How to execute a command on the server with Capistrano? - ruby-on-rails

I have a very simple task called update_feeds:
desc "Update feeds"
task :update_feeds do
run "cd #{release_path}"
run "script/console production"
run "FeedEntry.update_all"
end
Whenever I try to run this task, I get the following message:
[out :: mysite.com] sh: script/console: No such file or directory
I figured it's because I am not in the right directory, but trying
run "cd ~/user/mysite.com/current"
instead of
run "cd #{release_path}"
Also fails. Running the exact same commands manually (through ssh) works perfectly.
Why can't capistrano properly cd (change directory) into the site directory to run the command?
Thanks!
Update: Picked an answer, and thank you so much to all who replied.
The best answer may actually be the one on server fault, though the gist of both (the one on server fault and the one on stack overflow) is the same.

You want to use script/runner. It starts an instance of the app to execute the method you want to call. Its slow though as it has to load all of your rails app.
~/user/mysite.com/current/script/runner -e production FeedEntry.update_all 2>&1
You can run that from the capistrano task.

I cannot imagine that you would be able to remotely log into rails console from capistrano. I suggest you call your model method from a rake task.
How do I run a rake task from Capistrano?
As for the latter part of your question, are you logging into the server with the same user account as capistrano?

Related

Trouble with crontab and using whenever gem

Hi I am using the whenever gem and trying to send a daily email. For testing I set it to 2 minutes, and I have it in my schedule.rb file. It calls a task I have in a rake file. When I run bundle exec rake task_to_be_called, it runs and works. But the actual scheduling does not work. When I try to run things to find out crontab it says no such file or directory. Is there some way to get a crontab file, or do I make it? How do I test or get my scheduler to run that task?
EDIT: Thanks for the advice on sharing code and error.
In my lib/tasks/daily_email.rake I have
desc 'Daily email rake task test'
task daily_email_call: :environment do
ReportMailer.with(email: "email#email.com").daily_summary_report.deliver_now
end
Then in my config/schedule.rb I have
every 2.minute do
rake 'daily_email_call'
end
When I run bundle exec rake daily_email_call it functions correctly and does the send email task. My question is how to get it to do it on the schedule. I have no crontab file. Am I even able to do this locally or would it need to be on a running server. I am using windows not Linux when I run mine locally.
There is a typo in the file name,
lib/tasks/darily_email.rake => lib/tasks/daily_email.rake
I guess this is causing the error, no such file or directory

Google App Engine: Ruby on Rails - Execute migrations automatically

I was wondering if it was possible to run migrations automatically during deployment with Google App Engine. I have been using AWS Elasticbeanstalk for a while and they were ran automatically but now I am considering moving to the Google App Engine for my future projects.
Right now, I must run this command manually:
bundle exec rake appengine:exec -- bundle exec rake db:migrate GAE_CONFIG=app.yml
Thank you
WARNING: As discussed in comments, there is a race condition in migrations if deployment is done on multiple containers in parallel, because it will try to run migration on all containers. Solution is being discussed in comments, i will update this answer when we land on something.
Disclaimer: This answer is not exactly what was asked for, but it solves same problem and it works. And from what i can tell from question, doing it with some appengine config is not a requirement, rather he just want the migrations to run automatically.
I will expand on my comment on question, here is something i tried and it works. I am strong believer of KISS(keep it simple and stupid). So instead of trying to figure out appengine(which i have never used anyway) if i were you, i would take a generic approach. Which is, to plug into rails server booting process and trigger migrations. For this we have multiple approaches.
With my understanding of appengine and suggested by this official doc link appengine has a app.yaml file, this file has an entry something like:
entrypoint: rails server
So we will use this entry point to plug in our code to run migrations before starting server. For this i did this:
Make a new file in bin directory, i named it
rails_with_migrations.sh you can name it whatever you like.
Give it execute permissions with chmod +x bin/rails_with_migrations.sh
Put this code inside it:
#!/bin/bash
bundle exec rake db:migrate
bundle exec rails $#
Of course you can give whatever RAILS_ENV you want to give these.
Now in app.yaml on the entrypoint section, instead of rails server give it bin/rails_with_migrations.sh server and it should be it. It worked on local, should work everywhere.
NOTE: In entrypoint: i have bin/rails_with_migrations.sh server here, server is rails command parameter, you can pass as much parameters as you like these all will be passed to rails server command with $#'s magic. It is there to allow you to pass port and any other parameters you may need to provide for your environment. Also it allows you to run rails console locally with bin/rails_with_migrations.sh console which will also cause migrations to get triggered.
UPDATE1: As per comment, i checked what happens if migration fails, and it starts server even if migration fail. We can alter this behavior of-course in our sh file.
UPDATE2: The shell-script with migration error code handling will look something like:
#!/bin/bash
bundle exec rake db:migrate
if [ $? -eq 0 ]
then
bundle exec rails $#
else
echo "Failure: migrations failed, please check application logs for more details." >&2
exit 1
fi
This update will prevent server from starting and causing a non zero exit code from the script, which should indicate that this command failed.

Engineyard Deployment: How to detect in deployhooks that its the first attempt to execute 'rake db:seed'

I am having trouble to detect that this is the first attempt of deployment after a server instance is booted. I need to run the command rake db:seed only the first time to set the default users and other details in database. I have no idea if this is possible.
can anybody help me please
The best way to find out is by sending --extra-deploy-hook-options while running deployment command and check in the after_migrate.rb if config[:initial] is present or not. The command would look like
ey deploy -e myapp_staging --config=initial:true
after_migrate.rb hook will looks like:
on_app_servers do
if config[:initial] == 'true'
$stderr.puts "Seeding the data"
run "cd #{config.release_path}"
run "bundle exec rake db:seed"
else
$stderr.puts "Skipping the Seeding process"
end
end
For more information ey help deploy
There are a few ways you can do this.
The most simple one would be to do this in db/seeds.rb and query if data already exists that would otherwise be overwritten when running.
If that is done you can run rake db:seed in a deploy hook.
You can find documentation on deploy hooks here: https://support.cloud.engineyard.com/hc/en-us/articles/205407008-Use-Ruby-Deploy-Hooks

Scheduling rake task with cron

I'm trying to set daily cron job to update my site stats, but it looks like it doesn't work.
Cron entry (for deployer user):
0 0 * * * cd /var/www/my_site/current && rake RAILS_ENV=production stats:update
I'm running ubuntu server, with rbenv.
Any idea what's wrong?
Many times $PATH is defined differently when cron runs compared to when you are working in your own shell. Do "whereis rake" to find the full path to rake and then replace "rake" with its full path. (I am assuming that the "cd" command is working, so I am focusing on whether "rake" is found / running properly.)
Has cron sent you any emails with error messages after you added your command to your crontab?
You might want to run "crontab -l" under the proper user account to make sure that your cron command is actually registered within the crontab, especially if you aren't receiving any emails.
The presence of a Gemfile can also affect the ability to properly run rake. See, for example, Error: "Could not find rake", yet Rake is installed

How to autostart Rails delayed jobs?

I'm using delayed job to create job queues such as 'mailer'
For this to work I have to run this:
$ RAILS_ENV=development QUEUE=mailer rake jobs:work
But if the server crashes and is restarted, I need the worker to start running again automatically.
What would be the recommended way to deal with this?
You need to use a third-party service like monit/bluepill/god/upstart to watch the process and restart it. I recommend using the combination of foreman and upstart. See here: http://blog.daviddollar.org/2011/05/06/introducing-foreman.html
Some time ago I wrote a patch for the DelayedJob to reload the classes for every job in development mode. Same patch should work for your requirement also.
betamatt's approach is definitely one way to do it if you have such a monitoring tool in place.
Another way to do it would simply be to add a script to your OS's startup which runs the RAILS_ENV=development QUEUE=mailer rake jobs:work command under a user who has the necessary permissions.
Here's an example of how to do it on Ubuntu using Upstart, but if you lookup similar init.d methods, or whatever is the relevant for your server OS, you'll find other ways. What you're looking for, basically, is "How to run a script on startup [your OS name]", and then wrap your command in an executable script.
I had the same issue with my application am working with. So i wrote a rake task which runs every minute(as a cron job). When delayed job starts it will create a .pid file in the temp folder. I used this to check the existence of a delayed job process. If the file doesn't exist i ran the console command through code.
delayed_job_status = File.file?("./tmp/pids/delayed_job.pid")
This will check the existence of process. If nil response go to next statement
./bundle exec script/delayed_job start production
This will start delayed job
My solution was creating the bash script in user's home "delayed_job_startup.sh"
which contain
#!/bin/bash
cd /home/deploy/project/current/
RAILS_ENV=production bin/delayed_job start
and in file /etc/rc.local I run this script from my user
su -s /bin/bash - deploy /home/deploy/delayed_job_startup.sh

Resources