How to Fix – Rongta 80mm Thermal Printer – Firefox – ‘an unknown error occurred while printing’

Rongta 80mm Thermal printer is the most popular POS receipt printer in the world. It can run on a regular 80mm printer driver for windows. It is possible to print receipts from a web browser like firefox or chrome to Rongta printers. Although there are times, it might become hectic with different printing issues to send the printing data to the printer from the browser.

If you are trying to print your POS receipt from Firefox for a Rongta printer, a common problem, that appears time to time, is the following:

An unknown error occurred while printing

You probably failed to resolve the issue, even after uninstalling the Firefox or by Refreshing Firefox settings, or by clearing the printer saved settings on your browser. The issue is very weird. For some reason, Javascript’s window print fails to send the data to Printer through firefox, even though it thinks it did. I tried digging several things, but nothing worked until I found a way to actually make firefox think, it’s a new printer. Here are the steps you may following.

  1. Close the firefox, and make your Rongta 80mm printer the default printer of your system.
  2. Now open firefox, and type ‘about:support’ & enter.
  3. It will open a page. Scroll down to the printing section where it says Troubleshooting with ‘Clear saved print settings’. Click on the button to clear the settings.
  4. From the top press ‘Refresh Firefox’ button.
  5. Now restart your firefox, and type ‘about:config’. These is the firefox configurable environmental variables, that we wish to change some.
  6. Before we do, we first need to make firefox save, Rongta settings. One quick way of doing this is to open a new tab, browse google.com, now go to Print from the File tab, it will show you ‘Advanced Preference’, now from the Print button at the top, make sure Rongta 80mm printer is selected and press Print. It will probably not print anything, but what it will help to do, is creating our printer settings in firefox.
  7. Now go back to the tab with ‘about:config’, at the top, type ‘print’ without quotes in the box that says ‘Search for preference’
  8. A lot of settings should appear, a couple of things you need to change.
  9. Delete print_printer or print.print_printer row.
  10. Set print.print_via_parent boolean value to ‘true’.
  11. Set print.tab_modal.enabled to ‘false’
  12. Make sure dom.enable_window_print this is set to ‘true’
  13. Make sure print.show_print_progress is set to ‘true’
  14. Now, close the window, and restart your firefox again.

You should now be able to print your POS receipt using Rongta 80mm printer using Firefox.

How to Setup Odoo 14 in CentOS 7

Odoo is currently one of the most popular tool for business purposes. It has a community edition, that allows managing ERP at very low cost. Odoo was previously known as OpenERP. Odoo requires to be installed on a dedicated server or VPS. Odoo 14 had come out already. I will have a straight forward how to on installing the latest Odoo 14 in CentOS 7.

Log in to your system and update

First step would be to login to your system and then update the system using yum.

ssh [email protected]_ip

You may check the CentOS version from the redhat release file using the following:

cat /etc/redhat-release

It should show you something like the following if you

CentOS Linux release 7.8.2003 (Core)

Now, you may try updating the system with yum

yum update -y

Once done, now install the EPEL repository as we need it to satisfy a couple of dependecies:

yum install epel-release

Install Python 3.6 packages and Odoo dependencies

We need Python 3.6 at least to run Odoo 14. Odoo 13 also ran on Python 3.6. We will use ‘Software Collection (scl)’ repository to install and use Python 3.6. To find the available Python versions in SCL, you may check the following:

SCL Repository for Python

Now, to install Python 3.6 using SCL, we first need to install the SCL repository for Centos:

yum install centos-release-scl

Once the SCL is loaded, now, you may install the python 3.6 using the following command:

yum install rh-python36

Once the Python is installed, now we will install several tools and packages for Odoo dependencies with the following command:

yum install git gcc nano wget nodejs-less libxslt-devel bzip2-devel openldap-devel libjpeg-devel freetype-devel

Create Odoo User

We now need to create a system user and group for Odoo and define a home directory to /opt/odoo

useradd -m -U -r -d  /opt/odoo -s /bin/bash odoo

You may use any username here, but remember to create the same username for the PostgreSQL as well.

Install PostgreSQL

CentOS base repository unfortunately, comes with Postgresql 9.2. But we want to use PostgreSQL 10 for our Odoo installation. You may check the available PostgreSQL for CentOS 7 using the following command:

yum list postgresql*

As by default CentOS 7 does not provide the PostgreSQL 10, we would use PostgreSQL official repository to download and install the 10 version.

First, we install the Postgres Yum Repository using the following command:

yum install https://download.postgresql.org/pub/repos/yum/10/redhat/rhel-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm

Now, you may install PostgreSQL 10 and related required packages using the following command:

yum install postgresql10 postgresql10-server postgresql10-contrib postgresql10-libs -y

Now, we need to initialize the postgres database and start it. You may do that using the following:

# Initialize the DB
/usr/pgsql-10/bin/postgresql-10-setup initdb

# Start the database
systemctl start postgresql-10.service

If everything goes alright, now you may check the postgresql 10 status:

[[email protected] bin]# systemctl status postgresql-10.service
● postgresql-10.service - PostgreSQL 10 database server
   Loaded: loaded (/usr/lib/systemd/system/postgresql-10.service; disabled; vendor preset: disabled)
   Active: active (running) since Mon 2021-04-05 16:42:15 EDT; 5s ago
     Docs: https://www.postgresql.org/docs/10/static/
  Process: 6380 ExecStartPre=/usr/pgsql-10/bin/postgresql-10-check-db-dir ${PGDATA} (code=exited, status=0/SUCCESS)
 Main PID: 6386 (postmaster)
    Tasks: 8
   Memory: 13.5M
   CGroup: /system.slice/postgresql-10.service
           ├─6386 /usr/pgsql-10/bin/postmaster -D /var/lib/pgsql/10/data/
           ├─6388 postgres: logger process
           ├─6390 postgres: checkpointer process
           ├─6391 postgres: writer process
           ├─6392 postgres: wal writer process
           ├─6393 postgres: autovacuum launcher process
           ├─6394 postgres: stats collector process
           └─6395 postgres: bgworker: logical replication launcher

Now you may enable Postgres to start when booting up using the systemctl enable command:

systemctl enable postgresql-10.service

Now, we need to create a database user for our Odoo installation. You may do that using the following:

su - postgres -c "createuser -s odoo"

Note: If you have created a different user for Odoo installation other than ‘odoo’ than you should change the username here as well.

Install Wkhtmltopdf

Wkhtmltopdf is a open source tool to make html in pdf format so that you may print pdf reports. This tool is used by Odoo and requires to be installed as dependency. CentOS 7 repository does not provide the latest version of this tool, and Odoo requires you to use the latest version. Hence, we require to download the latest version from the Wkhtmltopdf website and install it. To do that, you may first visit the page:

https://wkhtmltopdf.org/downloads.html

The page gives you the direct rpm download link for each version of CentOS/Ubuntu/Mac etc. Download the stable version for CentOS 7. At the time of writing, the URL for CentOS 7 x86_64 bit is the following:

https://github.com/wkhtmltopdf/packaging/releases/download/0.12.6-1/wkhtmltox-0.12.6-1.centos7.x86_64.rpm

You may install this using the following:

cd /opt/
wget https://github.com/wkhtmltopdf/packaging/releases/download/0.12.6-1/wkhtmltox-0.12.6-1.centos7.x86_64.rpm
yum localinstall wkhtmltox-0.12.6-1.centos7.x86_64.rpm

Install and Configure Odoo 14

If you have come all through here, that means you are done with the all dependency installations before starting to download Odoo 14 source code. We will download Odoo 14 from it’s Github repo and use virtualenv to create an isolated python environment to install this python software.

First, login as odoo from root:

su - odoo

Clone the Odoo source code from Github repository:

git clone https://www.github.com/odoo/odoo --depth 1 --branch 14.0 /opt/odoo/odoo14

This will bring the Odoo 14 branch from the Odoo repository and put it inside the folder /opt/odoo/odoo14

Now, we need to enable software collections in order to access python binaries:

scl enable rh-python36 bash

Then we need to create a virtual environment to complete the installation:

cd /opt/odoo
python3 -m venv odoo14-venv

Now, you may activate the virtual environment you have just created:

source odoo14-venv/bin/activate

Now, we upgrade the pip and install the wheel library:

pip install --upgrade pip
pip3 install wheel

Once done, now we can using pip3 to install all the required Python modules from the requirements.txt file:

pip3 install -r odoo14/requirements.txt

Once the installation is complete, now we can deactivate the virtual environment and get back to the root user

deactivate && exit ; exit

If you think, you will create custom modules, you may now create it and give odoo the permission accordingly:

mkdir /opt/odoo/odoo14-custom-addons
chown odoo: /opt/odoo/odoo14-custom-addons

Now, we can fill up the odoo configuration file. First open the odoo.conf file:

nano /etc/odoo.conf

You may paste the following inside:

[options]
; This is the password that allows database operations:
admin_passwd = set_the_password_to_create_odoo_database
db_host = False
db_port = False
db_user = odoo
db_password = False
addons_path = /opt/odoo/odoo14/addons,/opt/odoo/odoo14-custom-addons
; You can enable log file with uncommenting the next line
; logfile = /var/log/odoo14/odoo.log

Please do not forget to change the password ‘set_the_password_to_create_odoo_database’ with a new strong password. This would be used to create Odoo databases from the login screen.

Create the systemd service file and start Odoo 14

Now, we will create a service file, to be able to start, stop and restart Odoo daemon. To do that, first create a service file using the following:

nano /etc/systemd/system/odoo14.service
[Unit]
Description=Odoo14
Requires=postgresql-10.service
After=network.target postgresql-10.service
[Service]
Type=simple
SyslogIdentifier=odoo14
PermissionsStartOnly=true
User=odoo
Group=odoo
ExecStart=/usr/bin/scl enable rh-python36 -- /opt/odoo/odoo14-venv/bin/python3 /opt/odoo/odoo14/odoo-bin -c /etc/odoo.conf
StandardOutput=journal+console
[Install]
WantedBy=multi-user.target

Now, save the file and exit.

Now, you need to reload the systemd daemon to be able to read the latest changes you have made to services. To do that, run:

systemctl daemon-reload

Finally, now we can start Odoo 14 instance using the following command:

systemctl start odoo14

If you are interested to check the status of the instance, you may do this:

systemctl status odoo14

It show green active running, if everything worked out. If you see no error, you may now enable Odoo to start during the boot:

systemctl enable odoo14

If you would like to see the logs, you may either use the journal tools like the following:

journalctl -u odoo14

or uncomment the following line to log the debugs in /etc/odoo.conf

logfile = /var/log/odoo14/odoo.log

After making any change to /etc/odoo.conf, do not forget the restart the Odoo14 instance using systemctl.

Test the Installation


Odoo is currently one of the most popular tool for business purposes. It has a community edition, that allows managing ERP at very low cost. Odoo was previously known as OpenERP. Odoo requires to be installed on a dedicated server or VPS. Odoo 13 had come out on October, 2019. Odoo 14 hasn’t been released yet for production. I will have a straight forward how to on installing the latest Odoo 13 in CentOS 7.

Log in to your system and update

First step would be to login to your system and then update the system using yum.ssh [email protected]_ip

You may check the CentOS version from the redhat release file using the following:cat /etc/redhat-release

It should show you something like the following if youCentOS Linux release 7.8.2003 (Core)

Now, you may try updating the system with yumyum update -y

Once done, now install the EPEL repository as we need it to satisfy a couple of dependecies:yum install epel-release

Install Python 3.6 packages and Odoo dependencies

We need Python 3.6 at least to run Odoo 13. Odoo 12 had support for Python 3.5, unfortunately, Odoo 13 doesn’t. We will use ‘Software Collection (scl)’ repository to install and use Python 3.6. To find the available Python versions in SCL, you may check the following:

SCL Repository for Python

Now, to install Python 3.6 using SCL, we first need to install the SCL repository for Centos:yum install centos-release-scl

Once the SCL is loaded, now, you may install the python 3.6 using the following command:yum install rh-python36

Once the Python is installed, now we will install several tools and packages for Odoo dependencies with the following command:yum install git gcc nano wget nodejs-less libxslt-devel bzip2-devel openldap-devel libjpeg-devel freetype-devel

Create Odoo User

We now need to create a system user and group for Odoo and define a home directory to /opt/odoouseradd -m -U -r -d /opt/odoo -s /bin/bash odoo

You may use any username here, but remember to create the same username for the PostgreSQL as well.

Install PostgreSQL

CentOS base repository unfortunately, comes with Postgresql 9.2. But we want to use PostgreSQL 9.6 for our Odoo installation. You may check the available PostgreSQL for CentOS 7 using the following command:yum list postgresql*

As by default CentOS 7 does not provide the PostgreSQL 9.6, we would use PostgreSQL official repository to download and install the 9.6 version.

First, we install the Postgres Yum Repository using the following command:yum install https://download.postgresql.org/pub/repos/yum/9.6/redhat/rhel-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm

Now, you may install PostgreSQL 9.6 and related required packages using the following command:yum install postgresql96 postgresql96-server postgresql96-contrib postgresql96-libs

Now, we need to initialize the postgres database and start it. You may do that using the following:# Initialize the DB/usr/pgsql-9.6/bin/postgresql96-setup initdb# Start the databasesystemctl start postgresql-9.6.service

Now you may enable Postgres to start when booting up using the systemctl enable command:systemctl enable postgresql-9.6.service

Now, we need to create a database user for our Odoo installation. You may do that using the following:su – postgres -c “createuser -s odoo”

Note: If you have created a different user for Odoo installation other than ‘odoo’ than you should change the username here as well.

Install Wkhtmltopdf

Wkhtmltopdf is a open source tool to make html in pdf format so that you may print pdf reports. This tool is used by Odoo and requires to be installed as dependency. CentOS 7 repository does not provide the latest version of this tool, and Odoo requires you to use the latest version. Hence, we require to download the latest version from the Wkhtmltopdf website and install it. To do that, you may first visit the page:https://wkhtmltopdf.org/downloads.html

The page gives you the direct rpm download link for each version of CentOS/Ubuntu/Mac etc. Download the stable version for CentOS 7. At the time of writing, the URL for CentOS 7 x86_64 bit is the following:https://github.com/wkhtmltopdf/packaging/releases/download/0.12.6-1/wkhtmltox-0.12.6-1.centos7.x86_64.rpm

You may install this using the following:cd /opt/wget https://github.com/wkhtmltopdf/packaging/releases/download/0.12.6-1/wkhtmltox-0.12.6-1.centos7.x86_64.rpmyum localinstall wkhtmltox-0.12.6-1.centos7.x86_64.rpm

Install and Configure Odoo 13

If you have come all through here, that means you are done with the all dependency installations before starting to download Odoo 13 source code. We will download Odoo 13 from it’s Github repo and use virtualenv to create an isolated python environment to install this python software.

First, login as odoo from root:su – odoo

Clone the Odoo source code from Github repository:git clone https://www.github.com/odoo/odoo –depth 1 –branch 13.0 /opt/odoo/odoo13

This will bring the Odoo 13 branch from the Odoo repository and put it inside the folder /opt/odoo/odoo13

Now, we need to enable software collections in order to access python binaries:scl enable rh-python36 bash

Then we need to create a virtual environment to complete the installation:cd /opt/odoopython3 -m venv odoo13-venv

Now, you may activate the virtual environment you have just created:source odoo13-venv/bin/activate

Now, we upgrade the pip and install the wheel library:pip install –upgrade pippip3 install wheel

Once done, now we can using pip3 to install all the required Python modules from the requirements.txt file:pip3 install -r odoo13/requirements.txt

Once the installation is complete, now we can deactivate the virtual environment and get back to the root userdeactivate && exit ; exit

If you think, you will create custom modules, you may now create it and give odoo the permission accordingly:mkdir /opt/odoo/odoo13-custom-addonschown odoo: /opt/odoo/odoo13-custom-addons

Now, we can fill up the odoo configuration file. First open the odoo.conf file:nano /etc/odoo.conf

You may paste the following inside:[options]; This is the password that allows database operations:admin_passwd = set_the_password_to_create_odoo_databasedb_host = Falsedb_port = Falsedb_user = odoodb_password = Falseaddons_path = /opt/odoo/odoo13/addons,/opt/odoo/odoo13-custom-addons; You can enable log file with uncommenting the next line; logfile = /var/log/odoo13/odoo.log

Please do not forget to change the password ‘set_the_password_to_create_odoo_database’ with a new strong password. This would be used to create Odoo databases from the login screen.

Create the systemd service file and start Odoo 13

Now, we will create a service file, to be able to start, stop and restart Odoo daemon. To do that, first create a service file using the following:nano /etc/systemd/system/odoo13.service

and paste the following:[Unit]Description=Odoo13Requires=postgresql-9.6.serviceAfter=network.target postgresql-9.6.service[Service]Type=simpleSyslogIdentifier=odoo13PermissionsStartOnly=trueUser=odooGroup=odooExecStart=/usr/bin/scl enable rh-python35 — /opt/odoo/odoo13-venv/bin/python3 /opt/odoo/odoo13/odoo-bin -c /etc/odoo.confStandardOutput=journal+console[Install]WantedBy=multi-user.target

Now, save the file and exit.

Now, you need to reload the systemd daemon to be able to read the latest changes you have made to services. To do that, run:systemctl daemon-reload

Finally, now we can start Odoo 13 instance using the following command:systemctl start odoo13

If you are interested to check the status of the instance, you may do this:systemctl status odoo13[[email protected] ~]# systemctl status odoo13● odoo13.service – Odoo13 Loaded: loaded (/etc/systemd/system/odoo13.service; enabled; vendor preset: disabled) Active: active (running) since Sun 2020-09-13 08:26:46 EDT; 23h ago Main PID: 24502 (scl) CGroup: /system.slice/odoo13.service ├─24502 /usr/bin/scl enable rh-python36 — /opt/odoo/odoo13-venv/bin/python3 /opt/odoo/odoo13/odoo-bin -c /etc/odoo.conf ├─24503 /bin/bash /var/tmp/sclSWH04z └─24507 /opt/odoo/odoo13-venv/bin/python3 /opt/odoo/odoo13/odoo-bin -c /etc/odoo.conf

It show green active running, if everything worked out. If you see no error, you may now enable Odoo to start during the boot:systemctl enable odoo13

If you would like to see the logs, you may either use the journal tools like the following:journalctl -u odoo13

or uncomment the following line to log the debugs in /etc/odoo.conflogfile = /var/log/odoo13/odoo.log

After making any change to /etc/odoo.conf, do not forget the restart the Odoo13 instance using systemctl.

Test the Installation

You may now test the installation using http://your_server_ip:8069. If everything worked, it should come up. If it doesn’t, you may try stopping your ‘firewalld’ to see if firewall is blocking the port or not:

systemctl stop firewalld

At Mellowhost, we provide Odoo installation and configuration assistance for absolute free of charge. If you are willing to try out any of our VPS for Odoo, you may do so and talk with us through the Live chat or the ticket for Odoo assistance.

Furthermore, Good luck.

Server Boots to Grub – OVH Servers – How to Fix

Error Details

After you have completed updating your yum, you saw the kernel got updated, and hence restarted the server to take the new kernel. But you find out that the server has never come online. Once you visit the KVM or Serial Console (SOL) of the system, you could see, your system is booted to ‘grub>’ console instead of booting from disk. How can you fix the system now?

Solution Intro

This specific issue can appear for any linux server, along with many reasons. Although, if you are running an server from OVH and had faced a similar issue, the boat I am going to show you can navigate to destination. Please note, in many other case of similar situation, you might end up fixing the grub with the same solution.

What and How the Problem Happened

OVH has an interesting strategy of booting. They follow everything through network PXE, even if it is not ‘netboot’, but just the local drives. For this to work out, you need PXE to take the latest grub details pushed once a kernel is updated. This is one reason why, OVH also supplies a custom kernel from a cusstom repo. Although, if you are using the stock kernel, you might come up with a situation, where the latest grub hasn’t been pushed to PXE and your system fails to boot from drives. It then puts you in the ‘grub’ of network.

How to Fix the Problem

Now, one thing is clear, after you completed a kernel update, your grub is broken due to the latest machine code is not available to the booting system. You can go and follow a regular grub repair method for Grub 2, to fix the situation. A couple of things to remember, as your system’s grub is failing to load, you have to use an independent rescue kernel to fix this, this could either be from a personal network repository or a rescue disk available from your datacenter’s location, like ovh has one. Another thing to remember, is that, if you are using CentOS 7 or Ubuntu with UEFI system, using mdadm or linux software raid, it is highly likely, your boot efi is placed in a non raid partition. Preferably in the first drive’s first partition. You can always verify this from your fstab file.

So the first job, is to boot your system into the rescue disk/cd/kernel. I assume you have done that with no difficulty. Once done, first mount your partitions. In OVH cases, it loads the mdadm automatically. In my case, it was /dev/md2.

mount /dev/md2 /mnt
# check what partition is used for /boot/efi
nano /mnt/etc/fstab
# in my case, it is /dev/nvme0n1p1 (It is a NVMe SSD, and the first partion is used for efi storage
mount /dev/nvme0n1p1 /mnt/boot/efi

Once we have mounted the partitions successfully, you may now chroot the system. Before chrooting, you want the dev, proc and sys to use the /mnt partitions respectively:

mount --bind /dev /mnt/dev
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys

If these all goes well, now we can chroot the system:

chroot /mnt

Now you have successfully changed the root directory of the rescue kernel to the original drive’s root. All you need to do, is to remake the grub config, that will immediately generate the grub.cfg file and sync the machine code:

# we know grub.cfg is available in /boot/grub2/grub.cfg
grub2-mkconfig -o  /boot/grub2/grub.cfg
# once this is finished, we have to make sure, grub is also installed for both disks, for my case, these are /dev/nvme0n1 and /dev/nvme1n1
grub2-install /dev/nvme0n1
grub2-install /dev/nvme1n1

If you see the response is ‘No Error Reported’, then you are good go. You may now reboot your system back to hard disk, and can see your grub is able to load the latest kernel you installed from the original hard disk. Remember, for safety, you should umount all the partition, to avoid any data loss due to OS page cache:

# exit from chroot
exit
# unmount dev, proc, sys, /mnt/boot/efi, /mnt
umount /dev
umount /proc
umount /sys
umount /mnt/boot/efi
umount /mnt

Happy troubleshooting!

How to run composer with different PHP versions in Cpanel?

Question:

When we try to run a composer command, like update, we usually do the following:

composer update

Cpanel has multiple PHP binaries, but in this case, we are unable to select a specific PHP binary to use, instead we have to run it with the default one, how to run composer update with a different php binary in cpanel?

Solution

composer binary file, is a phar file. PHAR is necessarily a PHP Archive and usually automatically detect the running php. But as it is essentially written in php, you may explicitly run it with a different php binary, if you want. To run composer with different php binary, first, you need to find the location of composer. You may do so, using the following:

[email protected] [~]# which composer
/opt/cpanel/composer/bin/composer

Cpanel different php binaries are available under the following kind of directory:

/opt/cpanel/ea-phpXX/usr/bin/php

XX is the version number of PHP. So for example if you need to use PHP 7.4, you would need to run using the following:

/opt/cpanel/ea-php74/usr/bin/php

Now, to run composer update along with PHP 7.4 binary, you may do something like the following:

/opt/cpanel/ea-php74/usr/bin/php /opt/cpanel/composer/bin/composer update

First, make sure you are in the directory where you want to install laravel, for example, something like the following:

cd /home/username/public_html

Then, you may run the above command:

/opt/cpanel/ea-php74/usr/bin/php /opt/cpanel/composer/bin/composer update
or in case, you want to to install
/opt/cpanel/ea-php74/usr/bin/php /opt/cpanel/composer/bin/composer install
or may be, you wan to run update with no-scripts
/opt/cpanel/ea-php74/usr/bin/php /opt/cpanel/composer/bin/composer update --no-scripts

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.