website/input/projects/ultimatenotifier.md

title: Ultimate Notifier Script title_de: Ultimate Notifier Script description: Sending Push Notifications to an iPhone from a Bash Script parent: stuff position: 70 comments: true flattr: true compat: notifier date: 2012-12-31

update: 2013-02-11

The service Ultimate Notifier allows you to send Push-Notification to your iPhone easily. Based on this, you can write shell scripts that are executed regularly via cron. This could inform you about a changed public IP. To do this, save this script somewhere:

#!/bin/sh

ipfile=".currentip"
service="ifconfig.me"
user="username"
pass="password"
message="IP:"

ip=`curl -s $service`
touch $ipfile
lastip=`cat $ipfile`
if [ "$ip" != "$lastip" ]; then
    echo "New public IP. Sending notification!"
    curl -s "https://www.ultimatenotifier.com/items/User/send/${user}/message=${message}%20${ip}/password=${pass}"
fi
cp /dev/null $ipfile
echo $ip > $ipfile

It gets the current public IP via ifconfig.me and compares it to the IP stored in a file named .currentip. If they differ, a Push-Notification will be sent and the new IP stored.

With the command

crontab -e

You can add a cronfile entry. To execute the script every 30 minutes, use this:

*/30 * * * * /Users/anon/bin/ipnotify.sh

You can find the code on GitHub, too!

Of course, you can extend this principle. This script is called every 5 minutes on my server to notify me about eventual problems.

#!/bin/bash

# Checks for Health of Server and sends notifications to iPhone in case of error
# Checks for:
# - HDD Temperature
# - HDD Space
# - CPU Usage
# Sends a notification via UltimateNotifier
# Depends on bash, wget, hddtemp, grep, awk, sed, ps, sort and head.

# ------------------------------
# ------------------------------

# Your UltimateNotifier Password
UNUsername="YourUserName"
UNPassword="YourPassWord"

# Check for free space
hddMountPoint="bay" # greps for this in mounted hdds
maxPercentFull=75 # minimum percentage to send notification

# Check for CPU Usage of processes
maxCpuUsage=750 # Is in tenths of a percent (420 => 42%)

# Checks hdd temperature
# Depends on hddtemp tool
hddDevice="/dev/sda"
maxHddTemp=50

# ------------------------------
# ------------------------------

# Set $message to your Message and then call this...
function sendNotification {
    wget "https://www.ultimatenotifier.com/items/User/send/${UNUsername}/message=${message}/password=${UNPassword}" -O /dev/null -q
    echo "$message"
}

# ------------------------------
# ------------------------------

# Check for hdd temperature
hddTemp=`/usr/sbin/hddtemp ${hddDevice} | awk '{print $4}' | awk -F '°' '{print $1}'`
if [ $hddTemp -gt $maxHddTemp ]; then
    message="Marvin's HDD has reached ${hddTemp}°C!"
    sendNotification
fi

# Check for free space on hdd
spaceUsed=`df -h | grep ${hddMountPoint} | awk '{print $5}' | sed 's/%//'`
if [ $spaceUsed -gt $maxPercentFull ]; then
    message="Marvin's HDD is ${spaceUsed}% full!"
    sendNotification
fi

# Check for most cpu intensive process, report if usage too high
processName=`ps -e -o cp,args | sed -e 's/^[ \\t]*//' | awk -F " " '{print $1, $2}' | sed -e '1d' | sort -rn | head -1 | awk '{print $2}'`
processUsage=`ps -e -o cp,args | sed -e 's/^[ \\t]*//' | awk -F " " '{print $1, $2}' | sed -e '1d' | sort -rn | head -1 | awk '{print $1}'`
if [ $processUsage -gt $maxCpuUsage ]; then
    processUsage=`echo "${processUsage} / 10.0" | bc -q`
    message="${processName} needs ${processUsage}% CPU!"
    sendNotification
fi

lang: de

{{ page.title_de }}

Der Dienst Ultimate Notifier erlaubt es relativ problemlos, zum Beispiel mittels curl Push-Notifications an ein iPhone zu senden. Darauf basierend können Shell Skripte geschrieben werden, welche regelmäßig als Cron-Job gestartet werden. So kann man sich zum Beispiel über eine geänderte Public IP informieren lassen. Dafür muss dieses Skript irgendwo gespeichert werden:

#!/bin/sh

ipfile=".currentip"
service="ifconfig.me"
user="username"
pass="password"
message="IP:"

ip=`curl -s $service`
touch $ipfile
lastip=`cat $ipfile`
if [ "$ip" != "$lastip" ]; then
    echo "New public IP. Sending notification!"
    curl -s "https://www.ultimatenotifier.com/items/User/send/${user}/message=${message}%20${ip}/password=${pass}"
fi
cp /dev/null $ipfile
echo $ip > $ipfile

Es liest die aktuelle öffentliche IP mittels curl vom Dienst ifconfig.me aus und vergleicht diese mit der zwischengespeicherten IP in einer Datei namens .currentip. Unterscheiden sich die IPs, wird eine Push Notification gesendet und die neue IP gespeichert.

Mit dem Befehl

crontab -e

Kann ein Eintrag ins cronfile hinzugefügt werden, sodass das Skript regelmäßig gestartet wird. Ein Beispiel, für 30 Minuten:

*/30 * * * * /Users/anon/bin/ipnotify.sh

Der Code findet sich auch auf GitHub.

Natürlich kann dieses Prinzip beliebig erweitert werden. Dieses Bash Skript wird auf meinem Server alle 5 Minuten von cron gestartet und berichtet über eventuelle Probleme.

#!/bin/bash

# Checks for Health of Server and sends notifications to iPhone in case of error
# Checks for:
# - HDD Temperature
# - HDD Space
# - CPU Usage
# Sends a notification via UltimateNotifier
# Depends on bash, wget, hddtemp, grep, awk, sed, ps, sort and head.

# ------------------------------
# ------------------------------

# Your UltimateNotifier Password
UNUsername="YourUserName"
UNPassword="YourPassWord"

# Check for free space
hddMountPoint="bay" # greps for this in mounted hdds
maxPercentFull=75 # minimum percentage to send notification

# Check for CPU Usage of processes
maxCpuUsage=750 # Is in tenths of a percent (420 => 42%)

# Checks hdd temperature
# Depends on hddtemp tool
hddDevice="/dev/sda"
maxHddTemp=50

# ------------------------------
# ------------------------------

# Set $message to your Message and then call this...
function sendNotification {
  wget "https://www.ultimatenotifier.com/items/User/send/${UNUsername}/message=${message}/password=${UNPassword}" -O /dev/null -q
  echo "$message"
}

# ------------------------------
# ------------------------------

# Check for hdd temperature
hddTemp=`/usr/sbin/hddtemp ${hddDevice} | awk '{print $4}' | awk -F '°' '{print $1}'`
if [ $hddTemp -gt $maxHddTemp ]; then
  message="Marvin's HDD has reached ${hddTemp}°C!"
  sendNotification
fi

# Check for free space on hdd
spaceUsed=`df -h | grep ${hddMountPoint} | awk '{print $5}' | sed 's/%//'`
if [ $spaceUsed -gt $maxPercentFull ]; then
  message="Marvin's HDD is ${spaceUsed}% full!"
  sendNotification
fi

# Check for most cpu intensive process, report if usage too high
processName=`ps -e -o cp,args | sed -e 's/^[ \\t]*//' | awk -F " " '{print $1, $2}' | sed -e '1d' | sort -rn | head -1 | awk '{print $2}'`
processUsage=`ps -e -o cp,args | sed -e 's/^[ \\t]*//' | awk -F " " '{print $1, $2}' | sed -e '1d' | sort -rn | head -1 | awk '{print $1}'`
if [ $processUsage -gt $maxCpuUsage ]; then
  processUsage=`echo "${processUsage} / 10.0" | bc -q`
  message="${processName} needs ${processUsage}% CPU!"
  sendNotification
fi