I need to set up my Pi3 running on Raspbian Stretch so that on boot it will enable both interfaces, routing all WAN traffic through wlan0, because on eth0 there's just an old network printer waiting for prints.
Trying this with the GUI provided by Pixel Desktop (using the underlying wicd), the Pi boots, but waits for the user to turn wifi on - then making eth0 the default gateway for all traffic and refusing to let me delete that route. I tried removing wicd completely and only using the interfaces file, but then the networking will not start, complaining about wpa_supplicant exiting with 1.
I've read up on dhcpcd5, but trying to configure that gives me only eth0 working and wlan0 being softblocked by rfkill.
So how to correctly configure my interfaces?
My current network/interfaces-file:
source-directory /etc/network/interfaces.d auto lo iface lo inet loopback allow-hotplug wlan0 wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
hostname clientid persistent option rapid_commit option domain_name_servers, domain_name, domain_search, host_name option classless_static_routes option ntp_servers option interface_mtu require dhcp_server_identifier slaac private interface eth0 static ip_address=192.168.1.1 metric 1 interface wlan0 metric 0 SSID myssid static gateway=192.168.2.1 static routers=192.168.2.1 static_domain_search=mydomain static ip_address=192.168.2.2