Motivation I recently dealt with an application that is comprised of multiple services running in containers. Even though every part of this application is correctly split into each separated microservice, the independence of each service is not enforced. This lack of independence has several drawbacks, one of which is that containers must be started by … Continue reading Startup order in Docker containers
On servers timezone and tmux
A while ago I was fighting with a timezone set on a server because of the daylight saving time kicked in: during the ghost hour I had troubles with finding automated jobs. Moreover, the server was located overseas and depending on when I was checking the remote date and time, I could get a different … Continue reading On servers timezone and tmux
Automatic (or unattended) upgrades in openSUSE, CentOS and Fedora, Debian and Ubuntu
Each one of us is a system administrator: for at least your workstation (or notebook) you can decide when and how to administrate it. In the special case in which you are being elected to administer servers too, the matter becomes thorny: what is the workflow in terms of patching, time of reaction to security … Continue reading Automatic (or unattended) upgrades in openSUSE, CentOS and Fedora, Debian and Ubuntu
La mia esperienza con SPID e Poste Italiane
Questa settimana ho deciso di attivare lo SPID (Sistema Pubblico di Identità Digitale). Cosa è lo SPID L’identità digitale SPID è rappresentata da un username e una password che vi permettono di autenticarvi sui siti della Pubblica Amministrazione (PA). I suoi usi sono molteplici e sta prendendo sempre più piede per le comunicazioni online tra … Continue reading La mia esperienza con SPID e Poste Italiane
Send an email from a Docker container through an external MTA with ssmtp
I packaged a standard application (think of it as a standard PHP or <insert your preferred framework here>) into a Docker container. So far, it was working flawlessly, but then a problem arose: send an email from the Docker container (the event is triggered within the container). As you may know, a good Docker container … Continue reading Send an email from a Docker container through an external MTA with ssmtp
A comparison between browser features on desktop and mobile iOS
I am a long time user of Firefox and Chrome on desktops (GNU/Linux and macOS), while I rely on Chrome on my iOS devices. Recently there has been some valid critics of Chrome and its privacy choices and I began to look around for an alternative of Chrome. I identified a list of features that … Continue reading A comparison between browser features on desktop and mobile iOS
Linux: using bind mount to move a subset of root subdirectories to another partion or disk
I was in the situation dealing with a Linux box with two hard disks: /dev/sda: fast hard drive (SSD), small size (~200 GB) /dev/sdb: very big hard drive (HDD), large size (~4 TB) The operating system was installed on /dev/sda, so I had /dev/sdb empty. I knew I could create a mountpoint (e.g. /storage) and … Continue reading Linux: using bind mount to move a subset of root subdirectories to another partion or disk
Preventing Docker from manipulating iptables rules
By default, Docker manipulates iptables rules to provide network isolation: Chain FORWARD (policy DROP) target prot opt source destination DOCKER all — 0.0.0.0/0 0.0.0.0/0 […] Chain DOCKER (1 references) target prot opt source destination I don’t mind having my iptables rules for forwarding manipulated, but there is a caveat: when you expose a container (with … Continue reading Preventing Docker from manipulating iptables rules
Automatically add SSH keys to SSH agent with GNOME and macOS
I am using passwordless login via SSH on every box that I administer. Of course, my private SSH key is protected with a password that must be provided when accessing the key. Modern operating systems incorporate the usage of ssh-agent to “link” the user account to the SSH key(s), in order to unlock the SSH … Continue reading Automatically add SSH keys to SSH agent with GNOME and macOS
Accessing remote libvirt on a non-standard SSH port via virt-manager
Scenario: you are using a remote host as a virtualization host with libvirt and you want to manage it via ”Virtual machine manager” (virt-manager) over SSH. But SSH is listening on a non-standard port, and virt-manager does not offer you to connect to a remote libvirt instance on a non-standard port. Fear not, the option … Continue reading Accessing remote libvirt on a non-standard SSH port via virt-manager