diff --git a/README.md b/README.md index 6bf0639..4047938 100644 --- a/README.md +++ b/README.md @@ -1,6 +1,8 @@ # metrics.sh -metrics.sh is a metrics collection and fowarding daemon implemented in portable shell scripts. A simple interface based on hooks allows for writing custom metrics collectors. +metrics.sh is a lightweight metrics collection and fowarding utility implemented in portable POSIX compliant shell scripts. An elegant interface based on hooks enables writing custom metric collectors and forwarders in a transparent way. + +Besides having a low impact on system resources, which makes metric.sh a suitable solution for running in virtual environments and servers with limited capacities, simplicty is the main goal of this project, hence its documentation shall fit in a single README. ## Usage diff --git a/init.d/metrics.sh b/init.d/metrics.sh index c262505..1606a1c 100644 --- a/init.d/metrics.sh +++ b/init.d/metrics.sh @@ -1,157 +1,90 @@ -#! /bin/sh +#!/bin/sh ### BEGIN INIT INFO # Provides: metrics.sh -# Required-Start: $remote_fs $syslog -# Required-Stop: $remote_fs $syslog -# Should-Start: $network -# Should-Stop: $network +# Required-Start: $local_fs $network $named $time $syslog +# Required-Stop: $local_fs $network $named $time $syslog # Default-Start: 2 3 4 5 # Default-Stop: 0 1 6 # Short-Description: Start and stop metrics.sh # Description: Controls the metrics daemon "metrics.sh" ### END INIT INFO -# Author: Patrick Stadler +RUNAS= +ARGS= NAME=metrics.sh -DAEMON=/usr/bin/$NAME -DAEMON_ARGS="" + PIDFILE=/var/run/$NAME.pid -SCRIPTNAME=/etc/init.d/$NAME +LOGFILE=/var/log/$NAME.log # Exit if the package is not installed [ -x "$DAEMON" ] || exit 0 -# Read configuration variable file if it is present -[ -r /etc/default/$NAME ] && . /etc/default/$NAME - -# Load the VERBOSE setting and other rcS variables -. /lib/init/vars.sh - -# Define LSB log_* functions. -# Depend on lsb-base (>= 3.2-14) to ensure that this file is present -# and status_of_proc is working. -. /lib/lsb/init-functions - -# -# Function that starts the daemon/service -# -do_start() -{ - # Return - # 0 if daemon has been started - # 1 if daemon was already running - # 2 if daemon could not be started - start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON --test > /dev/null \ - || return 1 - start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON -- \ - $DAEMON_ARGS \ - || return 2 - # Add code here, if necessary, that waits for the process to be ready - # to handle requests from services started subsequently which depend - # on this one. As a last resort, sleep for some time. +start() { + if [ -f $PIDFILE ] && kill -0 $(cat $PIDFILE); then + echo 'Service already running' >&2 + return 1 + fi + echo 'Starting serviceā€¦' >&2 + local CMD="$SCRIPT &> \"$LOGFILE\" & echo \$!" + su -c "$CMD $ARGS" $RUNAS > "$PIDFILE" + echo 'Service started' >&2 } -# -# Function that stops the daemon/service -# -do_stop() -{ - # Return - # 0 if daemon has been stopped - # 1 if daemon was already stopped - # 2 if daemon could not be stopped - # other if a failure occurred - start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 --pidfile $PIDFILE --name $NAME - RETVAL="$?" - [ "$RETVAL" = 2 ] && return 2 - # Wait for children to finish too if this is a daemon that forks - # and if the daemon is only ever run from this initscript. - # If the above conditions are not satisfied then add some other code - # that waits for the process to drop all resources that could be - # needed by services started subsequently. A last resort is to - # sleep for some time. - start-stop-daemon --stop --quiet --oknodo --retry=0/30/KILL/5 --exec $DAEMON - [ "$?" = 2 ] && return 2 - # Many daemons don't delete their pidfiles when they exit. - rm -f $PIDFILE - return "$RETVAL" +stop() { + if [ ! -f "$PIDFILE" ] || ! kill -0 $(cat "$PIDFILE"); then + echo 'Service not running' >&2 + return 1 + fi + echo 'Stopping serviceā€¦' >&2 + kill -15 $(cat "$PIDFILE") && rm -f "$PIDFILE" + echo 'Service stopped' >&2 } -# -# Function that sends a SIGHUP to the daemon/service -# -do_reload() { - # - # If the daemon can reload its configuration without - # restarting (for example, when it is sent a SIGHUP), - # then implement that here. - # - start-stop-daemon --stop --signal 1 --quiet --pidfile $PIDFILE --name $NAME - return 0 +status() { + printf "%-50s" "Checking $NAME..." + if [ -f $PIDFILE ]; then + PID=$(cat $PIDFILE) + if [ -z "$(ps axf | grep ${PID} | grep -v grep)" ]; then + printf "%s\n" "The process appears to be dead but pidfile still exists" + else + echo "Running, the PID is $PID" + fi + else + printf "%s\n" "Service not running" + fi +} + +uninstall() { + echo -n 'Are you really sure you want to uninstall this service? That cannot be undone. [yes|No] ' + local SURE + read SURE + if [ "$SURE" = "yes" ]; then + stop + rm -f "$PIDFILE" + echo "Notice: log file was not removed: '$LOGFILE'" >&2 + update-rc.d -f remove + rm -fv "$0" + fi } case "$1" in start) - [ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME" - do_start - case "$?" in - 0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;; - 2) [ "$VERBOSE" != no ] && log_end_msg 1 ;; - esac - ;; + start + ;; stop) - [ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME" - do_stop - case "$?" in - 0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;; - 2) [ "$VERBOSE" != no ] && log_end_msg 1 ;; - esac - ;; + stop + ;; status) - status_of_proc "$DAEMON" "$NAME" && exit 0 || exit $? - ;; - #reload|force-reload) - # - # If do_reload() is not implemented then leave this commented out - # and leave 'force-reload' as an alias for 'restart'. - # - #log_daemon_msg "Reloading $DESC" "$NAME" - #do_reload - #log_end_msg $? - #;; - restart|force-reload) - # - # If the "reload" option is implemented then remove the - # 'force-reload' alias - # - log_daemon_msg "Restarting $DESC" "$NAME" - do_stop - case "$?" in - 0|1) - do_start - case "$?" in - 0) log_end_msg 0 ;; - 1) log_end_msg 1 ;; # Old process is still running - *) log_end_msg 1 ;; # Failed to start - esac + status ;; - *) - # Failed to stop - log_end_msg 1 + uninstall) + uninstall + ;; + restart) + stop + start ;; - esac - ;; *) - #echo "Usage: $SCRIPTNAME {start|stop|restart|reload|force-reload}" >&2 - echo "Usage: $SCRIPTNAME {start|stop|status|restart|force-reload}" >&2 - exit 3 - ;; + echo "Usage: $0 {start|stop|status|restart|uninstall}" esac - -: \ No newline at end of file