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Highlights of YaST Development Sprint 85

September 26th, 2019 by

Refactored Network on its way to Tumbleweed

A few weeks ago we submitted the first round of changes to the network module to Tumbleweed. At that point, it was still using the old data model for most operations (except routing and DNS handling) and a lot of work remained to be done.

We have been working hard on improving the overall quality of this module and we will submit an updated (and much improved) version in the upcoming days. To summarize, here are some highlights:

  • Completed the new data model (support for TUN/TAP, bridges, bonding, VLANs, etc.).
  • New wireless configuration workflow.
  • Revamped support for interface renaming and driver assignment, including better udev rule handling.
  • Fixed /etc/hosts handling when switching from static to DHCP based configuration.
  • Many small fixes in several areas.

Are we done with the refactoring? No, we are still working on improving S390 support and fixing small issues, but most of the work is already done.

Of course, as soon as we finish, we will publish a blog entry with the gory details. But, as we know that you love screenshots, let us show you a handful of them.

Although we have not introduced big user interface changes, we have tried to improve small things, like properly displaying whether an interface belongs to a VLAN or hiding the "Hardware" tab for virtual interfaces.

DNS resolution not working during installation, or: openQA is different

When we got a bug report that DNS resolution was not working during installation (since SLE-15 apparently), a solution seemed straightforward: /run/netconfig/resolv.conf was missing because the /run directory was not mirrored (bind-mounted) into the target system. That’s a task that used to be done by yast-storage in times before SLE-15 and was for some unknown reason forgotten when we implemented yast-storage-ng. A one-line fix was easily done, tested, and submitted.

Or so it seemed.

A few days later we got reports from SLE openQA that tests started to fail with this patch. Nothing networking related but the installation did not finish because the 10 seconds countdown dialog (‘going to reboot’) at the very end of the installation was frozen. The UI didn’t accept any input whatsoever. But whatever we tried, the issue was not reproducible outside openQA. YaST logs from openQA showed that /run got mounted as planned and was cleanly unmounted at the end of the installation – before that frozen dialog. So no clue so far and the issue was set aside for a while. Until the same reports came in from Tumbleweed testing. It was clearly linked to this one-line patch. But how?

It stayed a mystery until a chat with an openQA expert shed some light on the issue. What we thought was happening was: openQA stopped the dialog (by pressing a button) and when it tried to go on the OK button did not respond anymore. What we learned does actually happen is this: openQA stops the dialog, then switches from X to the text console, collects logs, switches back to X, and then the UI does not respond anymore. So that was quite an essential point missing.

And with this it was easily reproduced outside openQA: the X logs showed that the X server lost all its input devices after the switch. And that was because someone had deleted the whole /run directory. The YaST logs didn’t contain a hint (of course not, would have been too easy) but grepping the sources found the place where YaST deleted the directory.

The code had been added after complaints that the installation left a cluttered /run directory – of course the installation did leave files there, since it was forgotten to bind-mount the directory. So once the mentioned patch bind-mounted it again the deletion code cleaned up not /run in the installation target system but the real /run as well – cutting off the X server from the outside world resulting in freezing the openQA test.

And the moral of the story is: probably none. But it highlights again that the automated test setup can have unexpected feedback on the test itself. Luckily in this case, as the issue would not have been noticed otherwise.

Computer, Enlarge the Device Graph

The partitioner module has a graphical view to help you see the relations in more complex storage setups:

If you turn the mouse scroll wheel up or down, we will zoom the view in or out. Now the direction matches the behavior in web browsers and online maps, previously we had it the wrong way around.

Update: during proofreading, a team mate told me: "A device graph? That’s not a device graph. THAT’s a device graph:"

Highlights of YaST Development Sprint 84

September 16th, 2019 by

The YaST Team finished yet another development sprint last week and we want to take the opportunity to let you all glance over the engine room to see what’s going on.

Today we will confess an uncomfortable truth about how we manage the Qt user interface, will show you how we organize our work (or at least, how we try to keep the administrative part of that under control) and will give you a sneak peak on some upcoming YaST features and improvements.

Let’s go for it!

There Be Dragons: YaST Qt UI Event Handling

The YaST Qt UI is different in the way that it uses Qt. Normal Qt applications are centered around a short main program that after initializing widgets passes control to the Qt event loop. Not so YaST: it is primarily an interpreter for the scripts (today in Ruby, in former times in YCP) that are executed for the business logic. Those scripts, among other things, also create and destroy widget trees. But the control flow is in the script, not in a Qt event loop. So YaST uses different execution threads to handle both sides: graphic’s system events for Qt widgets and the control flow from the scripts.

This was always quite nonstandard, and we always needed to do weird things to make it happen. We always kind of misused Qt to hammer it into shape for that. And we always feared that it might break with the next Qt release, and that we might have a hard time to make it work again.

This time has now come with bug#1139967, but we were lucky enough to find a Qt call to bring it back to life; a QEventLoop::wakeUp() call fixed it. We don’t quite know (yet) why, though. Any hint, anyone?.

Should we even tell you that? Well, we think you deserve to know. After all, it worked well for about 20 years (!)… and now it’s working again.

The Refactoring of YaST Network Keeps Going

What is still not working that fine is the revamped network management. We have been working on it during the latest sprint, but it will take at least another one before it’s stable enough to be submitted to openSUSE Tumbleweed.

On which parts have we be working during the this sprint? Glad you asked! 😉 We are cleaning the current mess in wireless configuration. Soon that part will be more intuitive and consistent with other types of network. We are also making sure we propose meaningful defaults for the new cards added to the network configuration (all types of cards, not only wireless). The functionality to configure udev in order to enjoy stable names for the network interfaces has also received some love. The new version is more stable and flexible. And last but not least, we are improving the device activation in s390 systems for it to be more straightforward in the code and more clear in the user interface.

If everything goes as planned, by the end of the next sprint we will be ready to submit the improved YaST Network to Tumbleweed. That will be the right time for a dedicated blog post with screenshots and further explanations of all the changes.

Enhancing the Partitioner Experience with Encrypted Devices

And talking about ongoing work, we are currently working to broaden the set of technologies and use-cases the Partitioner supports when it comes to data encryption. As with the network area, the big headlines in that regard will have to wait for future blog posts. But if you look close enough to the user interface of the Partitioner available in Tumbleweed you can start spotting some small changes that anticipate the upcoming new features.

The first change is very subtle. When visualizing the details of an encrypted device, next to the previously existing “Encrypted: Yes” text you will now be able to see the concrete type of encryption. For all devices encrypted using YaST, that type will always be LUKS1 since that’s the only format that YaST has supported… so far. 😉

Partitioner: show the type of encryption

Some other small changes are visible when editing an encrypted device. If such a device was not originally encrypted in the system, nothing changes apart from minor adjustments in the labels. The user simply sees a form with an empty field to enter the password.

Encrypting a plain device

When editing for a second time a device that was already marked for encryption during the current execution of the Partitioner, the form is already prefilled with the password entered before. In the past, the previous encryption layer was ditched (so it’s password and other arguments were forgotten) and the user had to define the encryption again from scratch. That will become even more relevant soon, when the form for encryption becomes more than just a password field. Stay tuned for news in that regard.

Editing an encrypted device

Moreover, when editing a device that is already encrypted in the system, an option is offered to just use the existing encryption layer instead of replacing it with a (likely more limited) encryption created by the Partitioner.

Keeping the previous encryption layer

Apart from opening the door for more powerful and relevant changes in the area of encryption, these changes represent an important usability improvement by themselves.

Tidying up the YaST Team’s Trello Board

As you can see in this report and in all the previous ones, the YaST Team works constantly on many different areas like installation, network management, storage technologies… you name it. We use Trello to organize all that work. For each bug in Bugzilla or feature in Jira there is a corresponding Trello card. As it happens, sometimes when a bug is closed its Trello card is forgotten to be updated.

A check with ytrello revealed that, out of a total of 900-something cards, about 500 were outdated and could be closed. More than the half! Why so many?

We found that quite a number of these cards were open cards in closed (archived) lists. So when you archive a list, don’t forget to archive its cards before. We have just learned that Trello does not do this automatically. That’s exactly why there’s a menu item Archive All Cards in This List... besides Archive This List in the Trello user interface.

Back to work!

This has been a summer of promises on our side. We told you we are working to improve our user interface library (libYUI), revamping the code to manage the network configuration, extending the support for encryption… which means we have a lot work to be finished.

So let us go back to work while you do your part – having a lot of fun!

openSUSE OBS git mirror

September 13th, 2019 by

There was some discussion about our OBS and how in contrast Gentoo, VoidLinux or Fedora used git to track packages.

So I made an experimental openSUSE:Factory git mirror to see how well it goes and how using it feels.
The repo currently needs around 1GB but will slowly grow over time. I did not want to spend effort to import all history.

Binary files are replaced by cryptographically secure symlinks into IPFS
and I am currently providing files up to 9MB there.

If you can not run ipfs, you can still get these files through any of the public gateways like this:
curl https://ipfs.io$(readlink packages/a/aubio/aubio-0.4.9.tar.bz2) > OUTPUT

So some benefits are already obvious.
It is now much easier to find and download our patches.
Downloading and seaching all of openSUSE is now much faster.
And it works even on Thursdays (when our maintenance window often causes OBS downtimes).

It is meant to be a read-only mirror, so there is no point in opening pull-requests on github.

I hope, you enjoy it and have a lot of fun…