Linux

You’ll probably know Pi-hole. It’s a popular “DNS sinkhole” – a DNS proxy server which blocks certain requests, such a as those for well-known ad serving domains. The effect is a much less ad-cluttered web experience in your home network. I’ve been using Pi-hole for several years as a Docker container on a Raspberry Pi. The Raspi is serving as a small home server on my home network. However, as much as I like Pi-hole, I felt it got loaded with new features over the years and performed slower over the time....

In June, I’ve written about my approach to starting and stopping Podman Pods using OpenRC scripts on Alpine Linux. However, that approach had two major drawbacks: First, the pods were started in the foreground, causing OpenRC to wait for all pod initialization tasks to complete. If an image needed to be pulled first, this could lead to longer delays, significantly increasing system startup times. Secondly, requesting the status of a previously started pod always stated “crashed”....

I’m running my containers with Podman in Rootless Mode on Alpine for about four months now. However, an annoying problem has haunted me ever since: When a container was connected to more than one network, outgoing connections were not working correctly. Consider a container connected to two bridge networks: $ podman run --rm -it \ --network net1 \ --network net2 \ alpine /bin/ash Inside the container, the two networks are connected correctly:...

Recently, I’ve written a blog post on how to set up Rootless Docker on Alpine Linux. Today I’m showing you how to set up Podman. Podman has a rootless architecture built in. It’s an alternative to Docker, providing an almost identical command line interface. Thus, if you’re used to Docker CLI, you won’t have any issues working with Podman. Podman was initially developed by RedHat and is available as an open source project....

As of Docker Engine v20.10, it’s possible to run the Docker daemon as a non-root user (Rooless mode). This is especially valuable in view of security aspects. Rootless mode mitigates potential vulnerabilities in the Docker daemon. However, at the time of writing, setting up Docker in rootless mode is not straightforward if you’re using Alpine Linux as your host system. This is why I summarized the steps to get Docket Rootless up and running on Alpine Linux....

Several months ago, I wrote a blog post about reducing a PDF file’s size. Since then, I’ve used that technique many times. However, you may want to control the DPI (dots per inch) even more specific. Here’s how to do it: gs -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.7 \ -dDownsampleColorImages=true \ -dDownsampleGrayImages=true \ -dDownsampleMonoImages=true \ -dColorImageResolution=120 \ -dGrayImageResolution=120 \ -dMonoImageResolution=120 \ -sOutputFile=output.pdf input.pdf Hint: This also works on MacOS. Just install GhostScript using Homebrew:...

Using a single line of GhostScript command on my Ubuntu’s terminal, I was able to reduce the size of a PDF file from 6 MB to approximately 1 MB: gs -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -sOutputFile=output.pdf input.pdf You can also use the following parameters for -dPDFSETTINGS instead of /screen: /screen – Lowest quality, lowest size /ebook – Moderate quality /printer – Good quality /prepress – Best quality, highest size Update: Read Part 2 of this blog post for more detailled file size reduction settings....