Re: (Go) Library for configuring Yocto based boxes?


Nicolas Jeker
 

On Wed, 2021-08-04 at 09:13 +0000, Christofer Dutz wrote:
Hi,

it seems that on the yocto buily the vendor of my box provides
(haven't really started customizing this)
both NetworkManager as well as systemd-networkd are installed. This
seems to be bad.
In this case you should probably ask your vendor how they set up
networking and why they installed both.


I could find /etc/systemd/network, but this only contained an empty
99-default.link symlink to /dev/null
The directories /usr/lib/systemd and /run/systemd both exist, but
both don't contain any "network" directory.

Same with the /etc/NetworkManager/system-connections

Strangely I have two connections configured: "Wired connection 1" and
"Wired connection 2" which I however don't find any occurence in any
of the files on my system (Except log-files, which mention them) ...
are these configured per default? And if yes ... is systemd-networkd
or NetworkManager defining them?
It's possible that your vendor configured something different than the
defaults, hard to tell without knowing more. By default the names
"Wired connection X" are given by NetworkManager, without any user
configuration. I guess NetworkManager is currently managing your
connections.


I think I'll probably go down the route of removing NetworkManager
from the box ... having both seems to be dangerous and the systemd
appears to be more in-line with the modern way oft hings (even if it
might not be as powerful yet)
I started out with systemd-networkd and later replaced it with
NetworkManager because I wanted to use a 4G modem with ModemManager,
which wasn't well supported by systemd-networkd back then. As long as
you only use Ethernet and Wi-Fi, systemd-networkd should work fine.

Chris


-----Ursprüngliche Nachricht-----
Von: Nicolas Jeker <n.jeker@...>
Gesendet: Mittwoch, 4. August 2021 09:05
An: Christofer Dutz <christofer.dutz@...>;
yocto@...
Betreff: Re: [yocto] (Go) Library for configuring Yocto based boxes?

On Mon, 2021-08-02 at 11:32 +0000, Christofer Dutz wrote:
Hi all,

so I guess this is another case of "I should have posed my question
earlier, than I would have found the soltion myself" ;-)

So it turns out that:

                                err =
propertyConnection.Update(connectionSettings)

Only updates the settings, however it doesn't actiavate the changes
(This happens on the next boot) ... But if I also run

                                _, err =
nm.ActivateConnection(propertyConnection, device, nil)

The changes seem to be applied instantly :-)
Glad to hear it works.

So I guess I'm now safe and managed to get the things I needed
working.

I had a look and NetworkManager doesn't seem to be running, I can
find
a process systemd-networkd however, so I guess everything is setup
correctly. I also used the nmcli to experiment.

Do I understand it correctly, is systemd-networkd a different
implementation of the same service as NetworkManager? Because I can
see the configs beeing written to "/etc/NetworkManager/system-
connections"?
This doesn't sound correct. It's already some time ago that I last
worked on networking. As far as I remember, systemd-networkd and
NetworkManager are working differently:
        
Configuration files
-------------------
systemd-networkd uses *.network files in /usr/lib/systemd/network,
/run/systemd/network and /etc/systemd/network

NetworkManager uses *.nm-connection files in
/etc/NetworkManager/system-connections (and maybe others that I'm not
aware of)

Command line utility
--------------------

systemd-networkd can be controlled with networkctl NetworkManager can
be controlled with nmcli


I'm not sure why your setup even works, maybe I'm missing something.
For further reading I can recommend the ArchWiki pages (they don't
always apply perfectly to Yocto, but it's close enough and very
detailed) and the respective man pages:

https://wiki.archlinux.org/title/Systemd-networkd
https://wiki.archlinux.org/title/NetworkManager
https://man.archlinux.org/man/systemd-networkd.8
https://man.archlinux.org/man/extra/networkmanager/NetworkManager.8.en

Chris



-----Ursprüngliche Nachricht-----
Von: Nicolas Jeker <n.jeker@...>
Gesendet: Montag, 2. August 2021 13:18
An: Christofer Dutz <christofer.dutz@...>;
yocto@...
Betreff: Re: [yocto] (Go) Library for configuring Yocto based
boxes?

On Mon, 2021-08-02 at 09:35 +0000, Christofer Dutz wrote:
Hi all,

so I invested quite some time to using the NetworkManager to
configure the network settings.
I’m using a go library: github.com/Wifx/gonetworkmanager for
this.
My network configurations now end up in a directory
/etc/NetworkManager/system-connections (I can see files with the
name "{connection-id}.nmconnection"
However the changes aren't applied. If I run:

     systemctl restart systemd-networkd
systemd-networkd and NetworkManager are two different things. Make
sure that you only have one of them running at the same time.

A quick solution is to use systemd to disable the systemd-networkd
service (if that's not already the case). What I did as a more
long-
term solution is removing systemd-networkd in my distro.conf (works
in
local.conf, too):

PACKAGECONFIG_remove_pn-systemd = "networkd"

The network settings don't change (Both network devices were set
to
DHCP). (By the way … where can I see the default configuration?)
I'm currently using nmcli to set my configuration and apply it
with:

nmcli con up {connection-id}

This works for me even if the connection status is already "up".
Not
sure if it works when you replace the configuration file, but you
might give it a try. Otherwise restarting NetworkManager should
work:

systemctl restart NetworkManager

However if I reboot the box, I can see my changes applied ...
until
I run the "systemctl restart systemd-networkd" again, because
then
it switches back to the dhcp settings.
I suspect this happens because systemd-networkd "overrides" the
interface configuration that was set by NetworkManager.

Any tips on how I can apply my changes without rebooting?
 
Chris


-----Ursprüngliche Nachricht-----
Von: Nicolas Jeker <n.jeker@...>
Gesendet: Freitag, 30. Juli 2021 10:06
An: Christofer Dutz <christofer.dutz@...>;
yocto@...
Betreff: Re: [yocto] (Go) Library for configuring Yocto based
boxes?

On Fri, 2021-07-30 at 07:43 +0000, Christofer Dutz wrote:
Hi all,
 
I’m very new to the Yocto world.
 
We are currently working on migrating away from OpenWRT based
edge
devices towards ones that we now have Yocto builds for.
 
All seems to be working nicely on the yocto side.
 
Our application uses a baseline configuration in order to
connect
to our cloud service and there it fetches it’s configuration
(We’ve got a cellular fallback if connectivity doesn’t work at
all).
 
With OpenWRT there was a tool called UCI which even had a Go
wrapper which we used to apply the configuration to the box
(set
IP addresses, connect to WiFi neworks, configure the serial
ports
etc.)
 
Is there some equivalent in the Yocto world?
 
The OpenWRT wiki has a section on porting UCI to different linux
distributions [1], but you can probably skip that completely.
Searching for UCI in the recipe index [2] yields a result from
the
meta-openwrt [3] layer. I would start with adding that layer and
using the UCI recipe from there.

[1]:
https://openwrt.org/docs/techref/uci#usage_outside_of_openwrt
[2]:
https://layers.openembedded.org/layerindex/branch/master/recipes/?q=
uc
i
[3]: https://github.com/kraj/meta-openwrt

I would like to avoid generating the file content in the /etc
directory by hand and firing „restart“ commands to the
corresponding services, if there isn’t a better way.
 
Help greatly appreciated :-)
 
Chris







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