Connecting to WiFi using adb shell

You can add a network entry into the wpa_supplicant.conf yourself (or within your script) Essentially connect manually once, then do:

adb pull /data/misc/wifi/wpa_supplicant.conf

and integrate the network entry into your script for automation. Example simple script:

#!/bin/bash
#

# Get this information by connecting manually once, and do
#   adb pull /data/misc/wifi/wpa_supplicant.conf
ADB_PULL="adb pull /data/misc/wifi/wpa_supplicant.conf"
WIRELESS_CTRL_INTERFACE=wlan0
WIRELESS_SSID=Gondolin
WIRELESS_KEY_MGMT="WPA-EAP IEEE8021X"
WIRELESS_EAP=PEAP
WIRELESS_USER=Turgon
WIRELESS_PASSWORD=IdrilCelebrindal

adb start-server
adb wait-for-device
echo "adb connection....[CONNECTED]"
adb root
adb wait-for-device
adb remount
adb wait-for-device

pushd /tmp
rm wpa_supplicant.conf 2>/dev/null # Remove any old one
adbpull_status=`$ADB_PULL 2>&1`
echo -e "\nAttempting: $ADB_PULL"
if [ `echo $adbpull_status | grep -wc "does not exist"` -gt 0 ]; then
    echo "  wpa_supplicant.conf does not exist yet on your device yet."
    echo "This means you have not used your wireless yet."
    echo ""
    echo "Taking our best shot at creating this file with default config.."

    echo "ctrl_interface=$WIRELESS_CTRL_INTERFACE" >> wpa_supplicant.conf
    echo "update_config=1" >> wpa_supplicant.conf
    echo "device_type=0-00000000-0" >> wpa_supplicant.conf
else
    echo $adbpull_status
    echo "  wpa_supplicant.conf exists!"
fi

echo ""
echo "Add network entry for wpa_supplicant.conf.."
echo "" >> wpa_supplicant.conf
echo "network={" >> wpa_supplicant.conf
echo "  ssid=\"$WIRELESS_SSID\"" >> wpa_supplicant.conf
echo "  key_mgmt=$WIRELESS_KEY_MGMT" >> wpa_supplicant.conf
echo "  eap=$WIRELESS_EAP" >> wpa_supplicant.conf
echo "  identity=\"$WIRELESS_USER\"" >> wpa_supplicant.conf
echo "  password=\"$WIRELESS_PASSWORD\"" >> wpa_supplicant.conf
echo "  priority=1" >> wpa_supplicant.conf
echo "}" >> wpa_supplicant.conf
echo "Pushing wpa_supplicant.conf.."
adb push wpa_supplicant.conf /data/misc/wifi/wpa_supplicant.conf
popd #/tmp

adb shell chown system.wifi /data/misc/wifi/wpa_supplicant.conf
adb shell chmod 660 /data/misc/wifi/wpa_supplicant.conf

echo ""
echo "Finished!"
adb shell am start -a android.intent.action.MAIN -n com.android.settings/.Settings
echo "Please toggle wifi off/on now.. (ifconfig not sufficient, monkey this)"

Late to the party, but I came up with a way to accomplish this on a device without root.

It may not be pretty, but it works.

Basically what I propose is to create an app that joins an access point based on EXTRAS given when starting the app. The EXTRAS are then provided using the am command's -e <KEY> <VALUE> parameter.

I already build an app which does so and it's available here: https://github.com/steinwurf/adb-join-wifi

Once the app is installed, a wifi access point can be joined using the following ADB command:

adb shell am start -n com.steinwurf.adbjoinwifi/com.steinwurf.adbjoinwifi.MainActivity -e ssid [SSID] -e password_type [PASSWORD_TYPE] -e password [WIFI PASSWORD]

There's more info in the README on Github.

Hope it helps someone.