So one of the challenges I faced moving to the FreeBSD was that for the services I wanted have, I had to come up with a kill script for shutting down or restarting them.

The challenge is especially hard, since the PID of the Elixir applications multiplies. And you have to kill them by hand. And because of fault-tolerant nature of Elixir, it kind of feels like killing a hydra:

Cut off one head, two more shall take its place.

So what can one do? Just create a release, and the executable contains start stop restart and a bunch of more useful commands¹.

So build it like this:

mix release

and for example if the application name is blog and it is made using phoenix, you can do this:

PHX_SERVER='1' MIX_ENV='prod' _build/prod/rel/blog/bin/blog start  

for a service on FreeBSD I settled on this script for my blog:

#!/bin/sh
#
# PROVIDE: blog
# REQUIRE: daemon
# BEFORE:
# KEYWORD: shutdown
#

. /etc/rc.subr

name="blog"
desc="blog - imadethissite.com"
rcvar="blog_enable"

project_dir="/home/prma/blog"

mix_exec="/usr/local/bin/mix"
daemon_exec="/usr/sbin/daemon"

mix_opts="phx.server"
secret_key_base="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"

pid_file="/var/run/${name}.pid"
daemon_user="[your_user_name]"

server_port=4001
log_file="/var/log/${name}.log"

load_rc_config "$name" :"${blog_enable="NO"}"

start_cmd="blog_start"
stop_cmd="blog_stop"
compiled_path="_build/prod/rel/blog/bin/blog"

PATH=$PATH:/usr/local/lib/erlang27/bin/erl

blog_start() {

  cd ${project_dir} || exit
  echo "[BLOG] Starting BLOG at: http://localhost:${server_port}"
  su - ${daemon_user}  -c "cd ${project_dir}  && PORT=${server_port} PHX_SERVER='1' MIX_ENV='prod' SECRET_KEY_BASE=${secret_key_base} $compiled_path start" >"${log_file}" 2>&1 &
  echo "[BLOG] started!"
}

blog_stop() {
  cd ${project_dir} || exit

  echo "[BLOG] Stopping BLOG"
  $compiled_path stop
  echo "[BLOG] Stopped"
}

run_rc_command "$1"