Re: How to create a VPN connection by network manager DBUS?

[Dan Williams <dcbw redhat com>]

On Fri, 2014-05-23 at 22:29 +0800, Lei Xue wrote:
> Hi All,
>
> I have an OpenVPN configuration file, and I can import it via Network
> Manager GUI to create a VPN connection.
>
> Now, I would like to write a script to create the VPN connection based on
> configuration file. I found that I can use Network Manager DBUS to do that,
> but I just got the examples on how to activate the exist connection. I
> found them from this thread:
> https://mail.gnome.org/archives/networkmanager-list/2009-February/msg00075.html
> .
>
> And there is not enough information on how to do the VPN type connection,
> it will be very appreciated if you can provide any tips or suggestion.
>
> I would like to use Perl script to do that, but any other language will be
> all right to learn about.

THere are some examples about adding a non-VPN connection here:

http://cgit.freedesktop.org/NetworkManager/NetworkManager/tree/examples/python/dbus
http://cgit.freedesktop.org/NetworkManager/NetworkManager/tree/examples/python/gi/add_connection.py
http://cgit.freedesktop.org/NetworkManager/NetworkManager/tree/examples/ruby/add-connection.rb

which should give you an idea of how to do it in some different
languages dynamically.

What's obviously different are the specific key/value pairs that you
need to send, and those are dependent on each VPN plugin.  There isn't
formal documentation on those, but it's centrally located in the code:

https://git.gnome.org/browse/network-manager-openvpn/tree/src/nm-openvpn-service.c#n99

If you'd like to see what the NM-openvpn import/export code looks like
that's at:

https://git.gnome.org/browse/network-manager-openvpn/tree/properties/import-export.c

but in general, the conversion is pretty straight-forward and the key
names are the same as the openvpn config equivalents.

There's another option: just create the NM config file and drop that
into /etc/NetworkManager/system-connections, and since you'll be giving
it a known UUID, you can then call Settings.GetConnectionByUuid() via
D-Bus and then use the returned object path to start the VPN connection.
You can see the config file NM writes by going through the import
process in nm-connection-editor and the saving the resulting connection,
and it'll show up in /etc/NetworkManager/system-connections.

Hopefully that's enough to get you started, let us know if you have any
more questions!

Dan