start rails unicorn web server in foreground

rails_unicorn_start_fg.bash

#!/usr/bin/env bash

# Run unicorn in the foreground and customize how it runs.
#
# Usage: ./script/start_rails_fg.bash
#        ./script/start_rails_fg.bash --help
# supports these env variables: UNICORN_PID
#                               UNICORN_LISTEN
#                               UNICORN_STDERR_PATH
#                               UNICORN_STDOUT_PATH
#                               UNICORN_TIMEOUT
#                               UNICORN_WORKERS
#

function wf_fg_usage() {
  cat <<END
Usage: ./script/start_rails_fg.bash
supported env vars:
UNICORN_PID=/opt/workfeed/tmp/pids/unicorn.pid;
UNICORN_LISTEN=/tmp/workfeed.unicorn.sock;
UNICORN_STDERR_PATH=false;
UNICORN_STDOUT_PATH=false;
UNICORN_TIMEOUT=200000;
UNICORN_WORKERS=1;
END
} >&2

[[ $1 == '--help' ]] && { wf_fg_usage; exit 0; };
[[ $1 ]] && { wf_fg_usage; exit 1; };

function wf_fg_stop_bg_unicorn() {
  printf "%s\n" "stopping the unicorns"
  sudo stop workfeed 2> /dev/null;
}

function wf_fg_set_env_vars() {
  export UNICORN_PID=${UNICORN_PID:-'/opt/workfeed/tmp/pids/unicorn.pid'}
  export UNICORN_LISTEN=${UNICORN_LISTEN:-'/tmp/workfeed.unicorn.sock'}
  export UNICORN_STDERR_PATH=${UNICORN_STDERR_PATH:-false}
  export UNICORN_STDOUT_PATH=${UNICORN_STDOUT_PATH:-false}
  export UNICORN_TIMEOUT=${UNICORN_TIMEOUT:-200000} # long timeout to be able to run with debugger
  export UNICORN_WORKERS=${UNICORN_WORKERS:-1}
}

function wf_fg_start_rails() {
  declare -i rails_load_env_seconds=15; # measured with `time bundle exec rails runner 'puts Rails.version'`
  printf "%s: %d\n" "starting rails in foreground, wait seconds" $rails_load_env_seconds
  declare -r local_unicorn_config='/opt/workfeed/config/unicorn.rb'

  [[ ! -f $local_unicorn_config ]] || \
    { time bundle exec unicorn --config-file "${local_unicorn_config}"; }
}

wf_fg_stop_bg_unicorn;
wf_fg_set_env_vars;
wf_fg_start_rails;

exit 0;