bug?: Changes made under etc/ are not applied with rpm-ostree update

[tepene]

I'm not sure if it's a bug, a feature, or if it's just my lack of understanding. My custom image https://github.com/tepene/ublue-bayou is based on this startingpoint. I'm getting along quite well ;) but now I'm struggling with updates.

According to https://github.com/coreos/rpm-ostree/blob/main/docs/container.md#installing-config-files

You can use any tooling you want to generate config files in /etc. When a booted system pulls an updated container images, the changes will also be applied.

But that's not what is happening. For Example: I modified the etc/yafti.yml, rebuilt the image, uploaded it to my local registry and ran rpm-ostree update on my test machine. The new update gets applied and i reboot with systemctl reboot.
After the reboot I check the content of the /etc/yafti.yml on my test machine and it still has the "old" content. Not the "new" as I would have expected.

Am I missing something crucial. Is etc/ only applied during a fresh installation and not during updates, or is there a magic command which I am missing? Any help is greatly appreciated.

[xynydev]

Answer on our Discord:

Referenced article:

https://blog.verbum.org/2014/01/24/why-ostree-requires-usretc/

---

We should probably change the default Containerfile to copy files to /usr/etc, but I'll check from the others first.

[elgabo86]

I don't know if my problem is related to this one but when I add for example virt-manager in the build script, the "libvirt" group does not merge in /usr/lib/group whereas if I install virt-manager as a layer packages, the group appears in this file.

Edit : The same goes for the qemu user.
When I install virt-manager with the build script, there is no user qemu created in /etc/passwd whereas if I install by layered packages, qemu user appears in this file.

[xynydev]

virt-manager

I think this is a different issue, I don't think this issue is affects RPMs. I've installed virt-manager in my own image and it works, no libvirt groups or qemu users, but no issues either. Is this something you except to be there ootb?

[elgabo86]

virt-manager

I think this is a different issue, I don't think this issue is affects RPMs. I've installed virt-manager in my own image and it works, no libvirt groups or qemu users, but no issues either. Is this something you except to be there ootb?

Yes virt-manager works but only with root privileges.

Normally with layered packages, just copy the line containing the "libvirt" group from /usr/lib/group to /etc/group and add the user in this group to be able to use virt-manager without root, the users "gluster " "qemu" "saslauth" are created automatically in /etc/passwd. But when the packages are installed with the script, the "libvirt" group does not exist in /usr/lib/group and the "gluster" "qemu" "saslauth" users are not created.

[tepene]

We should probably change the default Containerfile to copy files to /usr/etc, but I'll check from the others first.

Thanks! I just did some simple tests with the file /etc/justifile after I changed COPY etc /etc to COPY etc /usr/etc in my Containerfile.

Test cases

Install from scratch

After changing the Containerfile in my source, I rebased the new image on a freshly staged VM.

✔️ Files affected by COPY etc /usr/etc get copied to /etc. Everything fine.

Add some lines to /etc/justifile in my source

Then I added some lines to the /etc/justifile in my source. Rebuilt the image and updated the VM

✔️ Changes from my source got applied to file on my VM. Everything fine.

Removed some lines from /etc/justifile in my source

Then I deleted some lines to the /etc/justifile in my source. Rebuilt the image and updated the VM

✔️ Changes from my source got applied to file on my VM. Everything fine.

Add some lines to /etc/justifile on my VM and some lines to /etc/justifile in my source

Then I added some lines to /etc/justifile on my VM and I also changed some lines in /etc/justifile on my source. Rebuilt the image and updated the VM.

⚠️ This time, the file on the VM didn't get updated. Only the file under /usr/etc.

The ostree admin config-diff shows exactly that.

$ sudo ostree admin config-diff | grep justfile
M    justfile

Is there a way to resolve the config-diff?

[xynydev]

Thank's for the extensive testing @tepene !

Is there a way to resolve the config-diff?

I'd assume the command just looks at the direct difference in the files in the case auto-merging is not possible. You'd probably do a manual merge then, deciding if the updates from the image are something you want to add to your own /etc/justfile

[tepene]

one possible solution I found is rsync -avh /usr/etc/ /etc/ --delete which is noted here https://community.toradex.com/t/manually-reset-of-modified-etc-files-to-current-ostree-commit/15748/4

This might be useful if you want to "reset" your system back to the original state.

[xynydev]

#43 merged, it's done.