#!/bin/sh
# $Id: nws-hostadmin,v 1.17 2004/06/28 21:42:06 graziano Exp $

# This is a script that assists in the remote maintenance of NWS hosts. 

commands=",add,cycle,forget,halt,kill,purge,revive,start,test,"
# Make sure argv[1] is a valid command
if [ $# -eq 0 -o `echo "$commands" | grep -ic ",$1[a-z]*,"` -eq 0 ]; then
	echo 'nws-hostadmin <command> [[<switches>] <hosts> ...]'
	echo '  where <command> is one of:' `echo $commands | sed 's/,/ /g'`
	echo '        <switches> is -bBmM <path> -lL <login> -sS <switches>'
	echo '        <hosts> is machine[:<host type>[:<port>][,<host type>[:port]...]]'
	exit 1
fi

command="$1"
shift

hostDB="$HOME/.nwshosts"
binPathDefault='$HOME/nws/bin'  ;# Single quotes: $HOME on *remote* machine.
loginDefault="$USER"
methodPathDefault="ssh"
switchesDefault=""
dollar="\$"

for var in binPath hostSpec login methodPath switches argVar results; do
	eval $var=""
done

# For each host spec...
for arg in "$@"; do
	if [ -n "$argVar" ]; then
		eval "$argVar='$arg'"
		argVar=""
	elif [ "$arg" = "-b" ]; then
		argVar="binPath"
	elif [ "$arg" = "-B" ]; then
		argVar="binPathDefault"
	elif [ "$arg" = "-f" ]; then
		argVar="hostDB"
	elif [ "$arg" = "-l" ]; then
		argVar="login"
	elif [ "$arg" = "-L" ]; then
		argVar="loginDefault"
	elif [ "$arg" = "-m" ]; then
		argVar="methodPath"
	elif [ "$arg" = "-M" ]; then
		argVar="methodPathDefault"
	elif [   "$arg" = "-s" ]; then
		argVar="switches"
	elif [ "$arg" = "-S" ]; then
		argVar="switchesDefault"
	else
		hostSpec="$arg"
	fi

	if [ -z "$hostSpec" ]; then
		# Keep parsing switches until we see a host specification.
		continue
	fi

	# Set all variables that the user didn't specify to their default values.
	for var in binPath login methodPath switches; do
		value=`eval echo "$dollar$var"`
		if [ -z "$value" ]; then
			value=`eval echo "$dollar${var}Default"`
			eval "$var='$value'"
		fi
	done

	# Split host spec into a machine name and a list of hosts.  If the user
	# specified no hosts, get any host set from the host db or
	# default to the standard NWS host set.
	case "$hostSpec" in
	*:*)
		hostSet=`echo $hostSpec | sed 's/^[^:]*://' | sed 's/,/ /g'`
		machine=`echo $hostSpec | sed 's/:.*//'`
		;;
	*)
		hostSet=""
		machine="$hostSpec"
		if [ -r $hostDB ]; then
			hostSet=`grep "^$machine " $hostDB | awk ' {printf $2 " "}'`
		fi
		if [ -z "$hostSet" ]; then
			hostSet="memory:8050 sensor:8060 forecaster:8070"
		fi
		;;
	esac

	for host in $hostSet; do
		# Split host into a type/port pair and determine the exec
		# from the type.
		hostAttrs=`echo $host | sed 's/:/ /'`

		case "$hostAttrs" in
		[fF]*)
			hostExec="nws_forecast"
			hostType="forecaster"
			hostPort=8070
			;;
		[mM]*)
			hostExec="nws_memory"
			hostType="memory"
			hostPort=8050
			;;
		[nN]*)
			hostExec="nws_nameserver"
			hostType="nameserver"
			hostPort=8090
			;;
		[sS]*)
			hostExec="nws_sensor"
			hostType="sensor"
			hostPort=8060
			;;
		esac

		# If hostAttrs includes a port, use it instead of the default.
		hostPort=`echo $hostAttrs $hostPort | awk ' {print $2}'`

		# Determine the current status of the host, if appropriate.
		hostStat=""
		case "$command" in
		[aAfF]*)
			# No test needed.
			;;
		*)
			testOut=`ctrl_host test ${machine}:$hostPort 2>&1 | cat`
			for healthWord in healthy dead unresponsive sick confused; do
				case "$testOut" in
				*$healthWord*)
					hostStat="$healthWord"
					break
					;;
				esac
			done
			;;
		esac

		# Process the command.  Each command sets hostStat and
		# either leaves deadStat blank, indicating that the host
		# status has been determined, or
		# sets it to a value for a post-command test.
		deadStat=""
		tempDB=".nwsadmin$$"

		case "$command" in
		[aA]*)
			hostStat="added"
			if [ -r $hostDB ]; then
				if [ `grep -ic "^$machine  *$hostType" $hostDB` -ne 0 ]; then
					hostStat="known"
				fi
			fi
			if [ "$hostStat" != "known" ]; then
				echo "$machine,${hostType}:$hostPort,$binPath,$switches" | \
				awk -F, ' {printf "%-25s %-15s %s %s\n", $1, $2, $3, $4}' >> $hostDB
				sort $hostDB > $tempDB
				mv $tempDB $hostDB
			fi
			;;
		[cC]*)
			if [ "$hostStat" != "dead" ]; then
			# Recursively try to halt, then restart, the host.
			hostStat=`$0 h -l $login ${machine}:${hostType}:$hostPort | awk ' {print $NF}'`
				if [ "$hostStat" != "unhaltable" ]; then
					$0 s -l $login -m $methodPath ${machine}:${hostType}:$hostPort > /dev/null 2>&1
					hostStat="cycled"
					deadStat="uncycled"
				fi
			fi
			;;
    		fF]*)
			hostStat="unknown"
			if [ -r $hostDB ]; then
				if [ `grep -ic "^$machine  *$hostType" $hostDB` -ne 0 ]; then
					grep -v "^$machine  *$hostType" $hostDB > $tempDB
					mv $tempDB $hostDB
					hostStat="forgotten"
				fi
			fi
			;;

		[hH]*)
			if [ "$hostStat" != "dead" ]; then
				ctrl_host halt ${machine}:$hostPort > /dev/null 2>&1
				sleep 2  # Give it some time to exit.
				hostStat="unhaltable"
				deadStat="halted"
			fi
			;;
		[kK]*)
			if [ "$hostStat" != "dead" ]; then
				# We don't know whether the ps on the
				# target host is BSD or SYSV.  This test
				# selects the proper parameter format
				# depending on whether an attempt to
				# invoke ps using BSD parameters
				# succeeds.
				bsdTest="[ \`ps w 2>&1 | grep -c \"^[0-9]\"\` -gt 0 ]"
				psCommand="sh -c 'if $bsdTest; then ps uwx; else ps -fu \$USER; fi'"
				# Note: We assume here that the process
				# we want to kill is the only one that
				# has $hostExec in its name.  This will
				# not be true if $machine is the same one
				# that we're running on (the awk command
				# will show up in the ps output), but
				# we'll only try to kill an already-dead
				# process.
				prePids=`$methodPath -l $login $machine "$psCommand" | awk "/$hostExec/ {print ${dollar}2}"`
				$methodPath -l $login $machine "kill -9 $prePids" > /dev/null 2>&1
				postPids=`$methodPath -l $login $machine "$psCommand" | awk "/$hostExec/ {print ${dollar}2}"`
				if [ "$postPids" != "$prePids" ]; then
					hostStat="killed"
				else
					hostStat="unkillable"
				fi
			fi
			;;
		[pP]*)
			if [ "$hostStat" != "dead" ]; then
				# Recursively try to halt and forget the host.
				hostStat=`$0 h -l $login ${machine}:${hostType}:$hostPort | awk ' {print $NF}'`
				if [ "$hostStat" != "unhaltable" ]; then
					$0 f ${machine}:${hostType}:$hostPort > /dev/null 2>&1
					hostStat="purged"
				fi
			fi
			;;
		[rR]*)
			if [ "$hostStat" = "dead" ]; then
				$0 s -l $login -m $methodPath ${machine}:${hostType}:$hostPort > /dev/null 2>&1
				hostStat="revived"
				deadStat="unrevivable"
			fi
			;;
		[sS]*)
			if [ "$hostStat" = "dead" ]; then
				# Construct the standard switches.  Since
				# we put them on the command line before
				# the user's switches, the user's will
				# take precedence.
				dataDir="nws/$machine"
				defaultSwitches="-p $hostPort -e $dataDir/$hostType.err -l $dataDir/$hostType.log"
				if [ "$hostType" = "memory" ]; then
					defaultSwitches="-d $dataDir $defaultSwitches"
				fi
				# Grab switches from any previous runs.
				# It's debatable that we should retain
				# these, but, again, new switches will
				# take precedence.
				oldSwitches=
				if [ -r $hostDB ]; then
					nwsAttrs=`grep "^$machine  *$hostType" $hostDB`
					if [ -n "$nwsAttrs" ]; then
						binPath=`echo $nwsAttrs | awk ' {print $3}'`
						oldSwitches=`echo $nwsAttrs | sed "s@.*$binPath@@"`
					fi
				fi
				$methodPath -l $login $machine "$binPath/$hostExec $defaultSwitches $oldSwitches $switches &"
				# Delete any existing entry for this host
				# and add a new one.
				$0 f "$machine:$hostType" > /dev/null 2>&1
				if [ -n "$oldSwitches$switches" ]; then
					$0 a -b "$binPath" -s "$oldSwitches $switches" "${machine}:${hostType}:${hostPort}" > /dev/null 2>&1
				else
					$0 a -b "$binPath" "${machine}:${hostType}:${hostPort}" > /dev/null 2>&1
				fi
				hostStat="started"
				deadStat="unstarted"
			fi
			;;
		[tT]*)
			# Nothing more to do.
			;;
		esac

		if [ -n "$deadStat" ]; then
			testOut=`ctrl_host test ${machine}:$hostPort 2>&1 | cat`
			case "$testOut" in
			*dead*)
				hostStat="$deadStat"
				;;
			esac
		fi

		results="${machine}:${hostType}:${hostPort} $hostStat"
		echo "$results"
	done

	for var in binPath hostSpec login methodPath switches; do
		eval $var=""
	done
done

if [ -z "$results" ]; then
	# If the user gave no host specification, apply the arguments to
	# every host in the data base, if it exists.
	if [ -r $hostDB ]; then
		hosts=`awk ' {print $1 " "}' < $hostDB | grep -v '#' |  sort | uniq | awk ' {printf $1 " "}'`
		$0 $command "$@" $hosts
	fi
fi

exit 0