Automatically Starting ElasticSearch with Rails - ruby-on-rails

I've been doing Ruby on Rails development with ElasticSearch between two machines and its starting to get a little annoying. My usual workflow is:
git pull
bundle install
rake db:migrate (or rake db:setup depending)
rails server
elasticsearch -f -D myconfig.xml
rake environment tire:import CLASS=MyObject FORCE=true
Is there anyway I can add all of these commands to some type of start up script in Rails to bring them all into one place? It would make bringing up a dev environment a lot easier on me everytime I switch machines.

The best way I've found is to use the Foreman gem to kickstart your project and associated processes.

It looks like you should do this in your deployment using Capistrano. Here is an example config/deploy.rb file:
[basic parts omitted]
after "deploy", "bundler:bundle_install"
after "bundler:bundle_install", "db:db_migrate"
after "deploy:db_migrate", "deploy:elastic_search_indexing"
namespace :bundler do
desc 'call bundle install'
task :bundle_install do
run "cd #{deploy_to}/current && bundle install"
end
end
namespace :db do
desc 'fire the db migrations'
task :db_migrate do
run "cd #{deploy_to}/current && bundle exec rake db:migrate RAILS_ENV=\"production\""
end
end
namespace :elasticsearch do
desc 'run elasticsearch indexing via tire'
task :index_classes do
run "cd #{deploy_to}/current && bundle exec rake environment tire:import CLASS=YourObject FORCE=true "
end
end
[rest omitted]
Make sure you have a config file on the target machine (Linux) in /etc/elasticsearch/elasticsearch.yml with contents like:
cluster:
name: elasticsearch_server
network:
host: 66.98.23.12
And the last point to mention is that you should create an initializer config/initializers/tire.rb:
if Rails.env == 'production'
Tire.configure do
url "http://66.98.23.12:9200"
end
end
As you can see, this is the exact same IP address, but only used for the production environment. I assume that you access elasticsearch locally (in development mode) via localhost. elasticsearch is connection per default to
http://0.0.0.0:9200
A good starting point and also in depth help is provided by awesome Ryan Bates and his Railscasts http://railscasts.com/episodes?utf8=%E2%9C%93&search=capistrano

Whats keeping you from putting it in a bash script? And put the script inside your RAILS_APP_HOME/scripts folder?
#!/bin/sh
git pull
bundle install
rake db:migrate
rails server
elasticsearch -f -D myconfig.xml
rake environment tire:import CLASS=MyObject FORCE=true

Related

How can I run a rake task via cron?

I have and rails application and a rake task which I'm going to execute by cron around once in an hour. But the thing is that the task uses rails environment and some classes of my rails application. If I run it as ruby script, I'll have to include all the dependencies it uses and I think it's not possible to do it correctly and in a simple way. So I'll have to run it as a rake task because it'll preserve all the dependencies, right? Then how can I run a rake task from cron?
Note that I prefer not to use any third-party solution when there's no necessity, in this case I don't want to use the gem whenever or the like.
You can add to your crontab something like
0 * * * * /bin/bash -l -c 'cd /path/to/your/project && bundle exec rake foo:bar >> log/cron.log 2>&1'
This will run foo:bar task every hour and write stdout and stderr to log/cron.log.
Please notice bundle exec before rake command.
Using bundler ensure you that task will fetch correct environment.
To specify RAILS_ENV you can do
... && RAILS_ENV=production bundle exec rake foo:bar
Use whenever to simplify your life https://github.com/javan/whenever ;)
Here's an example of a rake task:
task :foo => :environment do
puts "Running rake task in environment: #{Rails.env}"
# can access Models here or whatever
end
Note that the => :environment part is optional, but it what makes your Rails environment to the task block.
You can put rake run_my_task in your cron job.
You may need to use something like cd /home/$USER/my_rails app && rake run_my_task to ensure that the cron runs the task from the Rails root directory.

On Heroku, how can I schedule the postgres database for my Rails app to be periodically reset?

I'm running a small demo site. I'd like to reset the database once an hour or so (automatically, not manually). I could write a rake task to destroy records for each of the models. Is there a simpler approach?
How best to accomplish this?
You can use Heroku Scheduler to schedule a rake task. If you rake task runs with heroku run then it works with scheduler too.
Please refer this link to how to automate rake task on heroku
http://kakimotonline.com/2014/04/27/using-rake-to-automate-heroku-tasks/
Your rake file will look something like this:
namespace :heroku do
def run_command(cmd, app_name)
Bundler.with_clean_env do
sh build_command(cmd, app_name)
end
end
def build_command(cmd, app_name)
"heroku #{cmd} --app #{app_name}"
end
end
Following the example linked by Akshay, I was able to get this working, although not exactly as I planned.
First, a clarification. To add the scheduler add-on on Heroku, you have to provide your credit card number. I'm still getting my bearings with the Heroku platform and am not ready to do that quite yet. So my solution works without the scheduler add-on. Instead it runs as a rake task from your local dev environment and uses the heroku toolbelt to run the reset command on your remote app.
If you are looking to run everything on Heroku, I don't think this will work as you can't run the heroku pg:reset command on Heroku itself. However, it looks like this solution here would work.
Now to my solution.
First, create the following rake file:
# lib/tasks/heroku.rake
namespace :heroku do
# bundle exec rake heroku:reset_db['my-app-name']
# Note: run locally with Heroku toolbelt to reset DB on app
desc 'Reset database with seed data'
task :reset_db, [:app_name] do |t, args|
run_command("pg:reset DATABASE_URL --confirm #{args.app_name}", args.app_name)
run_command("run rake db:migrate", args.app_name)
run_command("run rake db:seed", args.app_name)
end
# Helper Functions
# Source: http://kakimotonline.com/2014/04/27/using-rake-to-automate-heroku-tasks/
def run_command(cmd, app_name)
Bundler.with_clean_env do
sh build_command(cmd, app_name)
end
end
def run_command_with_output(cmd, app_name)
Bundler.with_clean_env do
`#{build_command(cmd, app_name)}`
end.gsub("\n", "")
end
def build_command(cmd, app_name)
"heroku #{cmd} --app #{app_name}"
end
end
Now you can reset your database by running the following rake command from your local environment with your app name (run heroku apps for your app name):
bundle exec rake heroku:reset_db['my-app-name']
And if you want to schedule it to run at regular intervals as I did, add a job to your local crontab (which is a little more complicated than just copying the line above):
# Reset Heroku database hourly
RBENV_SHIM=/home/klenwell/.rbenv/shims/
RBENV_BIN=/home/klenwell/.rbenv/bin
RAILS_APP=/home/klenwell/projects/my-app-name
HEROKU_LOG=/tmp/heroku-cron.log
0 * * * * export PATH=$RBENV_SHIM:$RBENV_BIN:$PATH; eval "$(rbenv init -)"; cd $RAILS_APP && bundle exec rake heroku:reset_db['my-app-name'] >> $HEROKU_LOG 2>&1
For more info on setting up a cron job to run a rake task with rbenv, see this article.
rake db:schema:load accomplishes what you want, though I've never tried running it on Heroku.
You could also try the database_cleaner gem, which is typically used in test environments.
Try heroku run rake db:setup.
But you will have to run it manually anytime you need to.

Delayed Job in Rails 4 with Capistrano

I cant figure how to start Delayed Jobs on a dedicated Ubuntu server.
It works fine on my localhost but when I run on my server
sudo RAILS_ENV=production bin/delayed_job restart
I get
sudo: bin/delayed_job: command not found
On top of that, if I run the "rake jobs:work RAILS_ENV=production" command Im getting the following error:
PG::FeatureNotSupported: ERROR: SELECT FOR UPDATE/SHARE is not allowed in subqueries
Apparently theres an issue with my psql version.
Is there any way I can get the script to work? Any effective Capistrano recipes available? All ive found on the web are old recipes for Rails 3 and older versions of capistrano.
Thanks in advance.
EDIT:
I have already bundled install the daemons gem and generated "delayed_job:active_record" on my local machine, then proceded to cap deploy which bundle installed and migrated in the production server.
The bin/delayed_job file exists in the server yet it fails with command not found.
And add this to config/environment.rb:
ENV['RAILS_ENV'] ||= 'production'
Then at your production server:
RAILS_ENV=production rake db:migrate
RAILS_ENV=test production generate delayed_job:active_record && RAILS_ENV=production rake db:migrate
Now after you do that:
RAILS_ENV=production script/delayed_job start
As for Capistrano error you are facing, please try to add the command like:
run "cd #{current_path}; #{sudo} RACK_ENV=production bundle exec #{current_path}/bin/delayed_job start"
You must run this on target server:
bundle exec rails generate delayed_job

Rails deployment - how do you do rake db:reset with capistrano?

I am using Linode with Ubuntu 10.04 and Capistrano, Unicorn, & Nginx to deploy.
How do I do the equivalent of heroku run rake db:reset with this setup? Is it as simple as cap deploy:cold again to run the migrations?
I've already deployed and want to drop all databases and rerun all the migrations but am not sure which commands to run with this setup to do so.
I wrote a tiny little file you can copy to run arbitrary rake tasks via capistrano: http://jessewolgamott.com/blog/2012/09/10/the-one-where-you-run-rake-commands-with-capistrano/
once setup, you can:
cap sake:invoke task="db:reset"
For Capistrano 3 without actual dropping the database. Use bundle exec cap db:reset
namespace :db do
desc 'Resets DB without create/drop'
task :reset do
on primary :db do
within release_path do
with rails_env: fetch(:stage) do
execute :rake, 'db:schema:load'
execute :rake, 'db:seed'
end
end
end
end
end
You could add the following to your deploy.rb file
namespace :custom do
task :task do
run "cd #{current_path} && bundle exec rake db:reset RAILS_ENV=#{rails_env}"
end
end
Then run cap custom:task to clear the database.
If you are using Capistrano 3, consider using the capistrano-rails-collection.
You can also use copy the code directly from db.rake file from the repository.
Or, if you want a full-fledged solution to run all your rake tasks on a remote server, check out the Cape gem.

How to enter rails console on production via capistrano?

I want to enter the rails console on production server from my local machine via capistrano.
I found some gists, e.g. https://gist.github.com/813291 and when I enter console via
cap production console
I get the following result
192-168-0-100:foldername username $ cap console RAILS_ENV=production
* executing `console'
* executing "cd /var/www/myapp/current && rails console production"
servers: ["www.example.de"]
[www.example.de] executing command
[www.example.de] rvm_path=$HOME/.rvm/ $HOME/.rvm/bin/rvm-shell '1.9.3' -c 'cd /var/www/myapp/current && rails console production'
/var/www/myapp/releases/20120305102218/app/controllers/users_controller.rb:3: warning: already initialized constant VERIFY_PEER
Loading production environment (Rails 3.2.1)
Switch to inspect mode.
and thats it... Now I can enter some text, but nothing happens...
Has anybody an idea how to get that work or another solution for my problem?
I've added my own tasks for this kind of thing:
namespace :rails do
desc "Remote console"
task :console, :roles => :app do
run_interactively "bundle exec rails console #{rails_env}"
end
desc "Remote dbconsole"
task :dbconsole, :roles => :app do
run_interactively "bundle exec rails dbconsole #{rails_env}"
end
end
def run_interactively(command)
server ||= find_servers_for_task(current_task).first
exec %Q(ssh #{user}##{myproductionhost} -t '#{command}')
end
I now say cap rails:console and get a console.
For Capistrano 3 you can add these lines in your config/deploy:
namespace :rails do
desc 'Open a rails console `cap [staging] rails:console [server_index default: 0]`'
task :console do
server = roles(:app)[ARGV[2].to_i]
puts "Opening a console on: #{server.hostname}...."
cmd = "ssh #{server.user}##{server.hostname} -t 'cd #{fetch(:deploy_to)}/current && RAILS_ENV=#{fetch(:rails_env)} bundle exec rails console'"
puts cmd
exec cmd
end
end
To open the first server in the servers list:
cap [staging] rails:console
To open the second server in the servers list:
cap [staging] rails:console 1
Reference: Opening a Rails console with Capistrano 3
exec is needed to replace the current process, otherwise you will not be able to interact with the rails console.
A simple Capistrano 3 solution may be:
namespace :rails do
desc "Run the console on a remote server."
task :console do
on roles(:app) do |h|
execute_interactively "RAILS_ENV=#{fetch(:rails_env)} bundle exec rails console", h.user
end
end
def execute_interactively(command, user)
info "Connecting with #{user}##{host}"
cmd = "ssh #{user}##{host} -p 22 -t 'cd #{fetch(:deploy_to)}/current && #{command}'"
exec cmd
end
end
Then you can call it say, on staging, with: cap staging rails:console. Have fun!
For Capistrano > 3.5 and rbenv. Working in 2021
namespace :rails do
desc "Open the rails console on one of the remote servers"
task :console do |current_task|
on roles(:app) do |server|
server ||= find_servers_for_task(current_task).first
exec %Q[ssh -l #{server.user||fetch(:user)} #{server.hostname} -p #{server.port || 22} -t 'export PATH="$HOME/.rbenv/bin:$PATH"; eval "$(rbenv init -)"; cd #{release_path}; bin/rails console -e production']
end
end
end
I have fiddled with that approach as well, but then resorted to avoiding building my own interactive SSH shell client and just went with this snippet I found that simply uses good old SSH. This might not be suitable if you have some weird SSH gateway proxying going on, but for logging into a box and performing some operations, it works like a charm.
In my experience, capistrano isn't built to work very well with interactive terminals.
If you have to execute things in multiple terminals, I'd suggest iterm, which has a "send to all windows" function that works very well for me:
http://www.iterm2.com/#/section/home
I have a somewhat difficult environment, which is influx ... So bash -lc isn't really an option right now. My solution is similar to #Rocco, but it's a bit more refined.
# run a command in the `current` directory of `deploy_to`
def run_interactively(command)
# select a random server to run on
server = find_servers_for_task(current_task).sample
# cobble together a shell environment
app_env = fetch("default_environment", {}).map{|k,v| "#{k}=\"#{v}\""}.join(' ')
# Import the default environment, cd to the currently deployed app, run the command
command = %Q(ssh -tt -i #{ssh_options[:keys]} #{user}##{server} "env #{app_env} bash -c 'cd #{deploy_to}/current; #{command}'")
puts command
exec command
end
namespace :rails do
desc "rails console on a sidekiq worker"
task :console, role: :sidekiq_normal do
run_interactively "bundle exec rails console #{rails_env}"
end
end
For a Rails console in Capistrano 3 see this gist: https://gist.github.com/joost/9343156
I have just used capistrano-rails-console gem to open rails console and it is working fine.

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