notifications: Notify via email and telegram

Provide notification in case of a state change via email and telegram
bot.

The telegram bot is especially helpful in cases where a problem with
email delivery is to be reportet.

Signed-off-by: Tobias Wiese <tobias@tobiaswiese.com>

1 files changed, 89 insertions, 0 deletions

diff --git a/scripts/telegram-host-notification.sh b/scripts/telegram-host-notification.sh
new file mode 100755
index 0000000..5d42709
--- /dev/null
+++ b/scripts/telegram-host-notification.sh
@@ -0,0 +1,89 @@
+#!/bin/sh
+# (C) Tobias Wiese | GPLv2+
+# This file is based on mail-host-notification.sh from Icinga used under GPLv2+ license
+# Except of function urlencode which is Copyright (C) by Brian White (brian@aljex.com) used under MIT license
+# Changes: The script was adapted to send Telegram Messages instead of mail.
+
+PROG="$(basename $0)"
+ICINGA2HOST="$(hostname)"
+
+if [ -z "$(type curl)" ] ; then
+	echo "curl not found in \$PATH. Consider installing it." 2>&1
+	exit 1
+fi
+
+## Function helpers
+urlencode() {
+  local LANG=C i=0 c e s="$1"
+
+  while [ $i -lt ${#1} ]; do
+    [ "$i" -eq 0 ] || s="${s#?}"
+    c=${s%"${s#?}"}
+    [ -z "${c#[[:alnum:].~_-]}" ] || c=$(printf '%%%02X' "'$c")
+    e="${e}${c}"
+    i=$((i + 1))
+  done
+  echo "$e"
+}
+
+## Keep formatting in sync with telegram-service-notification.sh
+for P in DATE HOSTNAME HOSTDISPLAYNAME HOSTOUTPUT HOSTSTATE USERCHATID TYPE
+do
+	eval "PAR=\$${P}"
+
+	if [ ! "$PAR" ] ; then
+		echo "Required parameter '$P' is missing." >&2
+		exit 1
+	fi
+done
+
+## Build the notification message
+NOTIFICATION_MESSAGE=`cat << EOF
+***** Host Monitoring on $ICINGA2HOST *****
+
+$HOSTDISPLAYNAME is $HOSTSTATE!
+
+Info:    $HOSTOUTPUT
+
+When:    $DATE
+Host:    $HOSTNAME
+EOF
+`
+
+## Check whether IPv4 was specified.
+if [ -n "$ADDRESS" ] ; then
+	NOTIFICATION_MESSAGE="$NOTIFICATION_MESSAGE
+IPv4:   $ADDRESS"
+fi
+
+## Check whether IPv6 was specified.
+if [ -n "$ADDRESS6" ] ; then
+	NOTIFICATION_MESSAGE="$NOTIFICATION_MESSAGE
+IPv6:   $ADDRESS6"
+fi
+
+## Check whether author and comment was specified.
+if [ -n "$COMMENT" ] ; then
+	NOTIFICATION_MESSAGE="$NOTIFICATION_MESSAGE
+
+Comment by $AUTHOR:
+	$COMMENT"
+fi
+
+## Check whether Icinga Web 2 URL was specified.
+if [ -n "$ICINGAWEB2URL" ] ; then
+	NOTIFICATION_MESSAGE="$NOTIFICATION_MESSAGE
+
+$ICINGAWEB2URL/monitoring/host/show?host=$(urlencode "$HOSTNAME")"
+fi
+
+## Check whether verbose mode was enabled and log to syslog.
+if [ "$VERBOSE" = "true" ] ; then
+	logger "$PROG sends Telegram => $CHATID"
+fi
+
+## Send message via telegram
+curl -X POST "https://api.telegram.org/bot${TOKEN}/sendMessage" \
+	--data-urlencode "chat_id=$USERCHATID" \
+	--data-urlencode "text=$NOTIFICATION_MESSAGE" \
+	--data-urlencode "disable_web_page_preview=true"