gitlab_ci_runner

#! /bin/bash

### BEGIN INIT INFO
# Provides:          gitlab-ci-runner
# Required-Start:    $local_fs $remote_fs $network $syslog
# Required-Stop:     $local_fs $remote_fs $network $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: GitLab CI Runner init.d script
# Description:       Enables automatic start of runners at boot time in the background.
### END INIT INFO

APP_ROOT="/home/gitlab_ci_runner/gitlab-ci-runner"
APP_USER="gitlab_ci_runner"
PID_PATH="$APP_ROOT/tmp/pids"
PROCESS_NAME="ruby ./bin/runner"
RUNNERS_PID="$PID_PATH/runners.pid"
RUNNERS_NUM=1 # number of runners to spawn
START_RUNNER="nohup bundle exec ./bin/runner"
NAME="gitlab-ci-runner"
DESC="GitLab CI runner"
RUNNERS_REGISTERED=0
RUNNERS_RUNNING=0
INIT_LOG="/var/log/gitlab_ci_runner.log"

check_pid() {
  # Number of registered runners in PID file
  RUNNERS_REGISTERED=0
  # Number of active runner processes from PID file
  RUNNERS_RUNNING=0

  if [ -f $RUNNERS_PID ]; then
    # Registered
    RUNNERS_REGISTERED=`cat $RUNNERS_PID | wc -l`

    # Running
    while read pid; do
      if [ -d /proc/$pid ]; then
        # Process is running
        ((RUNNERS_RUNNING++))
      fi
    done < $RUNNERS_PID
  fi

  echo "Number of registered runners in PID file=$RUNNERS_REGISTERED"
  echo "Number of running runners=$RUNNERS_RUNNING"
}

execute() {
  sudo -u $APP_USER -H bash -l -c "$1"
}

start() {
  cd $APP_ROOT
  check_pid
  if [ "$RUNNERS_REGISTERED" -ne 0 -o "$RUNNERS_RUNNING" -ne 0 ]; then
    # Program is running, Exit with error code.
    echo "Error! $DESC(s) ($NAME) appear to be running already! Try stopping them first. Exiting."
    exit 1
  else
    if [ `whoami` = root ]; then
      [ ! -f $PID_PATH ] && execute "mkdir -p $PID_PATH"
      [ -f $RUNNERS_PID ] && execute "rm -f $RUNNERS_PID"

      # Spawn runners
      for (( i=1; i<=$RUNNERS_NUM; i++ ))
      do
        # Check log file
        if [ ! -f $INIT_LOG ]; then
          touch $INIT_LOG
          chown $APP_USER $INIT_LOG
        fi
       
        echo "Starting runner #$i"
        execute "$START_RUNNER  >> $INIT_LOG 2>&1 & echo \$! >> $RUNNERS_PID"
      done
      
      echo "SUCCESS: Started $RUNNERS_NUM $DESC(s)."
    fi
  fi
}

stop() {
  check_pid
  # Exit if there are no runners
  if [ $RUNNERS_REGISTERED -eq 0 -a  $RUNNERS_RUNNING -eq 0 ]; then
    echo "No runners have been found. Exiting."
  fi

  # Runners found. Check if there are any ghost runners.
  KILL_GHOSTS=0;
  if [ $RUNNERS_REGISTERED -ne $RUNNERS_RUNNING ]; then
    echo "WARNING: Numbers of registered runners don't match number of running runners. Will try to stop them all"
    echo "Registered runners=$RUNNERS_REGISTERED"
    echo "Running runners=$RUNNERS_RUNNING"
    KILL_GHOSTS=1;
  fi

  echo -n "Trying to stop registered runners..."
  if [ $RUNNERS_REGISTERED -gt 0 ]; then
    execute "cat $RUNNERS_PID | xargs kill -USR2"
    rm -f $RUNNERS_PID
    echo "OK"
  else
    echo "FAILED!"
    echo "Couldn't stop registered runners as there is no record of such in $RUNNERS_PID file".
  fi

  if [ $KILL_GHOSTS -eq 1 ]; then
    echo -ne "Trying to kill ghost runners..."
    ps -C "$PROCESS_NAME" -o "%p" h | xargs kill -USR2
    [ $? -eq 0 ] && echo "OK"
  else
    echo "No ghost runners have been found.This is good."
  fi
}

status() {
  echo "Here is what we have at the moment:"
  check_pid
}

## Check to see if we are running as root first.
if [ "$(id -u)" != "0" ]; then
  echo "This script must be run as root"
  exit 1
fi

case "$1" in
  start)
    start
    ;;
  stop)
    stop
    ;;
  restart)
    stop
    start
    ;;
  status)
    status
    ;;
  *)
    echo "Usage: sudo service gitlab_ci_runner {start|stop|restart|status}" >&2
    exit 1
    ;;
esac

exit 0