configure

#!/bin/sh -e
#
# Copyright (C) 2017 Canonical Ltd
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 3 as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# check if we have core support and exit cleanly if not
if ! systemctl --version >/dev/null 2>&1; then
    echo "Cannot run systemctl - is core-support available?"
    exit 0
fi

# list of services we can disable and enable
SERVICES="ssh rsyslog"

switch_handle_power_key() {
    dir="/etc/systemd/logind.conf.d"
    path="$dir/00-snap-core.conf"

    # Make sure the conf dir exists
    if [ ! -d $dir ]; then
        mkdir -p $dir
    fi

    case $1 in
        ignore|poweroff|reboot|halt|kexec|suspend|hibernate|hybrid-sleep|lock)
            cat <<EOF > $path
[Login]
HandlePowerKey=$1
EOF
            ;;
        *)
            echo "WARNING: invalid action '$1' supplied for system.power-key-action option"
            exit 1
            ;;
    esac

}

switch_service() {
	case "$1" in
		false)
			# When the unit is already enabled but not active a call with
			# --now does start the unit so we have to check for that  case
		        # and explicitly start the unit.
                        if systemctl status "$2.service"|grep -q "Loaded: masked"; then
                                systemctl unmask "$2.service"
                        fi
			if [ "$(systemctl is-enabled "$2.service")" = "disabled" ]; then
				systemctl enable "$2.service"
			fi
			if [ "$(systemctl is-active "$2.service")" = "inactive" ]; then
				systemctl start "$2.service"
			fi
			;;
		true)
			# A simple `systemctl disable --now ssh.service` doesn't work
			# and fails with an error message. Because of that we're going
			# in two steps here and disable first and then stopping the
			# service unit.
			systemctl disable "$2.service"
                        # we need to mask the unit so that there is a symlink
                        # with the service name in /etc/systemd/system. If
                        # there is nothing the "writable-path" magic will
                        # copy the "$2.service" symlink on boot because the
                        # directory /etc/systemd/system is "synced"
			systemctl mask "$2.service"
			systemctl stop "$2.service"
			;;
		*)
			echo "ERROR: Invalid value '$1' provided for option service.$2.disable"
			exit 1
	esac
}

update_pi_config_value() {
    path="$1"
    key="$2"
    value="$3"

    if [ -z "$value" ]; then
        # empty - unset an option
        if grep -q "^[ \t]*${key}=" "$path"; then
            sed "/^[ \t#]*${key}=/ s/^#*/#/" "$path" > "${path}.tmp"
            mv "${path}.tmp" "$path"
        fi
    else
        if ! grep -q "^[ \t]*${key}=${value}$" "$path"; then
            # non-empty - set an option
            export key value
            gawk --sandbox -v pat="^[ \t#]*$key=.*" -f - "$path" >"${path}.tmp" <<'EOF'
$0 ~ pat {
     gsub(pat, sprintf("%s=%s",ENVIRON["key"],ENVIRON["value"]))
     ok=1
}
{
    print
}
END {
    if (!ok)
        printf("%s=%s\n",ENVIRON["key"],ENVIRON["value"])
}
EOF
            mv "${path}.tmp" "$path"
        fi
    fi
}

for service in $SERVICES; do
    value=$(snapctl get service."$service".disable)
    if [ -n "$value" ]; then
        switch_service "$value" "$service"
    fi
done

powerkey=$(snapctl get system.power-key-action)
if [ -n "$powerkey" ]; then
    switch_handle_power_key "$powerkey"
fi

PI_CONFIG_KEYS="disable_overscan framebuffer_width framebuffer_height
 framebuffer_depth framebuffer_ignore_alpha overscan_left overscan_right
 overscan_top overscan_bottom overscan_scale display_rotate hdmi_group
 hdmi_mode hdmi_drive avoid_warnings gpu_mem_256 gpu_mem_512 gpu_mem
 sdtv_aspect config_hdmi_boost hdmi_force_hotplug"
PI_CONFIG="${TEST_UBOOT_CONFIG:-/boot/uboot/config.txt}"
if [ -f "$PI_CONFIG" ]; then
    for key in $PI_CONFIG_KEYS; do
        value=$(snapctl get "pi-config.$(echo "$key"|tr _ -)")
        update_pi_config_value "$PI_CONFIG" "$key" "$value"
    done
fi