Using "env" in subprocess.run clears all environment variables

[jwmullally]

Hello,

SystemCommand.nmcli() uses the env parameter of subprocess.run to set the LANG environment variable. Unfortunately this clobbers the rest of the environment and can cause issues when configuring nmcli through environment variables.

---

E.g. On BalenaOS, the host DBUS socket is accessed by specifying an alternative DBUS_SYSTEM_BUS_ADDRESS.

export DBUS_SYSTEM_BUS_ADDRESS="unix:path=/host/run/dbus/system_bus_socket"
nmcli dev show

However as this environment variable is overwritten by usage of a minimal env paramater, running any nmcli command produces the following exception, as the command can't reach the default DBUS endpoint.

import nmcli
nmcli.disable_use_sudo()
nmcli.device.show_all()

UnspecifiedException: Unknown or unspecified error [code:1, detail:Error: Could not create NMClient object: Could not connect: No such file or directory.

[jwmullally]

Here is a workaround that works for me:

def wrap_fn_remove_kwarg(fn):
    # Workaround environment clear issue
    # https://github.com/ushiboy/nmcli/issues/59
    def call_fn_remove_kwarg(*args, **kwargs):
        kwargs.pop('env', None)
        return fn(*args, **kwargs)
    return call_fn_remove_kwarg


import nmcli
nmcli.disable_use_sudo()
nmcli._syscmd._run = wrap_fn_remove_kwarg(nmcli._syscmd._run)
nmcli.device.show_all()

[ushiboy]

Thanks for the report.

I understand the situation. I'll try to modify the existing environment variables so that they can be used as well.

[ushiboy]

@jwmullally
Version 1.1.2 has been released, try it out.