Tip

Learn about the creation and optimization of a CentOS 8 Stream Docker image, including steps to squash the image and ensure it is suitable for production workloads.

Discover the age and update frequency of various official Docker images, and learn why it’s important to keep your base images up to date for security and performance.

Learn how to debug memcached servers by sniffing network traffic to inspect commands, measure transfer rates, and analyze command frequencies using common Linux tools.

It happen to me all the time that one of developers notifies me about some kind of problem that I can’t confirm from my account. Sometimes it was because of bad ssh keys configuration, other times file permissions, mostly such stuff. It’s sometimes convenient to “enter into someone’s shoes” to see what’s going on there. If you’re root on machine you may do that like this: Switch to developer user su developer - Easy one but that’s not enough for all cases. When you use bastion host (or similar solutions) sometimes users have connection problems and it’s harder to check. When such user have ForwardAgent ssh option enabled you may stole this session to check login problems. ...

Virtualenvs in python are cheap but from time to time you will install something with pip on your system and when time comes removing all this crap could be difficult. I found this bash snippet1 that will uninstall package with all dependencies: Recursive pip uninstall for dep in $(pip show python-neutronclient | grep Requires | sed 's/Requires: //g; s/,//g') ; do pip uninstall -y $dep ; done pip uninstall -y python-neutronclient Depending how you installed it, you might need to use sudo. ...

A quick tip for forcing IPv4 connections in Linux when IPv6 causes issues with package managers or other services.

A quick tip on how to list files with their octal permissions in bash using the stat command.

I was configuring WordPress with HyperDB  external link plugin on PHP 7.0 but the only I get were constant 500 errors. As I found here  external link PHP 7.0 is not supported by HyperDB for now - it’s rely on mysql php extension but in PHP 7.0 there is only mysqli extension. But few folks fixed it and it’s possible to use it. ...

I’m playing a lot with Docker lately. Building images, and then rebuilding, and then building again… It’s pretty boring. To automate this task a little I used inotify to build automatically after I changed any file. This trick could be used in many different situations. On Linux You will need inotify-tools package: Install inotify-tools on Linux sudo apt-get install -y inotify-tools Then run something like this: ...

I’ve played with Docker a little in it early days but didn’t stick for longer with it. It’s stable now so I wanted to check how it’s running now. I really can’t accept this method of installation: curl -fsSL https://get.docker.com/ | sh I think that world is going to it’s end when I see such scritps… I prefer to do this manually, knowing exactly what I have to do. Install prerequisites: ...