ircbot: Restart on failure, do not self-exec if running under systemd

Makefile

@@ -10,6 +10,7 @@ SYSTEMD_UNIT_DIR = /lib/systemd/system
 rc: install
 	@echo installing ircbot to /etc/rc.d
 	@cp -f services/rc/ircbot /etc/rc.d
+	@chmod 555 /etc/rc.d/ircbot
 	@echo enabling ircbot
 	@rcctl enable ircbot
 	@echo not starting ircbot -- configure it then run `rcctl start ircbot` as root

check_ircd

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 botname=nagiosbot
 host=localhost
@@ -28,7 +28,8 @@ function delay {
 
 SECONDS=0
 echo "NICK $botname
-USER $botname 8 * : $botname" | nc -i 1 -q $crit -w $crit $host $port 2>&1 > /dev/null
+USER $botname 8 * : $botname
+QUIT" | nc -i 1 -w $crit $host $port 2>&1 > /dev/null
 exit=$?
 if [ ! "$exit" == 0 ]; then
 	echo "IRCd CRITICAL: $host: connection failed"

ircbot.sh

@@ -8,6 +8,7 @@ if ! test -r $conf; then
     echo "cannot read configuration file, exiting"
     exit 1
 else
+    # shellcheck source=ircbot.conf.default
     . $conf
 fi
 
@@ -21,7 +22,15 @@ connect() {
     echo "PRIVMSG $chan : $joinmsg" >> $inputf
 }
 reconnect() {
-    exec $0
+    if command -v systemctl >/dev/null; then
+        # NOTE: systemd is configured to restart the service, so simply dying
+        #       with a non-zero exit code is enough to effectively reconnect.
+        exit 2
+    else
+        # FIXME: We need to make sure we are only running one instance of the
+        #        script at a time. This exec is therefore problematic.
+        exec $0
+    fi
 }
 delay() {
     while read line
@@ -46,7 +55,7 @@ loop &
 
 tail -f $inputf | delay | nc $server $port | while read msg
 do
-    echo "$msg" | tee $logf
+    echo "$msg" | tee -a $logf
     case "$msg" in
         *'PING'*) echo "$msg" | sed 's/PING/PONG/' >> $inputf
         ;;

services/systemd/ircbot.service

@@ -5,6 +5,7 @@ Description=Anarchyplanet IRC Bot
 User=nagios
 Group=nagios
 ExecStart=/usr/local/bin/ircbot.sh
+Restart=on-failure
 
 [Install]
 WantedBy=multi-user.target