Software Público Brasileiro

#!/bin/bash

# Let runit capture all script error messages
exec 2>&1

readonly current_pidfile=<%= node['gitlab']['unicorn']['pidfile'] %>
readonly oldbin_pidfile=${current_pidfile}.oldbin
readonly unicorn_wait_start=1 # time in seconds
readonly unicorn_poll_alive=1 # time in seconds

function main
{
  cd /opt/gitlab/embedded/service/gitlab-rails
  find_us_a_unicorn
  trap_signals
  wait_for_unicorn_to_exit
}

function find_us_a_unicorn
{
  adopt ${current_pidfile}
  if [[ ${unicorn_pid} ]]; then
    echo "adopted existing unicorn master ${unicorn_pid}"
    return
  fi

  adopt ${oldbin_pidfile}
  if [[ ${unicorn_pid} ]]; then
    echo "adopted existing oldbin unicorn master ${unicorn_pid}"
    return
  fi

  echo "starting new unicorn master"
  start_unicorn_master
  sleep ${unicorn_wait_start}

  adopt ${current_pidfile}
  if [[ ${unicorn_pid} ]]; then
    echo "adopted new unicorn master ${unicorn_pid}"
    return
  fi

  echo "failed to start a new unicorn master"
  exit
}

function adopt
{
  local pid=$(cat $1 2>/dev/null)
  if alive ${pid} && is_unicorn ${pid}; then
    readonly unicorn_pid=${pid}
  fi
}

function alive
{
  kill -0 $1 > /dev/null 2>&1
}

function is_unicorn
{
  ps -p $1 -o args | grep -q unicorn
}

function start_unicorn_master
{
  chpst -P -U <%= node['gitlab']['user']['username'] %> -u <%= node['gitlab']['user']['username'] %> /usr/bin/env HOME="<%= node['gitlab']['user']['home'] %>" /opt/gitlab/embedded/bin/bundle exec unicorn -D -E <%= node['gitlab']['gitlab-rails']['environment'] %> -c <%= File.join(node['gitlab']['gitlab-rails']['dir'], "etc", "unicorn.rb") %> /opt/gitlab/embedded/service/gitlab-rails/config.ru
}

function trap_signals
{
  # Forward all common runit signals except:
  # - HUP which we handle below;
  # - KILL which cannot be caught.
  for sig in STOP CONT ALRM INT QUIT USR1 USR2 TERM; do
    trap "forward_signal ${sig}" ${sig}
  done

  # Omnibus-ctl does not have a subcommand that sends USR2 but it can send HUP.
  # To allow for reloading unicorn from the command line, translate HUP to
  # USR2.
  trap "echo 'wrapper received HUP'; forward_signal USR2" HUP
}

function forward_signal
{
  echo "forwarding $1 to unicorn master ${unicorn_pid}"
  kill -$1 ${unicorn_pid}
}

function wait_for_unicorn_to_exit
{
  while sleep ${unicorn_poll_alive}; do
    alive ${unicorn_pid} || break
  done
}

main
echo "wrapper for unicorn master ${unicorn_pid} exiting"