the disk/partition, you may look at what the partition holds by checking the data inside it. To know, how to mount a raw disk image, you may check the following:

How-to-Mount-raw-VM-disk-images-KVMorXenorVMW

Copy The Disk To Another Remote Disk over SSH

You may either copy the disk directly to a secondary disk you have on the backup/migrated server or dump the image that you copied to another disk/partition of same size or bigger. To copy directly a partition /dev/sda from another server, to a backup server with the secondary disk /dev/sdb, you may do the following:

ssh [email protected] "dd if=/dev/sda" | dd of=/dev/sdb

This would backup /dev/sda from 10.10.10.10 and restore to /dev/sdb drive you have on the server that ran the command.

To just dump the image file, that copied earlier on the other example to /dev/sdb, you may do the following:

dd if=/backup/v1092.raw of=/dev/sdb

Hope this helps.