I'm trying to create a migration for my app, and in this app I'm using a gem that tries to startup a different service upon app startup. Apparently, creating a migration...
rails generate migration AddSomeStuffToTable stuff:string
...activates the app, and this gem which tries to connect to startup the service. It appears that starting up the app via generating a migration makes the service startup unable to connect, so it just keeps sleeping and trying again, never actually running the migration.
In this gem, I've already dealt with this for rake, so this is what I've got so far:
MyService.start unless defined? Rake or defined? IRB
This handles the rake problem (like rake db:migrate, rake db:populate), but how can I handle the creation of migration, which (as far as I know) is not a Rake task?
You could try using environment variables for disabling the service:
MyService.start unless ENV['NO_SERVICE']
And run your command like this:
NO_SERVICE=1 rails generate migration AddSomeStuffToTable stuff:string
However, I doubt this scales well, especially if multiple developers are in the app. A better approach might be to do the reverse of this, to only start the service if a particular env variable is present. However, going this direction, you'd need to make sure your app servers set this variable, for example:
Apache: SetEnv START_SERVICE 1
nginx: env START_SERVICE=1
thin: START_SERVICE=1 thin start
Related
I need to parameterize some of my cron tasks that I'm generating with whenever by values that I usually access with the rails config gem. So I want to do something like:
every 2.hours do
execute 'my/command/with/parameter #{Settings.parameter}'
end
When I try to do this I get:
config/schedule.rb:14:in `initialize': uninitialized constant Whenever::JobList::Settings (NameError)
So I conclude that whenever doesn't run in the Rails environment, which is a shame as I'd like to do some cooler stuff with it (schedule stuff based on the DB state after running rake db:seed, for example). Is there any way to get the whenever to run in the Rails context?
Rails comes with "runner" which allows a non-web-stack script to have access to the Rails app's environment and configuration. It's tailor made for this sort of task.
I am a beginner.I am trying to launch rails server using the command.But I am getting an error. I tried searching in the google but no results.I will attach a picture of the log I got when I executed that command.
What Mysql error are you getting?
And what is in your config/database.yml?
So far, you have created the folder structure for a Rails app (rails new), then installed all the relevant components (bundle install).
When you start the server (rails server) it starts in "development" mode (you also have "test" mode for unit tests and "production" mode for when your app is live - and each has slightly different options). One of the first things the Rails server tries to do is connect to the database, so it looks in config/database.yml for the database specified in the development section.
So probably, it's trying to connect to a database that doesn't exist yet, with a username and password that are wrong.
First thing to do is to update the username and password in config/database.yml to match your local Mysql server.
Second thing to do is to build the development database; the command for that is "bin/rake db:create" (or "bundle exec rake db:create" if you're on Rails 3.x).
Hopefully that should be enough to get your server started.
How did you setup your rails app?
It seems like maybe you didn't type
bundle install
This command downloads and updates all of your gems. Action View is a rails dependency.
I have successfully managed to set up a VPS production server (Ubuntu 10.04 LTS) from the excellent Railscasts episode. It's an "internal" server (not live yet), so I've been building my app locally and doing a cap deploy at regular intervals to check that things are running smoothly.
However, what I'd like to do now is delete all records on the production server (as I've just been testing stuff) - that is, to start with a completely empty database for when the site actually goes live to the public.
Obviously, I can do this locally by running something like rake db:reset, but how do I do this on the production server? Should I be adding some code to my deploy.rb file?
I'm a bit of a noob at this, but I've been unable to find anything via a Google search.
** EDIT ** Oh, and obviously this is a one-off - once things go live, I'll remove any code which deletes records!
You can ssh into the server and run any rake command from the application directory. You could create a Capistrano task just to run this one rake task, but since this task is obscenely dangerous with any real system I would not recommend it. The last thing you would want is to accidentally run it.
I'm creating an app that must allow the non-programmer end user to install the application by himself.
I already handled the ruby env + web server + database installation part. Now I have to be able to setup the database for the app. I'm thinking about running rake db:setup inside a InstallationController (which will be only accessible during the installation process).
Is it possible? How can I do that?
I'm planning to use Warble and JRuby, so I won't be able to do it by using the command-line inside my app.
As long as the database exists (or creates on use like sqlite3) you can throw an initializer in your app to run the migrations pretty easily.
ActiveRecord::Migrator.migrate(Rails.root.join('db','migrate'))
You won't be able to use the controller if the database is not properly set. If the setup has to be through a web interface you can include a small Sinatra application that takes care of the DB creation, migrations, etc. To do it you only have to shell out your commands (you can do it by backquoting the command):
puts "Migrating database..."
`rake db:migrate`
I would like my development environment for Rails to automatically start redis and resque (and potentially in other projects, mongod, mysql-server etc.) for me, in the following cases:
When starting up the development server rails server.
Additionally, it would be nice if the following cases detect already running services, and, if not running start them up too:
Rake rspec, rspec /spec, when running tests.
When starting up a rails console.
When shutting down the rails server, the started child-services should be shut down too.
What is the correct place for such additional startup scripts?
And how to avoid them being started in production too (where I run everything trough /etc/init.d services)?
A lot of these built-in tasks are available as rake tasks already.
You can create a master rake task that does it all.
For example, with resque, you get "rake resque:start" "rake resque:scheduler:start", etc.
You can create a generic "start" task that depends on the rest. Similarly, a "stop" task would shut everything down.
So you would do:
rake start # starts all associated processes
rake stop # stops them all
This is also very use to use from Capistrano, when you end up deploying your code somewhere else. Rake tasks are very easy to call from Capistrano.
I think it's really better to do that in some external script. Do it in your rails server command can be really annoying to anyone to try your code.
By example, in one year, a nez developper come to your project. He can be desoriented if your rails server commande launch a such of other application in background.
In same idea, if you do that you need maintain your code in your rails env. Can be a little tricky. Maintain an independant script can be more usefull.
You can add your script in script directory. That be a good pratice. But not when you launch a command with a manual who do not that.