Issue with handling array of dictionary (NetworkManager.Settings)

[logicog]

The following code

#!/usr/bin/env ruby

require "dbus"

bus = DBus::SystemBus.instance

@nm_service = bus.service("org.freedesktop.NetworkManager")
@nm_settings = @nm_service.object("/org/freedesktop/NetworkManager/Settings")
@nm_settings_iface = DBus::ProxyObjectInterface.new(@nm_settings, "org.freedesktop.NetworkManager.Settings")
@nm_settings_iface.define_method("AddConnection", "in connection:a{sa{sv}}, out path:o");
new_c = { "connection" => {"id" => "LAN", "type"=>"802-3-ethernet"},
          "ipv4" => {"method"=>"manual", "address-data" => [{"address" => "192.168.2.1", "prefix" => 24}]  } }

p "Creating new LAN connection"
p new_c
clan_path = @nm_settings_iface.AddConnection(new_c)

gives the following error:

$ ./new_con.rb 
"Creating new LAN connection"
{"connection"=>{"id"=>"LAN", "type"=>"802-3-ethernet"}, "ipv4"=>{"method"=>"manual", "address-data"=>[{"address"=>"192.168.2.1", "prefix"=>24}]}}
/var/lib/gems/3.1.0/gems/ruby-dbus-0.23.1/lib/dbus/connection.rb:95:in `block in send_sync_or_async': ipv4.address-data: can't set property of type 'aa{sv}' from value of type 'av'; caused by 3 sender=:1.10 -> dest=:1.8432 serial=495323 reply_serial=3 path=; interface=; member= error_name=org.freedesktop.NetworkManager.Settings.Connection.InvalidProperty (DBus::Error)
        from /var/lib/gems/3.1.0/gems/ruby-dbus-0.23.1/lib/dbus/connection.rb:284:in `process'
        from /var/lib/gems/3.1.0/gems/ruby-dbus-0.23.1/lib/dbus/connection.rb:228:in `send_sync'
        from /var/lib/gems/3.1.0/gems/ruby-dbus-0.23.1/lib/dbus/connection.rb:94:in `send_sync_or_async'
        from /var/lib/gems/3.1.0/gems/ruby-dbus-0.23.1/lib/dbus/proxy_object_interface.rb:70:in `block (2 levels) in define_method_from_descriptor'
        from ./new_con.rb:16:in `<main>'
/var/lib/gems/3.1.0/gems/ruby-dbus-0.23.1/lib/dbus/connection.rb:95:in `block in send_sync_or_async': ipv4.address-data: can't set property of type 'aa{sv}' from value of type 'av' (DBus::Error)
        from /var/lib/gems/3.1.0/gems/ruby-dbus-0.23.1/lib/dbus/connection.rb:284:in `process'
        from /var/lib/gems/3.1.0/gems/ruby-dbus-0.23.1/lib/dbus/connection.rb:228:in `send_sync'
        from /var/lib/gems/3.1.0/gems/ruby-dbus-0.23.1/lib/dbus/connection.rb:94:in `send_sync_or_async'
        from /var/lib/gems/3.1.0/gems/ruby-dbus-0.23.1/lib/dbus/proxy_object_interface.rb:70:in `block (2 levels) in define_method_from_descriptor'
        from ./new_con.rb:16:in `<main>'

The expected behaviour is that the address-data array: [{"address" => "192.168.2.1", "prefix" => 24}] is indeed sent via DBus as 'aa{sv}' and not as 'av'

[mvidner]

Thanks for the report!

The problem is that ruby-dbus has no way of knowing what type the NetworkManager API is actually expecting.
This is a known problem, please see #124 for a slightly more general description, also using the org.freedesktop.NetworkManager.Settings interface

You need to explicitly set the data type, like this:

new_c = {
  "connection" => {
    "id" => "LAN",
    "type" => "802-3-ethernet"
  },
  "ipv4" => {
    "method" => "manual",
    "address-data" => DBus::Data.make_typed("aa{sv}", [{ "address" => "192.168.2.1", "prefix" => 24 }])
  }
}

which then gives me another error:

ipv4.addresses: this property cannot be empty for 'method=manual'; ... error_name=org.freedesktop.NetworkManager.Settings.Connection.MissingProperty

but that is left for you to solve, consulting the NM API documentation

[logicog]

Thanks so much for the quick help! I will dig into this further!

[mvidner]

@logicog feel free to reopen this if you have related questions or problems