如何使用capistrano在远程计算机上启动play2应用程序

Question

I'm trying to deploy a play2 application with capistrano, but I can't figure out how to (re)start the play2 application after a successful deployment. Just triggering 'play start' will cause the process to be hanging waiting for me to press ctrl+D

I've created a start script in the play app root folder

#!/bin/bash

nohup bash -c "/var/lib/play2/play start &>> /tmp/myapp.log 2>&1" &> /dev/null &

It works great when I run this on the server. When I try to call this from my local machine over ssh it also works. But when I am using capistrano, it doesn't seem to do anything. My capistrano config looks like this:

namespace :deploy do

  task :restart do
    stop
    sleep 1
    start
  end

  task :start do
    run "cd #{current_release}/trip-api && ./start.sh"
  end

  task :stop do
    run "cd #{current_release}/trip-api && ./stop.sh"
  end
end

What's the best way to start a play2 application on a remote machine? How to get it working with capistrano?

Answer 1

Have a look at play documentation on deploying your application on production

The recommended way is to package your app with

play clean compile stage

And then run it with

$ target/start

To stop it, have a look at the docs:

The server's process id is displayed at bootstrap and written to the RUNNING_PID file. To kill a running Play server, it is enough to send a SIGTERM to the process to properly shutdown the application.

In this quickstart for Openshift , it shows another way to start play as a service and how to stop it .

basically you do something like this to start:

APP_COMMAND="${OPENSHIFT_REPO_DIR}target/start $PLAY_PARAMS "\
"-Dhttp.port=${OPENSHIFT_INTERNAL_PORT} "\
"-Dhttp.address=${OPENSHIFT_INTERNAL_IP} "\
"-Dconfig.resource=openshift.conf"

echo $APP_COMMAND &>> $LOG_FILE
nohup bash -c "${APP_COMMAND} &>> ${LOG_FILE} 2>&1" &> /dev/null &

and to stop it

pid=`cat RUNNING_PID`
echo "Stopping play application" >> $LOG_FILE
kill -SIGTERM $pid

Answer 2

There are few fresh topics about running application available at Google Groups:

• Start an application as a background process
• When deployed on Ubuntu 10.04 cant detach from console

It's good idea to follow or join them

Answer 3

I would suggest using runit. We are currently running a bunch of services in production and it works great.

It only involves creating a simple shell script named run, pointing runit to its containing directory and then start it. Services should not daemonize by themselves and runit controls pid files, etc.

There is a command ( sv ) to start, stop and query services. ( sv start|stop|status|restart yourapp ).

A cursory google search got me this http://rubygems.org/gems/capistrano-runit though I do not use capistrano at all so I can't vouch for it's usefulness.

http://smarden.org/runit/

The faq is the best place to start: http://smarden.org/runit/faq.html

In debian you just apt-get install runit and are good to go. update-service --add /your/service/dir/ will register the service with runit.

On deployment we stop services, change binaries and start services; it is really simple.