set_proxy.sh

#!/bin/bash
# 23-Sep-2021   James Smith     Overhauled script to function offline and based on information in the management_info plist

pb="/usr/libexec/PlistBuddy -c"
logged_in_user=$( scutil <<< "show State:/Users/ConsoleUser" | awk '/Name :/ && ! /loginwindow/ { print $3 }' )
management_plist="/Library/Management/management_info.plist"
nomad_plist="/Users/$logged_in_user/Library/Preferences/com.trusourcelabs.NoMAD.plist"
interface_name=""
search_domains=""
bypass_domains=""
country_code=""
proxy_url=""

check_network() {
    # Determine if the network is up by looking for any non-loopback (taken from /etc/rc.common)
    # internet network interfaces.

    local test
    if [ -z "${NETWORKUP:=}" ]; then
        test=$(ifconfig -a inet 2>/dev/null | sed -n -e '/127.0.0.1/d' -e '/0.0.0.0/d' -e '/inet/p' | wc -l)
        if [ "${test}" -lt 1 ]; then
            echo "Could not find a network."
            exit 0
        fi
    fi
}

get_prefs() {

    local  __variable_name="$1"
    local  __key_name="$2"
    local  __file_name="$3"

    if [ -e "$__file_name" ]; then
        __key_value=$($pb "Print $__key_name" "$__file_name" 2>/dev/null)
        exit_code=$?

        if [ $exit_code == 0 ]; then
            # shellcheck disable=SC2140
            eval "$__variable_name"="'$__key_value'"
        else
            echo "$__key_name does not exist in plist"
            exit 0
        fi
    else
        echo "Could not find management plist"
        exit 0
    fi
}

## Main Section

# Make sure the network is up
check_network

# Make sure we have the correct information for updating the proxy URL & associated domains
get_prefs bypass_domains ":network_info:bypass_domains" "$management_plist"
get_prefs search_domains ":network_info:search_domains" "$management_plist"

# Make sure we have the correct information about the user's country
get_prefs country_code ":UserAttributes:c" "$nomad_plist"

# Set proxy variable based on country data from NoMAD
case $country_code in
    AU)
        get_prefs proxy_url ":network_info:au_proxy" "$management_plist"
        ;;
    IN)
        get_prefs proxy_url ":network_info:in_proxy" "$management_plist"
        ;;
    NZ)
        get_prefs proxy_url ":network_info:nz_proxy" "$management_plist"
        ;;
    MY)
        get_prefs proxy_url ":network_info:my_proxy" "$management_plist"
        ;;
    GU)
        get_prefs proxy_url ":network_info:gu_proxy" "$management_plist"
        ;;
    *)
        get_prefs proxy_url ":network_info:au_proxy" "$management_plist"
        ;;
esac

echo "Using the following values for proxy configuration:"
echo "    Search Domains: $search_domains"
echo "    Bypass Domains: $bypass_domains"
echo "    Country Code: $country_code"
echo "    Proxy URL: $proxy_url"

networksetup -listallnetworkservices | sed '1d' | grep -Ev '^\*' |
while read -r interface_name; do
    if [[ "$interface_name" != "Bluetooth PAN" && "$interface_name" != "Thunderbolt Bridge" && "$interface_name" != "Display FireWire" && "$interface_name" != "iPhone USB" && "$interface_name" != "iPad USB" ]]; then
        echo "Configuring Interface: $interface_name"
        networksetup -setautoproxyurl "$interface_name" "$proxy_url"
        networksetup -setproxybypassdomains "$interface_name" "$bypass_domains"
        # shellcheck disable=SC2086
        # In this case we want word-splitting to occur
        networksetup -setsearchdomains "$interface_name" $search_domains
    fi
done

exit 0