Windows like services development in LINUX using MONO?

Question

I just moved from .net development to LINUX MONO development... and i don have much experience with linux dev earlier..

1. I have a requirement to create a background service (like windows services) in mono c#.. is it possible..

2. And is it possible to access the LINUX native APIs from mono c#. (like winAPI calls from win c#)..

Answer 1

I use scripts, so I can capture the exit code and use it to perform automated updates and things. It also restarts itself if it crashes, and e-mails you when it restarts with the last x lines of the log file.

/etc/init.d/MyMonoApp

#!/bin/sh
#/etc/init.d/MyMonoApp
#

APP_NAME="MyMonoApp"
APP_PATH="/home/mono/MyMonoApp"

APP_USER=mono

case "$1" in
  start)


        echo "Starting $APP_NAME"

        start-stop-daemon --start \
                          --background \
                          --make-pidfile \
                          --pidfile /var/run/$APP_NAME.pid \
                          --chuid $APP_USER \
                          --exec "$APP_PATH/$APP_NAME"
    ;;
  stop)

        echo "Stopping $APP_NAME"
                start-stop-daemon -o  --stop \
                --pidfile /var/run/$APP_NAME.pid

    ;;
  *)
    echo "Usage: /etc/init.d/$APP_NAME {start|stop}"
    exit 1
    ;;
esac

exit 0

/home/mono/MyMonoApp

#!/bin/sh
#!/home/mono/MyMonoApp

APP_NAME=`basename $0`
APP_DIR=`dirname $0`
HOSTNAME=`hostname`

cd $APP_DIR

tail --lines=300 output.log  | mail -s "MyMonoApp $HOSTNAME:$APP_NAME STARTED" "[email protected]"

exitcode=0
until [ $exitcode -eq 9 ]
do
        startdate="$(date +%s)"
        /usr/local/bin/mono MyMonoApp.exe $HOSTNAME:$APP_NAME > output.log
        exitcode=$?
        enddate="$(date +%s)"

        echo "EXIT CODE = $exitcode" >> output.log

        cp -f output.log output.log.1
        elapsed_seconds="$(expr $enddate - $startdate)"
        echo "Elapsed seconds $elapsed_seconds"


        subject="EXIT CODE: $exitcode"
        echo "BASH: Exit Code = $exitcode"

        if [ $exitcode -eq 6 ] #Restart
        then
          subject="RESTART"
        elif [ $exitcode -eq 7 ] #Previous version
        then
          subject="PREVIOUS VERSION"
          cp -fv MyMonoApp.exe_previous MyMonoApp.exe
        elif [ $exitcode -eq 8 ] #Update
        then
          subject="SOFTWARE UPDATE"
          cp -fv MyMonoApp.exe MyMonoApp.exe_previous
          mv -fv MyMonoApp.exe_new MyMonoApp.exe
        elif [ $exitcode -eq 9 ] #Shutdown
        then
          subject="SHUTDOWN"
        fi


        if [ $elapsed_seconds -ge 10 ]  #been running for longer than 10 seconds
        then
                tail --lines=300 output.log  | mail -s "MyMonoApp $HOSTNAME:$APP_NAME $subject" "[email protected]"
                sleep 1  # tiny delay to let things settle
        else
                sleep 5  # delay to protect against eating the CPU resourses
        fi


done

Note: if you close the app using the init.d script, it will kill the process, rather than signal it to cleanly close.