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Expose vs Publish ports in Docker

The general idea for communication between microservices (whatever is HTTP, message or event-driven communication) is related to certain protocols and ports on which each microservice...

In Docker, Dec 07, 2021

firewalld allow MySQL remote access

On most of the RHEL-based distributions, firewalld comes as a default firewall, and it’s configured to pass only SSH connections by default. Therefore, in this tutorial I’m going to s...

In Firewalls, MySQL, Dec 06, 2021

Disaster Recovery 101: RPO vs RTO

RPO (Recovery Point Objective) and RTO (Recovery Time Objective) are two of the most crucial and key parameters as part of a disaster recovery plan. Even though RTO and RPO sound alik...

In DR, Dec 05, 2021

How to install PHP Composer within Dockerfile

Dockerizing your PHP application probably would require some external commands within your base Docker image. That’s why you will need to have a Dockerfile and put all the additional ...

In Docker, PHP, Dec 04, 2021

How to list, renew and delete Certbot certificates

Managing Certbot certificates is often an underlooked operation since Certbot handles cert renewal automatically using a cronjob, so no worries there. But, what if we want to list whi...

In Certbot, Dec 03, 2021

How to install firewalld on Amazon Linux 2

Protecting your EC2 instance can be accomplished in multiple ways, setting up rules through the AWS security group or installing a firewall directly on your EC2 instance. Today I’m go...

In Firewalls, AWS, Amazon Linux 2, Dec 02, 2021

How to download files with curl

curl and wget are the most popular command-line tools (with curl being a library) for downloading remote content from the CLI. On one side, wget is simple to use as it gets, downloadi...

In Linux, macOS, Dec 01, 2021

How to install Firewalld on Rocky Linux 8

Keeping your services and host itself secure is crucial. Nowadays, there are a lot of attacks that can harm your host server, like brute force attacks, dictionary SSH attacks, SQL inj...

In Firewalls, Rocky Linux, Nov 30, 2021

How to shutdown and restart macOS from the Terminal

As a DevOps engineers, we must get used to running commands from the Terminal. Let’s see how easy and fast we can shutdown and restart a macOS machine after long day of work.

In macOS, Nov 29, 2021

How to secure domain with Let's Encrypt SSL/TLS certificate on Amazon Linux 2

As a sequel to the previous topic where we saw how to install Certbot on Amazon Linux 2, here I’m going to show you how to secure your domain with a free Let’s Encrypt SSL/TLS certifi...

In Let's Encrypt, AWS, Amazon Linux 2, Nov 28, 2021