Kubernetes on Fedora IoT with k3s

Fedora IoT is an upcoming Fedora edition targeted at the Internet of Things. It was introduced last year on Fedora Magazine in the article How to turn on an LED with Fedora IoT. Since then, it has continued to improve together with Fedora Silverblue to provide an immutable base operating system aimed at container-focused workflows.

Kubernetes is an immensely popular container orchestration system. It is perhaps most commonly used on powerful hardware handling huge workloads. However, it can also be used on lightweight devices such as the Raspberry Pi 3. Read on to find out how.

Why Kubernetes?

While Kubernetes is all the rage in the cloud, it may not be immediately obvious to run it on a small single board computer. But there are certainly reasons for doing it. First of all it is a great way to learn and get familiar with Kubernetes without the need for expensive hardware. Second, because of its popularity, there are tons of applications that comes pre-packaged for running in Kubernetes clusters. Not to mention the large community to provide help if you ever get stuck.

Last but not least, container orchestration may actually make things easier, even at the small scale in a home lab. This may not be apparent when tackling the the learning curve, but these skills will help when dealing with any cluster in the future. It doesn’t matter if it’s a single node Raspberry Pi cluster or a large scale machine learning farm.

K3s – a lightweight Kubernetes

A “normal” installation of Kubernetes (if such a thing can be said to exist) is a bit on the heavy side for IoT. The recommendation is a minimum of 2 GB RAM per machine! However, there are plenty of alternatives, and one of the newcomers is k3s – a lightweight Kubernetes distribution.

K3s is quite special in that it has replaced etcd with SQLite for its key-value storage needs. Another thing to note is that k3s ships as a single binary instead of one per component. This diminishes the memory footprint and simplifies the installation. Thanks to the above, k3s should be able to run k3s with just 512 MB of RAM, perfect for a small single board computer!

What you will need

  1. Fedora IoT in a virtual machine or on a physical device. See the excellent getting started guide here. One machine is enough but two will allow you to test adding more nodes to the cluster.
  2. Configure the firewall to allow traffic on ports 6443 and 8472. Or simply disable it for this experiment by running “systemctl stop firewalld”.

Install k3s

Installing k3s is very easy. Simply run the installation script:

curl -sfL https://get.k3s.io | sh -

This will download, install and start up k3s. After installation, get a list of nodes from the server by running the following command:

kubectl get nodes

Note that there are several options that can be passed to the installation script through environment variables. These can be found in the documentation. And of course, there is nothing stopping you from installing k3s manually by downloading the binary directly.

While great for experimenting and learning, a single node cluster is not much of a cluster. Luckily, adding another node is no harder than setting up the first one. Just pass two environment variables to the installation script to make it find the first node and avoid running the server part of k3s

curl -sfL https://get.k3s.io | K3S_URL=https://example-url:6443 \
K3S_TOKEN=XXX sh -

The example-url above should be replaced by the IP address or fully qualified domain name of the first node. On that node the token (represented by XXX) is found in the file /var/lib/rancher/k3s/server/node-token.

Deploy some containers

Now that we have a Kubernetes cluster, what can we actually do with it? Let’s start by deploying a simple web server.

kubectl create deployment my-server --image nginx

This will create a Deployment named “my-server” from the container image “nginx” (defaulting to docker hub as registry and the latest tag). You can see the Pod created by running the following command.

kubectl get pods

In order to access the nginx server running in the pod, first expose the Deployment through a Service. The following command will create a Service with the same name as the deployment.

kubectl expose deployment my-server --port 80

The Service works as a kind of load balancer and DNS record for the Pods. For instance, when running a second Pod, we will be able to curl the nginx server just by specifying my-server (the name of the Service). See the example below for how to do this.

# Start a pod and run bash interactively in it
kubectl run debug --generator=run-pod/v1 --image=fedora -it -- bash
# Wait for the bash prompt to appear
curl my-server
# You should get the "Welcome to nginx!" page as output

Ingress controller and external IP

By default, a Service only get a ClusterIP (only accessible inside the cluster), but you can also request an external IP for the service by setting its type to LoadBalancer. However, not all applications require their own IP address. Instead, it is often possible to share one IP address among many services by routing requests based on the host header or path. You can accomplish this in Kubernetes with an Ingress, and this is what we will do. Ingresses also provide additional features such as TLS encryption of the traffic without having to modify your application.

Kubernetes needs an ingress controller to make the Ingress resources work and k3s includes Traefik for this purpose. It also includes a simple service load balancer that makes it possible to get an external IP for a Service in the cluster. The documentation describes the service like this:

k3s includes a basic service load balancer that uses available host ports. If you try to create a load balancer that listens on port 80, for example, it will try to find a free host in the cluster for port 80. If no port is available the load balancer will stay in Pending.

k3s README

The ingress controller is already exposed with this load balancer service. You can find the IP address that it is using with the following command.

$ kubectl get svc --all-namespaces
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
default kubernetes ClusterIP 10.43.0.1 443/TCP 33d
default my-server ClusterIP 10.43.174.38 80/TCP 30m
kube-system kube-dns ClusterIP 10.43.0.10 53/UDP,53/TCP,9153/TCP 33d
kube-system traefik LoadBalancer 10.43.145.104 10.0.0.8 80:31596/TCP,443:31539/TCP 33d

Look for the Service named traefik. In the above example the IP we are interested in is 10.0.0.8.

Route incoming requests

Let’s create an Ingress that routes requests to our web server based on the host header. This example uses xip.io to avoid having to set up DNS records. It works by including the IP adress as a subdomain, to use any subdomain of 10.0.0.8.xip.io to reach the IP 10.0.0.8. In other words, my-server.10.0.0.8.xip.io is used to reach the ingress controller in the cluster. You can try this right now (with your own IP instead of 10.0.0.8). Without an ingress in place you should reach the “default backend” which is just a page showing “404 page not found”.

We can tell the ingress controller to route requests to our web server Service with the following Ingress.

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: my-server
spec:
rules:
- host: my-server.10.0.0.8.xip.io
http:
paths:
- path: /
backend:
serviceName: my-server
servicePort: 80

Save the above snippet in a file named my-ingress.yaml and add it to the cluster by running this command:

kubectl apply -f my-ingress.yaml

You should now be able to reach the default nginx welcoming page on the fully qualified domain name you chose. In my example this would be my-server.10.0.0.8.xip.io. The ingress controller is routing the requests based on the information in the Ingress. A request to my-server.10.0.0.8.xip.io will be routed to the Service and port defined as backend in the Ingress (my-server and 80 in this case).

What about IoT then?

Imagine the following scenario. You have dozens of devices spread out around your home or farm. It is a heterogeneous collection of IoT devices with various hardware capabilities, sensors and actuators. Maybe some of them have cameras, weather or light sensors. Others may be hooked up to control the ventilation, lights, blinds or blink LEDs.

In this scenario, you want to gather data from all the sensors, maybe process and analyze it before you finally use it to make decisions and control the actuators. In addition to this, you may want to visualize what’s going on by setting up a dashboard. So how can Kubernetes help us manage something like this? How can we make sure that Pods run on suitable devices?

The simple answer is labels. You can label the nodes according to capabilities, like this:

kubectl label nodes <node-name> <label-key>=<label-value>
# Example
kubectl label nodes node2 camera=available

Once they are labeled, it is easy to select suitable nodes for your workload with nodeSelectors. The final piece to the puzzle, if you want to run your Pods on all suitable nodes is to use DaemonSets instead of Deployments. In other words, create one DaemonSet for each data collecting application that uses some unique sensor and use nodeSelectors to make sure they only run on nodes with the proper hardware.

The service discovery feature that allows Pods to find each other simply by Service name makes it quite easy to handle these kinds of distributed systems. You don’t need to know or configure IP addresses or custom ports for the applications. Instead, they can easily find each other through named Services in the cluster.

Utilize spare resources

With the cluster up and running, collecting data and controlling your lights and climate control you may feel that you are finished. However, there are still plenty of compute resources in the cluster that could be used for other projects. This is where Kubernetes really shines.

You shouldn’t have to worry about where exactly those resources are or calculate if there is enough memory to fit an extra application here or there. This is exactly what orchestration solves! You can easily deploy more applications in the cluster and let Kubernetes figure out where (or if) they will fit.

Why not run your own NextCloud instance? Or maybe gitea? You could also set up a CI/CD pipeline for all those IoT containers. After all, why would you build and cross compile them on your main computer if you can do it natively in the cluster?

The point here is that Kubernetes makes it easier to make use of the “hidden” resources that you often end up with otherwise. Kubernetes handles scheduling of Pods in the cluster based on available resources and fault tolerance so that you don’t have to. However, in order to help Kubernetes make reasonable decisions you should definitely add resource requests to your workloads.

Summary

While Kubernetes, or container orchestration in general, may not usually be associated with IoT, it certainly makes a lot of sense to have an orchestrator when you are dealing with distributed systems. Not only does is allow you to handle a diverse and heterogeneous fleet of devices in a unified way, but it also simplifies communication between them. In addition, Kubernetes makes it easier to utilize spare resources.

Container technology made it possible to build applications that could “run anywhere”. Now Kubernetes makes it easier to manage the “anywhere” part. And as an immutable base to build it all on, we have Fedora IoT.

Command line quick tips: Cutting content out of files

The Fedora distribution is a full featured operating system with an excellent graphical desktop environment. A user can point and click their way through just about any typical task easily. All of this wonderful ease of use masks the details of a powerful command line under the hood. This article is part of a series that shows you some common command line utilities. So let’s drop into the shell, and have a look at cut.

Often when you work in the command line, you are working with text files. Sometimes these files may be quite long. Reading them in their entirety, while feasible, can be time consuming and prone to errors. In this installment you’ll learn how to extract content from text files, and get the information you want from them.

It’s important to recognize that there are many ways to accomplish similar command line tasks in Fedora. The Fedora repositories include entire language systems for parsing and working with text, as an example. Also, there are multiple command line utilities available for just about any purpose conceivable in the shell. This article will only focus on using a few of those utility choices, to extract some information from a file and present it in a readable format.

Making the cut

To illustrate this example use a standard sizable file on the system like /etc/passwd. As seen in a prior article in this series, you can execute the cat command to view an entire file:

$ cat /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
...

This file contains information on all accounts present on the system. It has a specific format:

name:password:user-id:group-id:comment:home-directory:shell

Imagine that you want to simply have a list of all the account names on the system. If you could only cut out the name value from each line. This is where the cut command comes in handy! This command treats any input one line at a time, and extracts a specific part of the line.

The cut command provides options for selecting parts of a line differently, and in this example two of them are needed, -d which is an option to specify a delimiter type to use, and -f which is an option to specify which field of the line to cut. The -d option lets you declare the delimiter that separates values in a line. In this case a colon (:) is used to separate values. The -f option lets you choose which field value or values to extract. So for this example the command entered would be:

$ cut -d: -f1 /etc/passwd
root
bin
daemon
adm
...

That’s great, it worked! But you get the printout to the standard output, which in a terminal session at least means the screen. What if you needed the information for another task to be done later? It would be really nice if there was a way to put the output of the cut command into a text file to save it. There is an easy builtin shell function for such a task, the redirect function (>).

$ cut -d: -f1 /etc/passwd > names.txt

This will place the output of cut into a file called names.txt and you can check the contents with cat:

$ cat names.txt
root
bin
daemon
adm
...

With two commands and one shell function, it was easy to identify using cat, extract using cut, and redirect the extracted information from one file, saving it to another file for later use.


Photo by Joel Mbugua on Unsplash.

3 cool text-based email clients

Writing and receiving email is a big part of everyone’s daily routine and choosing an email client is usually a major decision. The Fedora OS provides a large choice of email clients and among these are text-based email applications.

Mutt

Mutt is probably one of the most popular text-based email clients. It supports all the common features that one would expect from an email client. Color coding, mail threading, POP3, and IMAP are all supported by Mutt. But one of its best features is it’s highly configurable. Indeed, the user can easily change the keybindings, and create macros to adapt the tool to a particular workflow.

To give Mutt a try, install it using sudo and dnf:

$ sudo dnf install mutt

To help newcomers get started, Mutt has a very comprehensive wiki full of macro examples and configuration tricks.

Alpine

Alpine is also among the most popular text-based email clients. It’s more beginner friendly than Mutt, and you can configure most of Alpine via the application itself — no need to edit a configuration file. One powerful feature of Alpine is the ability to score emails. This is particularly interesting for users that are registered to a high volume mailing list like Fedora’s devel list. Using scores, Alpine can sort the email based on the user’s interests, showing emails with a high score first.

Alpine is also available to install from Fedora’s repository using dnf.

 $ sudo dnf install alpine

While using Alpine, you can easily access the documentation by pressing the Ctrl+G key combination.

nmh

nmh (new Mail Handling) follows the UNIX tools philosophy. It provides a collection of single purpose programs to send, receive, save, retrieve, and manipulate e-mail messages. This lets you swap the nmh command with other programs, or create scripts around nmh to create more customized tools. For example, you can use Mutt with nmh.

nmh can be easily installed using dnf.

$ sudo dnf install nmh

To learn more about nmh and mail handling in general you can read this GPL licenced book.

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Let’s try dwm — dynamic window manger

If you like efficiency and minimalism, and are looking for a new window manager for your Linux desktop, you should try dwm — dynamic window manager. Written in under 2000 standard lines of code, dwm is extremely fast yet powerful and highly customizable window manager.

You can dynamically choose between tiling, monocle and floating layouts, organize your windows into multiple workspaces using tags, and quickly navigate through using keyboard shortcuts. This article helps you get started using dwm.

Installation

To install dwm on Fedora, run:

$ sudo dnf install dwm dwm-user

The dwm package installs the window manager itself, and the dwm-user package significantly simplifies configuration which will be explained later in this article.

Additionally, to be able to lock the screen when needed, we’ll also install slock — a simple X display locker.

$ sudo dnf install slock

However, you can use a different one based on your personal preference.

Quick start

To start dwm, choose the dwm-user option on the login screen.

After you log in, you’ll see a very simple desktop. In fact, the only thing there will be a bar at the top listing our nine tags that represent workspaces and a []= symbol that represents the layout of your windows.

Launching applications

Before looking into the layouts, first launch some applications so you can play with the layouts as you go. Apps can be started by pressing Alt+p and typing the name of the app followed by Enter. There’s also a shortcut Alt+Shift+Enter for opening a terminal.

Now that some apps are running, have a look at the layouts.

Layouts

There are three layouts available by default: the tiling layout, the monocle layout, and the floating layout.

The tiling layout, represented by []= on the bar, organizes windows into two main areas: master on the left, and stack on the right. You can activate the tiling layout by pressing Alt+t.

The idea behind the tiling layout is that you have your primary window in the master area while still seeing the other ones in the stack. You can quickly switch between them as needed.

To swap windows between the two areas, hover your mouse over one in the stack area and press Alt+Enter to swap it with the one in the master area.

The monocle layout, represented by [N] on the top bar, makes your primary window take the whole screen. You can switch to it by pressing Alt+m.

Finally, the floating layout lets you move and resize your windows freely. The shortcut for it is Alt+f and the symbol on the top bar is ><>.

Workspaces and tags

Each window is assigned to a tag (1-9) listed at the top bar. To view a specific tag, either click on its number using your mouse or press Alt+1..9. You can even view multiple tags at once by clicking on their number using the secondary mouse button.

Windows can be moved between different tags by highlighting them using your mouse, and pressing Alt+Shift+1..9. 

Configuration

To make dwm as minimalistic as possible, it doesn’t use typical configuration files. Instead, you modify a C header file representing the configuration, and recompile it. But don’t worry, in Fedora it’s as simple as just editing one file in your home directory and everything else happens in the background thanks to the dwm-user package provided by the maintainer in Fedora.

First, you need to copy the file into your home directory using a command similar to the following:

$ mkdir ~/.dwm
$ cp /usr/src/dwm-VERSION-RELEASE/config.def.h ~/.dwm/config.h

You can get the exact path by running man dwm-start.

Second, just edit the ~/.dwm/config.h file. As an example, let’s configure a new shortcut to lock the screen by pressing Alt+Shift+L.

Considering we’ve installed the slock package mentioned earlier in this post, we need to add the following two lines into the file to make it work:

Under the /* commands */ comment, add:

static const char *slockcmd[] = { "slock", NULL };

And the following line into static Key keys[]:

{ MODKEY|ShiftMask, XK_l, spawn, {.v = slockcmd } },

In the end, it should look like as follows: (added lines are highlighted)

...
/* commands */
static char dmenumon[2] = "0"; /* component of dmenucmd, manipulated in spawn() */
static const char *dmenucmd[] = { "dmenu_run", "-m", dmenumon, "-fn", dmenufont, "-nb", normbgcolor, "-nf", normfgcolor, "-sb", selbgcolor, "-sf", selfgcolor, NULL };
static const char *termcmd[]  = { "st", NULL };
static const char *slockcmd[] = { "slock", NULL };

static Key keys[] = {
/* modifier                     key        function        argument */
{ MODKEY|ShiftMask,             XK_l,      spawn,          {.v = slockcmd } },
{ MODKEY,                       XK_p,      spawn,          {.v = dmenucmd } },
{ MODKEY|ShiftMask,             XK_Return, spawn,          {.v = termcmd } },
...

Save the file.

Finally, just log out by pressing Alt+Shift+q and log in again. The scripts provided by the dwm-user package will recognize that you have changed the config.h file in your home directory and recompile dwm on login. And becuse dwm is so tiny, it’s fast enough you won’t even notice it.

You can try locking your screen now by pressing Alt+Shift+L, and then logging back in again by typing your password and pressing enter.

Conclusion

If you like minimalism and want a very fast yet powerful window manager, dwm might be just what you’ve been looking for. However, it probably isn’t for beginners. There might be a lot of additional configuration you’ll need to do in order to make it just as you like it.

To learn more about dwm, see the project’s homepage at https://dwm.suckless.org/.

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Building Flatpak apps in Gnome Builder on Fedora Silverblue

If you are developing software using Fedora Silverblue, and especially if what you are developing is a Gnome application, Gnome Builder 3.30.3 feels like an obvious choice of IDE.

In this article, I will show you how you can create a simple Gnome application, and how to build it and install it as a Flatpak app on your system.

Gnome and Flatpak applications

Builder has been a part of Gnome for a long time. It is a very mature IDE to me in terms of consistency and completeness.

The Gnome Builder project website offers extensive documentation regarding Gnome application development — I highly recommend spending some time there to anyone interested.

Editor’s note: Getting Builder

Because the initial Fedora Silverblue installation doesn’t include Builder, let’s walk through the installation process first.

Starting with a freshly installed system, the first thing you’ll need to do is to enable a repository providing Builder as a Flatpak — we’ll use Flathub which is a popular 3rd-party repository with many desktop apps.

To enable Flathub on your system, download the repository file from the Fedora Quick Setup page, and double-click it which opens Gnome Software asking you to enable this repository on your system.

After you’re done with that, you can search for Builder in Gnome Software and install it.

Creating a new project

So let’s walk through the creation of a new project for our Gnome app. When you start Gnome Builder, the first display is oriented towards project management.

To create a new project, I clicked on the New… button at the top-left corner which showed me the following view.

You’ll need to fill out the project name, choose your preferred language (I chose C, but other languages will work for this example as well), and the license. Leave the version control on, and select Gnome Application as your template.

I chose gbfprtfsb as the name of my project which means Hello from Gnome 3 on Fedora SilverBlue.

The IDE creates and opens the project once you press create.

Tweaking our new project

The newly created project is opened in the Builder IDE and on my system looks like the following.

This project could be run from within the IDE right now and would give you the ever popular “Hello World!” titled gnome windowed application with a label that says, yup “Hello World!”.

Let’s get a little disruptive and mess up the title and greeting a bit. Complacency leads to mediocrity which leads to entropy overcoming chaos to enforce order, stasis, then finally it all just comes to a halt. It’s therefore our duty to shake it up at every opportunity, if only to knock out any latent entropy that may have accumulated in our systems. Towards such lofty goals, we only need to change two lines of one file, and the file isn’t even a C language file, it’s an XML file used to describe the GUI named gbfprtfsb-window.ui. All we have to do is open it and edit the title and label text, save and then build our masterpiece!

Looking at the screenshot below, I have circled the text we are going to replace. The window is a GtkApplicationWindow, and uses a GtkHeaderBar and GtkLabel to display the text we are changing. In the GtkHeaderBar we will type GBFPRTFSB for the title property. In the GtkLabel we will type Hello from Gnome 3 on Fedora SilverBlue in the label property. Now save the file to record our changes.

Building the project

Well, we have made our changes, and expressed our individualism (cough) at the same time. All that is left is to build it and see what it looks like. The build panel is located near the top of the IDE, middle right, and is represented by the icon that appears to be a brick wall being built as shown on the following picture.

Press the button, and the build process completes. You can also preview your application by clicking on the “play” button next to it.

Building a Flatpak

When we’re happy with our creation, the next step will be building it as a Flatpak. To do that, click on the title in the middle of the top bar, and then on the Export Bundle button.

Once the export has successfully completed, Gnome Builder will open a Nautilus file browser window showing the export directory, with the Flatpak bundle already selected.

To install the app on your system, simply double-click the icon which opens Gnome Software allowing you to install the app. On my system I had to enter my user password twice, which I take to be due to the fact we had no configured GPG key for the project. After it was installed, the application was shown alongside all of the other applications on my system. It can be seen running below.

I think this has successfully shown how easy it is to deploy an application as a Flatpak bundle for Gnome using Builder, and then running it on Fedora Silverblue.

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Convert your Fedora Silverblue to HTPC with Kodi

Ever wanted to create a HTPC from old computer laying around. Or just have some spare time and want to try something new. This article could be just for you. It will show you the step by step process to convert a Fedora Silverblue to a fully fledged HTPC.

What is Fedora Silverblue, Kodi and HTPC?

Fedora Silverblue is a system similar to Fedora Workstation. It offers an immutable filesystem (only /var and /etc are writable) and atomic updates using an ostree image, which offers reliable updates with ability to rollback to previous version easily. If you want to find out more about Fedora Silverblue visit https://silverblue.fedoraproject.org/ or if you want to try it by yourself you can get it here.

Kodi is one of the best multimedia player available. It provides plenty of features (like automatic downloads of metadata for movies, support for UPnP etc.) and it’s open source. It also has many addons. So if you are missing any functionality you could probably find an addon for it.

HTPC is just an acronym for Home Theater PC in simple words a PC that is mainly used as an entertainment station. You can connect it to TV or any monitor and just use it to watch your favorite movies, TV shows or listen to your favorite music.

Why choosing Silverblue to create an HTPC?

So why choosing Fedora Silverblue for HTPC? The main reasons are:

  • Reliability – you don’t need to fear that after update everything stop working and if it does, I can rollback easily
  • New technology – it is a good opportunity to play with a new technology.

And why to choose Kodi ? As stayted before it’s one of the best multimedia player and it’s packaged as a flatpak, which make it easy to install on Silverblue.

Conversion of Fedora Silverblue to HTPC

Let’s go step by step through this process and see how to create a fully usable HTPC from Fedora Silverblue.

1. Installation of Fedora Silverblue

First thing you need to do is to install Fedora Silverblue, this guide will not cover the installation process, but you can expect similar process as with standard Fedora Workstation installation. You can get the Fedora Silverblue ISO here

Create only the root user during the installation with some password. We will create a user for Kodi later without password.

2. Booting to terminal

This part will be a little tricky. You need to bypass GNOME and end the boot sequence in terminal. Otherwise you will end up in GNOME initial setup process, which will not allow you to create user without password.

To bypass the GNOME you need to press the ‘e’ key in GRUB menu to edit the GRUB entry. When editing the GRUB entry just look for the line starting with linux16 and add 3 to end of this line. Then continue the boot sequence with CTRL + x. Don’t worry about the changes, they are used only for this session.

GRUB menu
GRUB entry edited

You will end up in terminal where you need to login as root.

3. Creation of user for Kodi

When you are in the terminal logged as root, you need to create a user that will be used by Kodi. This can be done using the useradd command.

useradd kodi

4. Installation of Kodi from Flathub

To install the Kodi in flatpak you first need to add a Flathub remote repository.

flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

With the Flathub repository added the installation of Kodi is simple.

flatpak install flathub tv.kodi.Kodi

5. Set Kodi as autostart application

First we need to create the autostart directory for the kodi user, this is easier if you switch to kodi user directly.

su kodi
mkdir -p /home/kodi/.config/autostart

Then you need to create a symlink for the Kodi desktop file.

ln -s /var/lib/flatpak/exports/share/applications/tv.kodi.Kodi.desktop /home/kodi/.config/autostart/tv.kodi.Kodi.desktop

The last thing that will prevent for autostart to work correctly is the GNOME initial setup. To disable it just create a gnome-initial-setup-done file in .config directory of kodi user.

echo "yes" > /home/kodi/.config/gnome-initial-setup-done

You can now switch back to root for the next steps.

exit

6. Set autologin for kodi user

This step is very useful together with autostart of Kodi. Every time you restart your HTPC you will end up directly in Kodi and not in the GDM or GNOME shell. To set the auto login you need to add the following lines to /etc/gdm/custom.conf to the [daemon] section

AutomaticLoginEnable=True 
AutomaticLogin=kodi

7. Enable automatic updates

For HTPC automatic updates you will need a cron job. But because cron is not part of the standard Fedora Silverblue installation you need to install it first. In this step I also recommend to do upgrade of the Fedora Silverblue first before layering the cron package.

rpm-ostree upgrade

rpm-ostree install cronie

After this you need to reboot your computer, to apply the new updates.

reboot

To be able to setup cron in this phase you need to do the second step again and log in as root. After this you need to edit the crontab.

crontab -e

And add the following line to it.

0 4 * * 3 flatpak update -y; rpm-ostree upgrade; reboot

This will create a new cron job, which will update any flatpaks (Kodi in this case), update Silverblue and does a restart to apply the changes.

This job will run at 4 AM on Wednesday. It is recommended to set this to a time when nobody will use the HTPC.

Restart the computer now.

reboot

8. Disable GNOME features

There are few GNOME features that could be annoying when using Fedora Silverblue as HTPC. Most of these features could be setup directly in Kodi anyway, so if you want them later it’s easy to set them directly in Kodi.

To do this exit Kodi and open the terminal. Press Super key (this is the key between ALT and CTRL) and type terminal. Once the terminal will be open and you need to type the following commands.

# Display dim
dconf write "/org/gnome/settings-daemon/plugins/power/idle-dim" false

# Sleep over time/
dconf write "/org/gnome/settings-daemon/plugins/power/sleep-inactive-ac-type" 0

# Screensaver
dconf write "/org/gnome/desktop/screensaver/lock-enabled" false

# Automatic updates through gnome-software
dconf write "/org/gnome/software/download-updates" false

And that’s it, you just need to do one last restart to apply the dconf changes. After the restart you will end up directly in Kodi.

Kodi

What now?

Now I will recommend you to play with the Kodi settings a little bit and set it up to your liking. You can find plenty of guides on the internet.

If you want to automate the process you can use my ansible script that was written just for this occasion.


Photo by Sven Scheuermeier on Unsplash

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4 cool new projects to try in COPR for February 2019

COPR is a collection of personal repositories for software that isn’t carried in Fedora. Some software doesn’t conform to standards that allow easy packaging. Or it may not meet other Fedora standards, despite being free and open source. COPR can offer these projects outside the Fedora set of packages. Software in COPR isn’t supported by Fedora infrastructure or signed by the project. However, it can be a neat way to try new or experimental software.

Here’s a set of new and interesting projects in COPR.

CryFS

CryFS is a cryptographic filesystem. It is designed for use with cloud storage, mainly Dropbox, although it works with other storage providers as well. CryFS encrypts not only the files in the filesystem, but also metadata, file sizes and directory structure.

Installation instructions

The repo currently provides CryFS for Fedora 28 and 29, and for EPEL 7. To install CryFS, use these commands:

sudo dnf copr enable fcsm/cryfs
sudo dnf install cryfs

Cheat

Cheat is a utility for viewing various cheatsheets in command-line, aiming to help remind usage of programs that are used only occasionally. For many Linux utilities, cheat provides cheatsheets containing condensed information from man pages, focusing mainly on the most used examples. In addition to the built-in cheatsheets, cheat allows you to edit the existing ones or creating new ones from scratch.

Installation instructions

The repo currently provides cheat for Fedora 28, 29 and Rawhide, and for EPEL 7. To install cheat, use these commands:

sudo dnf copr enable tkorbar/cheat
sudo dnf install cheat

Setconf

Setconf is a simple program for making changes in configuration files, serving as an alternative for sed. The only thing setconf does is that it finds the key in the specified file and changes its value. Setconf provides only a few options to change its behavior — for example, uncommenting the line that is being changed.

Installation instructions

The repo currently provides setconf for Fedora 27, 28 and 29. To install setconf, use these commands:

sudo dnf copr enable jamacku/setconf
sudo dnf install setconf

Reddit Terminal Viewer

Reddit Terminal Viewer, or rtv, is an interface for browsing Reddit from terminal. It provides the basic functionality of Reddit, so you can log in to your account, view subreddits, comment, upvote and discover new topics. Rtv currently doesn’t, however, support Reddit tags.

Installation instructions

The repo currently provides Reddit Terminal Viewer for Fedora 29 and Rawhide. To install Reddit Terminal Viewer, use these commands:

sudo dnf copr enable tc01/rtv
sudo dnf install rtv
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Fedora Classrooms: Silverblue and Badge Design

Fedora Classroom sessions continue with two introductory sessions, on using Fedora Silverblue (February 7), and creating Fedora badges designs (February 10). The general schedule for sessions is availble on the wiki, along with resources and recordings from previous sessions. Details on both these upcoming sessions follow.

Topic: Fedora Silverblue

Fedora Silverblue is a variant of Fedora Workstation that is composed and delivered using ostree technology. It uses some of the same RPMs found in Fedora Workstation but delivers them in a way that produces an “immutable host” for the end user.  This provides atomic upgrades for end users and allows users to move to a fully containerized environment using traditional containers and flatpaks.

This session is aimed at users who want to learn more about Fedora Silverblue,
ostree, rpm-ostree, containers, and Flatpaks.  It is expected that attendees have some basic Linux knowledge.

The following topics will be covered:

  • What’s an immutable host?
  • How is Fedora Silverblue different from Fedora Workstation?
  • What is ostree and rpm-ostree?
  • Upgrading, rollbacks, and rebasing your host.
  • Package layering with rpm-ostree.
  • Using containers and container tools (podman, buildah).
  • Using Flatpaks for GUI applications

When and where

Instructor

Micah Abbott is a Principal Quality Engineer working for Red Hat. He remembers his first introduction to Linux was during university when someone showed him Red Hat Linux running on a DEC Alpha Workstation.  He’s dabbled with  various distributions in the following years, but has always had a soft spot for  Fedora. Micah has recently been contributing towards the development  of  Fedora/Red Hat CoreOS and before that Project Atomic.  He enjoys engaging with the community to help solve problems that users are facing and has most recently been spending a lot of time involved with the Fedora Silverblue community.

Topic: Creating Fedora Badges Designs

Fedora Badges is a gamification system created around the hard work of the Fedora community on the various aspects of the Fedora Project. The Badges project helps to drive and motivate Fedora contributors to participate in all different parts of Fedora development, quality, content, events, and stay active in community initiatives. This classroom will explain the process of creating a design for a Fedora Badge.

Here is the agenda for the classroom session:

  • What makes a Fedora Badge?
  • Overview of resources, website, and tickets.
  • Step by step tutorial to design a badge.

Resources needed:

  • Inkscape.
  • Comfortaa typeface.
  • Fedora badges resources (colour palettes, graphics, templates).

On Fedora, inkscape and comfortaa can be installed using dnf:

sudo dnf install inkscape aajohan-comfortaa-fonts

When and where

Instructor

Marie Nordin is a graphic designer and fine artist, with a day job as a Assistant Purchasing Manager in Rochester, NY. Marie began working on the Fedora Badges project and the Fedora Design Team in 2013 through an internship with the Outreachy program. She has maintained the design side of the Fedora Badges project for four years, as well as running workshops and teaching others how to  contribute designs to Badges.

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Chromium on Fedora finally gets VAAPI support!

Do you like playing videos in your web browser? Well, good news, the Chromium web browser available in Fedora gets a Video Acceleration API support. That makes video playback much smoother while using significantly less resources.

A little bit of history

Chromium with a VAAPI patch was already available on other distributions. But this was not the case with Fedora. I really want hardware acceleration. But my love for Fedora was holding me back. Then with sheer willpower, I joined Fedora and started maintaining a package in COPR.

I am not really a distro hopper but a DE hopper. I usually jump from Gnome to KDE and vice versa depending upon my mood. Then I started maintaining Chromium with vaapi patch on COPR. I was using the official patch which was submitted upstream for code review. I had very little hope that it will get merge. The patch is outdated and and try jobs were failing at that time.

After six months, the Chromium upstream maintainers made a statement that they are not interested to include this patch. So after that I started working on my own patch with referenced from the official patch. My patch is about using the existing flags that other operating system uses instead of creating a new flag just for experimentation.

screenshot showing chromium uses video engine

Chromium uses AMDGPU’s UVD engine while playing a video

chromium's flag screenshot

Chromium uses Existing flags on Fedora

Effects of the VAAPI patch

Chromium with this patch was extremely stable on both of my machines. They both have AMD GPU. The video playback is smooth. This improved overall power savings as well.

Comparision with/without vaapi

Credits: Tobias Wolfshappen

As you can see, chromium with the vaapi patch takes up significantly less resources in comparison to chromium without the patch and Firefox.  The CPU usage went down from 120% to 10%. The playback is smooth with no shuttering.

VA-API patch in chromium for Fedora

It was then Fedora’s Engineering Manager @ Red Hat and Chromium maintainer, Tom Callaway, finally recognises the VAAPI patch and decides to include in Fedora’s Chromium browser. Fedora becomes the second distribution to include the VAAPI patch in their official Chromium package.

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4 cool new projects to try in COPR for December 2018

COPR is a collection of personal repositories for software that isn’t carried in Fedora. Some software doesn’t conform to standards that allow easy packaging. Or it may not meet other Fedora standards, despite being free and open source. COPR can offer these projects outside the Fedora set of packages. Software in COPR isn’t supported by Fedora infrastructure or signed by the project. However, it can be a neat way to try new or experimental software.

Here’s a set of new and interesting projects in COPR.

MindForger

MindForger is a Markdown editor and a notebook. In addition to features you’d expect from a Markdown editor, MindForger lets you split a single file into multiple notes. It’s easy to organize the notes and move them around between files, as well as search through them. I’ve been using MindForger for some time for my study notes, so it’s nice that it’s available through COPR now.

Installation instructions

The repo currently provides MindForger for Fedora 29 and Rawhide. To install MindForger, use these commands:

sudo dnf copr enable deadmozay/mindforger sudo dnf install mindforger 

Clingo

Clingo is a program for solving logical problems using answer set programming (ASP) modeling language. With ASP, you can declaratively describe a problem as a logical program that Clingo then solves. As a result, Clingo produces solutions to the problem in the form of logical models, called answer sets.

Installation instructions

The repo currently provides Clingo for Fedora 28 and 29. To install Clingo, use these commands:

sudo dnf copr enable timn/clingo sudo dnf install clingo 

SGVrecord

SGVrecord is a simple tool for recording your screen. It allows you to either capture the whole screen or select just a part of it. Furthermore, it is possible to make the record with or without sound. Sgvrecord produces files in WebM format.

Installation instructions

The repo currently provides SGVrecord for Fedora 28, 29, and Rawhide. To install SGVrecord, use these commands:

sudo dnf copr enable youssefmsourani/sgvrecord sudo dnf install sgvrecord 

Watchman

Watchman is a service for monitoring and recording when changes are done to files.
You can specify directory trees for Watchman to monitor, as well as define actions
that are triggered when specified files are changed.

Installation instructions

The repo currently provides Watchman for Fedora 29 and Rawhide. To install Watchman, use these commands:

sudo dnf copr enable eklitzke/watchman sudo dnf install watchman