Blink Raspberry Pi LEDs depending on network status

rpi-netstatus.service

[Unit]
Description=Network status as LED
StartLimitIntervalSec=0

[Service]
Type=simple
Restart=always
RestartSec=1
User=pi
ExecStart=/usr/local/bin/rpi-netstatus.sh

[Install]
WantedBy=multi-user.target

rpi-netstatus.sh

#!/bin/bash

GPIO_WORKING=26
GPIO_ERROR=19
GPIO_WARNING=13
GPIO_SUCCESS=6
GPIO_CONNECTION=16
TEST_IP_HOST=8.8.8.8
TEST_DNS_HOST=google.com
TEST_HTTP_URL="https://www.google.com"
TEST_WLAN_IF=wlan0
TEST_INTERVAL=10s


function usage() {
    echo "$0 [options]"
    echo ""
    echo "  --ip            TEST_IP_HOST    [default $TEST_IP_HOST]"
    echo "    IP to ping to test connectivity."
    echo ""
    echo "  --dns           TEST_DNS_HOST   [default $TEST_DNS_HOST]"
    echo "    Domain name to ping to test connectivity and DNS lookup."
    echo ""
    echo "  --url           TEST_HTTP_URL   [default $TEST_HTTP_URL]"
    echo "    URL to test for HTTP(S) connectivity."
    echo ""
    echo "  --interface     TEST_WLAN_IF    [default $TEST_WLAN_IF]"
    echo "    Interface to check whether is up and has a valid IPv4."
    echo ""
    echo ""
    echo "  --interval      TEST_INTERVAL   [default $TEST_INTERVAL]"
    echo "    Interval in seconds between consecutive tests."
    echo ""
    echo "  --success       GPIO_SUCCESS    [default $GPIO_SUCCESS]"
    echo "    GPIO pin number for the LED identifying success for ping and http."
    echo ""
    echo "  --warning       GPIO_WARNING    [default $GPIO_WARNING]"
    echo "    GPIO pin number for the LED identifying partial success for ping and http."
    echo ""
    echo "  --error         GPIO_ERROR      [default $GPIO_ERROR]"
    echo "    GPIO pin number for the LED identifying failure for ping and http."
    echo ""
    echo "  --connection    GPIO_CONNECTION [default $GPIO_CONNECTION]"
    echo "    GPIO pin number for the LED marking whether the network interface is up and running."
    echo ""
    echo "  --working       GPIO_WORKING    [default $GPIO_WORKING]"
    echo "    GPIO pin number for the LED marking that tests are being performed."
    echo ""
    echo "  -h, --help"
    echo "    Shows this help."
}


while [[ $# -gt 0 ]]; do
    case "$1" in
        --ip)           shift; TEST_IP_HOST="$1";;
        --dns)          shift; TEST_DNS_HOST="$1";;
        --url)          shift; TEST_HTTP_URL="$1";;
        --interface)    shift; TEST_WLAN_IF="$1";;
        --interval)     shift; TEST_INTERVAL="$1";;
        --success)      shift; GPIO_SUCCESS="$1";;
        --warning)      shift; GPIO_WARNING="$1";;
        --error)        shift; GPIO_ERROR="$1";;
        --connection)   shift; GPIO_CONNECTION="$1";;
        --working)      shift; GPIO_WORKING="$1";;
        -h|--help)
            usage
            exit 0
            ;;
        *)
            echo "Unrecognized option: $1"
            usage
            exit 1
            ;;
    esac
    shift
done


ALL_PINS=("$GPIO_WORKING" "$GPIO_ERROR" "$GPIO_WARNING" "$GPIO_SUCCESS" "$GPIO_CONNECTION")

function _boolecho() {
    case $1 in
        1) echo -n "OK";;
        0) echo -n "FAIL";;
        *) echo -n "N/A";;
    esac
}

function _set_pins() {
    VALUE="$1"
    shift
    for PIN in "${@}"; do
        DEST="/sys/class/gpio/gpio${PIN}/value"
        if [[ -f "$DEST" ]]; then
            echo "$VALUE" > "$DEST"
        fi
    done
}

function seth() {
    _set_pins 1 "$@"
}

function setl() {
    _set_pins 0 "$@"
}

function blink() {
    PIN="$1"
    TIMES="$2"
    PERIOD="$3"
    if [[ -z "$PERIOD" ]]; then
        PERIOD="0.3s"
    fi
    while [[ $TIMES -ne 0 ]]; do
        seth "$PIN"
        sleep "$PERIOD"
        setl "$PIN"
        if [[ $TIMES -gt 0 ]]; then
            TIMES=$(( TIMES - 1 ))
        fi
    done
}

function setup_pins() {
    for PIN in "${ALL_PINS[@]}"; do
        echo "Exporting pin $PIN..."
        echo "$PIN" > /sys/class/gpio/export
        sleep 1s
        DEST="/sys/class/gpio/gpio${PIN}/direction"
        if [[ -f "$DEST" ]]; then
            echo out > "/sys/class/gpio/gpio${PIN}/direction"
        fi
        setl "$PIN"
    done
}

function teardown_pins() {
    for PIN in "${ALL_PINS[@]}"; do
        echo "Unexporting pin $PIN..."
        setl "$PIN"
        echo "$PIN" > /sys/class/gpio/unexport
    done
}

function greet() {
    for PIN in "${ALL_PINS[@]}"; do
        blink "$PIN" 1
    done
}

function goodbye() {
    for PIN in "${ALL_PINS[@]}"; do
        seth "$PIN"
    done
    sleep 0.5s
    for PIN in "${ALL_PINS[@]}"; do
        setl "$PIN"
    done
}

function do_ping() {
    IP_OK=2
    DNS_OK=2
    HTTP_OK=2

    if [[ $# -eq 0 ]] || [[ $1 -eq 0 ]]; then
        seth "$GPIO_WORKING"
        if ping -c 1 -W 1 "$TEST_IP_HOST" > /dev/null 2>&1; then
            IP_OK=1

            if ping -c 1 -W 1 "$TEST_DNS_HOST" > /dev/null 2>&1; then
                DNS_OK=1

                case "$(curl -s --max-time 2 -I "$TEST_HTTP_URL" | sed 's/^[^ ]*  *\([0-9]\).*/\1/; 1q')" in
                  [23]) HTTP_OK=1;;
                  *   ) HTTP_OK=0;;
                esac
            else
                DNS_OK=0
            fi
        else
            IP_OK=0
        fi
        setl "$GPIO_WORKING"
    fi

    echo "Ping on IP: $(_boolecho $IP_OK); Ping on DNS: $(_boolecho $DNS_OK); Curl on DNS: $(_boolecho $HTTP_OK)"
    if [[ $IP_OK -eq 1 ]] && [[ $DNS_OK -eq 1 ]] && [[ $HTTP_OK -eq 1 ]]; then
        seth "$GPIO_SUCCESS"
        setl "$GPIO_WARNING"
        setl "$GPIO_ERROR"
    elif [[ $IP_OK -eq 1 ]] || [[ $DNS_OK -eq 1 ]] || [[ $HTTP_OK -eq 1 ]]; then
        setl "$GPIO_SUCCESS"
        seth "$GPIO_WARNING"
        setl "$GPIO_ERROR"
    else
        setl "$GPIO_SUCCESS"
        setl "$GPIO_WARNING"
        seth "$GPIO_ERROR"
    fi
}


BLINK_JOB=""

function _blinkjob_kill() {
    if [[ -n "$BLINK_JOB" ]]; then
        kill "$BLINK_JOB"
        BLINK_JOB=""
    fi
}

function _blinkjob_start() {
    if [[ -z "$BLINK_JOB" ]]; then
        blink "$1" -1 &
        BLINK_JOB=$!
    fi
}

function do_wifi() {
    IF_STATUS="$(ip addr show "$TEST_WLAN_IF" 2> /dev/null)"
    UP=2
    HAS_IP=2
    if echo "$IF_STATUS" | grep -F "state UP" > /dev/null 2>&1; then
        UP=1
        if echo "$IF_STATUS" | grep '\binet \([0-9]\+\.\)\{3\}[0-9]\+/[0-9]\+\b' > /dev/null 2>&1; then
            HAS_IP=1
        else
            HAS_IP=0
        fi
    else
        UP=0
    fi
    echo "IF is up: $(_boolecho $UP); IF has IP: $(_boolecho $HAS_IP)"
    if [[ $UP -eq 1 ]] && [[ $HAS_IP -eq 1 ]]; then
        _blinkjob_kill
        seth "$GPIO_CONNECTION"
        return 0
    elif [[ $UP -eq 1 ]] || [[ $HAS_IP -eq 1 ]]; then
        _blinkjob_start "$GPIO_CONNECTION"
        return 2
    else
        _blinkjob_kill
        setl "$GPIO_CONNECTION"
        return 1
    fi
}

function main() {
    while true; do
        do_wifi
        do_ping $?
        sleep "$TEST_INTERVAL"
    done
}

function graceful_exit() {
    echo ""
    echo "WARN Got SIGINT"
    kill "$MAIN_JOB"
    _blinkjob_kill
    goodbye
    teardown_pins
    exit
}

trap graceful_exit INT   # When running at command line
trap graceful_exit TERM  # When running as a service

setup_pins
greet
main &
MAIN_JOB=$!

sleep infinity