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 …
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 …
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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 …
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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 …
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Replacing Xmarks cross-browser sync service with Eversync
I have a huge collection of bookmarks I collected over the years and I always have had the need to sync my bookmarks between my browsers of choice; Xmarks has always been one of the browser extensions I used for this need. Unfortunately, Xmarks is shutting down on May 1, 2018. I looked for some alternatives, like: …
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Automatically update your Docker base images with watchtower
I’m an avid user of Docker containers, using base images pulled from the public registry DockedHub. As you may know, Docker containers are based on Docked base images, e.g. I run postgres containers that are based on Postgres base image. It occurs that base images could get updated by their respective author (in our case Postgres team) and pushed to DockerHub. …
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Incubo PuntoCom Shop: NON acquistate su questo sito!
Recentemente ho acquistato un iPhone 8 sul sito PuntoCom Shop (linkato in nofollow). Dopo una settimana dall’acquisto, il telefono ha presentato un difetto con la fotocamera, scattando foto con un alone rosa; il difetto è conosciuto da Apple, tant’è che non sono l’unico ad essere stato vittima di questo difetto hardware Apple. Recandomi in un …
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Reverse engineer a Docker run command from an existing container
During my usual backup routine, I wanted to gather how a Docker container I started a while ago was run, especially the docker run command; this is required in case I need to re-run that container and I want to preserve the options (e.g. env variables, ports, etc.). Let’s make an example. I run a …
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Docker and containerd on openSUSE: reaching the limit for cgroup (and how to overcome it!)
I recently encountered a limitation during an experiment I was conducting; after some trial and error, I recognized that the limitation was due to cgroups. But let’s start from the beginning. I open sourced docker-salt, a small pet project I had in mind in order to have a full blown setup for SaltStack: a master …
Secure your SSH server against brute-force attacks with Fail2ban
The problem: SSH can be brute-forced I usually leave an SSH server on a dedicated port on every server I administer and, as you may recall, I even linked two well-written guides to properly configure and harden SSH services. Now, Internet is a notoriously bad place: scanners and exploiters have always been there, but brute-forcers …
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