[SOLVED] The following signatures were invalid: EXPKEYSIG B188E2B695BD4743 DEB.SURY.ORG Automatic Signing Key

Here is the solution if you've got the following error message when updating package lists on Debian (apt-get update): The following signatures were invalid: EXPKEYSIG B188E2B695BD4743 DEB.SURY.ORG Automatic Signing Key The sury.org Debian package repository has changed its package signing key. To fix the error, just download the new key: apt-key adv --fetch-keys https://packages.sury.org/php/apt.gpg Finally, ... Read more

PHP-FPM: php_value vs. php_admin_value directives explained

php_value vs. php_admin_value

php_admin_value and php_value are directives used in PHP-FPM (FastCGI Process Manager) configuration, often seen in context with web server setups like Apache or Nginx. They are used to set values for PHP's configuration directives e.g. in a PHP-FPM pool file or in the Apache server configuration. This is an alternative to changing PHP settings in ... Read more

Postfix Submission vs. Submissions (SMTPS) port

Postfix submission vs submissions port

In Postfix configuration, particularly on Debian and Ubuntu systems, you might come across terms like "submission" and "submissions" when looking into the Postfix /etc/postfix/master.cf file. This article explains the differences and use cases for both ports. Postfix Submission Port 587 This is the standard port for email submission as defined by the Internet Message Access ... Read more

How to enable port 587 (submission) in postfix

Postfix Port 587

pSome internet access providers have port 25 disabled in their routers to prevent spam. If you run your own email server in a data center, you might have to enable the submission port (587) in postfix to be able to send emails from your local email client to your own mail server. Enable Submission Port ... Read more

How to convert RPM software packages to Debian (.deb)

The world of Linux is diverse, Linux distributions using different package management systems. RPM (Red Hat Package Manager) and Debian's DEB are two of the most common package formats. Occasionally, users of Debian-based systems might need to install software that's only available in the RPM format. This guide covers converting RPM packages to DEB format, ... Read more

How to Restart a Docker Container

To restart a Docker container, you can use the docker restart command. This command stops and then starts the specified container. Here's a step-by-step guide on how to restart a Docker container, along with command examples: List Running Docker Containers As the first step, you need to identify the container you want to restart. To ... Read more