Hello.
My code.

package main

import (
	"fmt"
	"time"

	wifi "github.com/mark2b/wpa-connect"
)

func main() {
	ssid := "My_name_wifi"
	password := "My_password_wifi"
	if conn, err := wifi.ConnectManager.Connect(ssid, password, time.Second*60); err == nil {
		fmt.Println("Connected", conn.NetInterface, conn.SSID, conn.IP4.String(), conn.IP6.String())
		// fmt.Println("Connected", conn)
	} else {
		fmt.Println("Err connect: ", err)
	}
}

An error appears - "address_not_allocated".
Wifi is working properly. The password is correct.
Can you tell me what the problem may be?

I understand that the problem is related to the code -

func (self *connectContext) hasIP() bool {
	return self.ip4 != nil && self.ip6 != nil
}

Trying to figure out how to use this, it seems like a good way to go with headless config on a raspberry pi. I'm calling it like this:

bssList, err := wifi.ScanManager.Scan()
	if err != nil {
		return err
	}
	for _, bss := range bssList {
		print(bss.SSID, bss.Signal, bss.KeyMgmt)
	}

	conn, err := wifi.ConnectManager.Connect(wificreds.SSID, wificreds.Password, time.Second*60)
	if err != nil {
		return err
	}

But all I'm getting is:
wpa_supplicant knows nothing about this interface.

When I ps wpa_supplicant the table looks like this:

root       377     1  0 04:24 ?        00:00:00 /sbin/wpa_supplicant -u -s -O /run/wpa_supplicant
root       421     1  0 04:24 ?        00:00:00 wpa_supplicant -B -c/etc/wpa_supplicant/wpa_supplicant.conf -iwlan0 -Dnl80211,wext

I see the -u option in there and when I run dbus-send --system --dest=org.freedesktop.DBus --type=method_call --print-reply /org/freedesktop/DBus org.freedesktop.DBus.ListNames I get:

method return time=1609130134.013166 sender=org.freedesktop.DBus -> destination=:1.16 serial=3 reply_serial=2
   array [
      string "org.freedesktop.DBus"
      string "org.freedesktop.login1"
      string "org.freedesktop.timesync1"
      string "org.freedesktop.systemd1"
      string "org.freedesktop.Avahi"
      string "org.bluez"
      string ":1.12"
      string ":1.0"
      string ":1.1"
      string ":1.2"
      string ":1.16"
      string ":1.3"
      string ":1.4"
      string "fi.epitest.hostap.WPASupplicant"
      string "fi.w1.wpa_supplicant1"
    

Running the latest RaspberryPi OS armhf as well.

@mark2b Opening this up as an issue more for documentation purposes in case anyone else runs into this. I ran into this issue while developing a Go service using your library on Ubuntu. Likely not an issue on Raspberry PI OS since it doesn't use Polkit.

When using DBUS to manage wpa_supplicant some Linux distributions utilize Polkit (formerly known as PolicyKit) to manage permissions for processes that can interface directly with the bus.

This blog provides a good treatise on the subject matter. Developers running on Debian based distro's like Ubuntu will need to modify the /etc/dbus-1/system.d/wpa_supplicant.conf to allow your user (non-root) access to interface with dbus.

Add another <policy_user> block in addition to the existing one.

<busconfig>
        <policy user="yourUserName">
                <allow own="fi.w1.wpa_supplicant1"/>

                <allow send_destination="fi.w1.wpa_supplicant1"/>
                <allow send_interface="fi.w1.wpa_supplicant1"/>
                <allow receive_sender="fi.w1.wpa_supplicant1" receive_type="signal"/>
        </policy>
</busconfig>

Note the policy user you set should be identical to the owner of the process running the Go binary using the wpa-connect library.

The scan & connect managers both hardcode the wifi dev name to wlan0 unless the developer overrides the device name prior to calling the Scan() or Connect() methods.

Following your code example one would need to do the following:

wifi.ScanManager.NetInterface  = "customUDev0"
if bssList, err := wifi.ScanManager.Scan(); err == nil {
	for _, bss := range bssList {
		print(bss.SSID, bss.Signal, bss.KeyMgmt)
	}
}

Is there any reason why the Scan/Connect manager define global vars with a pre-instantiated struct setting the wifi uDev name? I think it would make more sense to require the developer to create a reference to their own Scan/Connect managers. Consider a case where the system using this library has multiple wifi devices.