Get rid of potential temp file vulnerability

Also address https://github.com/koalaman/shellcheck/wiki/SC2086 in curl call

Author: ThomasKaiser

check_mk_telegram-notify.sh

@@ -9,48 +9,28 @@
 
 # Telegram API Token
 # Find telegram bot named "@botfarther", type /mybots, select your bot and select "API Token" to see your current token
-TOKEN=$NOTIFY_PARAMETER_1
+TOKEN=${NOTIFY_PARAMETER_1}
 
 # Telegram Chat-ID or Group-ID
 # Open "https://api.telegram.org/bot<YOUR_TOKEN>/getUpdates" inside your Browser and send a HELLO to your bot, refresh side
-CHAT_ID=$NOTIFY_PARAMETER_2
-
-# Write Check_MK output to a temporary file, delete depricated macros and create variable OUTPUT
-env | grep NOTIFY_ | grep -v "This macro is deprecated" | sort > $OMD_ROOT/tmp/telegram.out
-OUTPUT=$OMD_ROOT/tmp/telegram.out
-
-# Read OUTPUT variable and create some more variables for every text-part you want to use afterwards
-HOSTNAME=$(grep NOTIFY_HOSTNAME $OUTPUT | cut -d'=' -f2)
-HOSTALIAS=$(grep NOTIFY_HOSTALIAS $OUTPUT | cut -d'=' -f2)
-WHAT=$(grep NOTIFY_WHAT $OUTPUT | cut -d'=' -f2)
-NOTIFICATIONTYPE=$(grep NOTIFY_NOTIFICATIONTYPE $OUTPUT | cut -d'=' -f2)
-SERVICEDESC=$(grep NOTIFY_SERVICEDESC $OUTPUT | cut -d'=' -f2)
-SERVICEOUTPUT=$(grep NOTIFY_SERVICEOUTPUT $OUTPUT | cut -d'=' -f2)
-HOSTOUTPUT=$(grep NOTIFY_HOSTOUTPUT $OUTPUT | cut -d'=' -f2)
-PREVIOUSHOSTHARDSHORTSTATE=$(grep NOTIFY_PREVIOUSHOSTHARDSHORTSTATE $OUTPUT | cut -d'=' -f2)
-HOSTSHORTSTATE=$(grep NOTIFY_HOSTSHORTSTATE $OUTPUT | cut -d'=' -f2)
-PREVIOUSSERVICEHARDSHORTSTATE=$(grep NOTIFY_PREVIOUSSERVICEHARDSHORTSTATE $OUTPUT | cut -d'=' -f2)
-SERVICESHORTSTATE=$(grep NOTIFY_SERVICESHORTSTATE $OUTPUT | cut -d'=' -f2)
-SHORTDATETIME=$(grep NOTIFY_SHORTDATETIME $OUTPUT | cut -d'=' -f2)
-HOST_ADDRESS_4=$(grep NOTIFY_HOST_ADDRESS_4 $OUTPUT | cut -d'=' -f2)
-HOST_ADDRESS_6=$(grep NOTIFY_HOST_ADDRESS_6 $OUTPUT | cut -d'=' -f2)
+CHAT_ID=${NOTIFY_PARAMETER_2}
 
 # Create a MESSAGE variable to send to your Telegram bot
-MESSAGE="$HOSTNAME ($HOSTALIAS)%0A"
-MESSAGE+="$WHAT $NOTIFICATIONTYPE%0A%0A"
-if [[ $WHAT == "SERVICE" ]]; then
-        MESSAGE+="$SERVICEDESC%0A"
-        MESSAGE+="State changed from $PREVIOUSSERVICEHARDSHORTSTATE to $SERVICESHORTSTATE%0A"
-        MESSAGE+="$SERVICEOUTPUT%0A"
+MESSAGE="${NOTIFY_HOSTNAME} (${NOTIFY_HOSTALIAS})%0A"
+MESSAGE+="${NOTIFY_WHAT} ${NOTIFY_NOTIFICATIONTYPE}%0A%0A"
+if [[ ${NOTIFY_WHAT} == "SERVICE" ]]; then
+        MESSAGE+="${NOTIFY_SERVICEDESC}%0A"
+        MESSAGE+="State changed from ${NOTIFY_PREVIOUSHOSTHARDSHORTSTATE} to ${NOTIFY_SERVICESHORTSTATE}%0A"
+        MESSAGE+="${NOTIFY_SERVICEOUTPUT}%0A"
 else
-        MESSAGE+="State changed from $PREVIOUSHOSTHARDSHORTSTATE to $HOSTSHORTSTATE%0A"
-        MESSAGE+="$HOSTOUTPUT%0A"
+        MESSAGE+="State changed from ${NOTIFY_PREVIOUSHOSTHARDSHORTSTATE} to ${NOTIFY_HOSTSHORTSTATE}%0A"
+        MESSAGE+="${NOTIFY_HOSTOUTPUT}%0A"
 fi
-MESSAGE+="%0AIPv4: $HOST_ADDRESS_4 %0AIPv6: $HOST_ADDRESS_6%0A"
-MESSAGE+="$SHORTDATETIME"
+MESSAGE+="%0AIPv4: ${NOTIFY_HOST_ADDRESS_4} %0AIPv6: ${NOTIFY_HOST_ADDRESS_6}%0A"
+MESSAGE+="${NOTIFY_SHORTDATETIME}"
 
 # Send message to Telegram bot
-curl -s -X POST "https://api.telegram.org/bot$TOKEN/sendMessage" -d chat_id=$CHAT_ID -d text="$MESSAGE" >> /dev/null
+curl -s -X POST "https://api.telegram.org/bot${TOKEN}/sendMessage" -d chat_id="${CHAT_ID}" -d text="${MESSAGE}" >> /dev/null
 
 # End of script
 exit 0