Category Archives: System Administration

DNF Trying to Use SQLite Backend Warning

If you keep getting the following warning after upgrading to Fedora 33:

warning: Found bdb Packages database while attempting sqlite backend: using bdb backend.

Try rebuilding RPM database:

rpmdb --rebuilddb

If that results in:

error: can't create transaction lock on /var/lib/rpm/.rpm.lock (Permission denied)
Continue reading DNF Trying to Use SQLite Backend Warning

Silly but This Is a WordPress Blog Running on Kubernetes

You probably think it’s an overkill to use Kubernetes for a WordPress blog with less than a thousand monthly visitors. While this may be true, it’s totally worth using Kubernetes for the bragging rights. This is a WordPress blog running on Kubernetes!

Kubernetes running WordPress and MariaDB
Sources: https://pixabay.com/images/id-5718352/ and https://www.freepik.com/free-vector/cargo-freight-container_3795063.htm
Continue reading Silly but This Is a WordPress Blog Running on Kubernetes

Ultimate Way of Installing Metrics Server for Production Kubernetes Clusters

Metrics are very important in your Kubernetes cluster because you need them to monitor the pod resource usage. You also need metrics to trigger an autoscale using an Horizontal Pod Autoscaler (HPA). Metrics Server provides CPU and memory metrics so you can see them in Kubernetes Dashboard’s fancy graphs.

Kubernetes dashboard showing CPU and memory metrics in graphs
CPU and memory metrics in Kubernetes Dashboard
Continue reading Ultimate Way of Installing Metrics Server for Production Kubernetes Clusters

Inbound Firewall Configuration with Firewalld

Firewalld has replaced iptables as a default in many Linux distributions. It is now the default firewall in CentOS, Fedora, OpenSUSE, Red Hat Enterprise Linux, and SUSE Linux Enterprise. You can also install it on Debian and Ubuntu from their official package repositories.

Fire next to a wall
Image by Clker-Free-Vector-Images from Pixabay

Luckily firewall configuration with firewalld is very easy, especially for predefined services like http, https, ssh, etc.

Continue reading Inbound Firewall Configuration with Firewalld

What’s the best Kubernetes distribution for local environments?

There are plenty of Kubernetes distributions available that can be used to install Kubernetes locally. They tend to use minimal resources which is ideal. Question is what’s the best Kubernetes distribution for local use?

Local Kubernetes Distributions

This post contains benchmarks and reviews of the following Kubernetes distributions:

Continue reading What’s the best Kubernetes distribution for local environments?

Easy Backups to Google Drive on Linux

I’ve recently set up automated backups to Google Drive on my CentOS 7 Linux VPS to protect my blog posts from data loss. I don’t know why it took so long for me to care about backups of my own data. I chose to back up to Google Drive since I already have a Google One plan that has plenty of available storage space.

Screenshot from Google Drive showing 4 compressed files backed up in rclone/backup folder
Four compressed files backed up in a Google Drive folder
Continue reading Easy Backups to Google Drive on Linux

Single-node Kubernetes on Raspberry Pi

I’ve recently got a Raspberry Pi 4 Model B 8GB. I wanted to have one just to try running Kubernetes on Raspberry Pi. Most resources on the web seem to be for a huge cluster with a dozen nodes but I wanted to do it with a single node.

Picture of raspberry pi 4 with black case running
Raspberry Pi 4 Model B in its case

Operating system

As the operating system I chose  Ubuntu because of its Pi support even though I prefer Red Hat based distros.

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WordPress Backup Script

Recently I remembered that I had this little handy script that I used to backup my WordPress blog. The script contains only 2 actual commands.

I used nice while compressing / uncompressing the files to avoid CPU throttling since my blog is running on a shared hosting server.

This WordPress backup script doesn’t work without user interaction since it needs you to enter the password. Continue reading WordPress Backup Script