Rails whenever not able to execute service methods - ruby-on-rails

I have a NotificationService which has methods like this:
def trial teacher
notification = Notification.create(recipient: teacher, tag: 'trial', text: 'text', title: 'title')
notification.deliver
end
I want to have a Whenever runner job to execute this method ... bin/rails runner "NotificationService.new.trial" --silent, but if I try to do so I get an error Please specify a valid ruby command or the path of a script to run.. Yet if I try to use a model, not a service, it works (for instance, Notification.last.deliver)
And also that executes perfectly fine on development, but doesn't work on production. Seems like that service class doesn't exist for Cron
What am I missing?

Solved it! Turned out that the trouble was not with Whenever or Cron, but the exact method I was trying to run.
And as it was production environment with constantly changing data, when I ran NotificationService.new.trial I just got lucky not to get an error. Then data changed and Cron's attempts to run were failing.
Using safe navigation operator (&.) solved everything!

Related

Install generator won't see a method I defined

I'm trying to use my Engine in another app to test the install generator and it seems to be failing. I haven't used my install generator for a long time, so I'm not sure when it broke (or if it ever truly smoothly worked). My project is based off radar/forem, so I tried to borrow a lot of their code (including the generator).
Edit: My installer works for the engines test/dummy but not in other apps. Why?
GH issue: https://github.com/NJayDevelopment/mongoid_forums/issues/16
Here is the log:
$ rails g mongoid_forums:install
What is your user class called? [User]
What is the current_user helper called in your app? [current_user]
Defining mongoid_forums_user method inside ApplicationController...
insert app/controllers/application_controller.rb
Adding mongoid_forums initializer (config/initializers/mongoid_forums.rb)...
create config/initializers/mongoid_forums.rb
(erb):5:in `template': undefined method `per_page' for MongoidForums:Module (NoMethodError)
The route is successfully added, however the initializer/mongoid_forums.rb is a blank file. The method is defined exactly how radar/forem does it, what could be the error?
Here is the relevant code:
Per page method definition: https://github.com/NJayDevelopment/mongoid_forums/blob/master/lib/mongoid_forums.rb#L33
Mattr accessor:
https://github.com/NJayDevelopment/mongoid_forums/blob/master/lib/mongoid_forums.rb#L9
Initializer template:
https://github.com/NJayDevelopment/mongoid_forums/blob/master/lib/generators/mongoid_forums/install/templates/initializer.rb
Install generator at error point:
https://github.com/NJayDevelopment/mongoid_forums/blob/master/lib/generators/mongoid_forums/install_generator.rb#L47
Turns out when you try requiring mongoid_forums in pry, you'll see that an error involving decorators occurs. The issue is fixed here in my pull request to decorators: parndt/decorators#13
It's because of the way files are required and how load! is called over there.
Waiting on PR status, that is the same version that radar/forem uses as well.

Why is Rails runner not returning a result?

I am having problems with the Rails runner. When I try to use if, even by command line, it does nothing! it doesn't show error messages, nor results from actions.
For example, if I try
rails runner Credit.count
having defined the model Credit, and the method count as
Credit.first.update_attribute(:estado, "En proceso")
or even simpler tasks, the runner does nothing!
I've tried saying that the environment is development, but nothing works. Does anyone has any insights? Am I doing something wrong?
Edit: I am watching the database, that's the problem, there is no update. I changed the value of the column "estado" for the first element to something other than "En proceso", however, no matter how many times I use the runner, the db doesn't show any change at all.
rails runner: runner runs Ruby code in the context of Rails non-interactively
update_attribute : it only return true or false, if you want to output the result, you can use "puts" or "p".
For example,
$ rails r "User.first" #no output, even it will return a user object
$ rails r "puts User.first" # you can use "puts" get the output
#<User:0x007f8a2c76e608>
if you just written Credit.first.update_attribute(:estado, "En proceso") in console, you shouldn't have results, but you could see result in DB, for checking if update_attribute really update it you could write as update_attribute! also you could just write:
p Credit.first.update_attribute(:estado, "En proceso") which should print true or false to console
Turns out I am an idiot.
First, I had to change the name of the method, calling Credit.count calls the default count method, so I changed it to myMethod.
After that, I was able to use puts function and update the database easily :)

Permanent daemon for quering a web resource

I have a rails 3 application and looked around in the internet for daemons but didnt found the right for me..
I want a daemon which fetches data permanently (exchange courses) from a web resource and saves it to the database..
like:
while true
Model.update_attribte(:course, http::get.new("asdasd").response)
end
I've only seen cron like jobs, but they only run after a specific time... I want it permanently, depending on how long it takes to end the query...
Do you understand what i mean?
The gem light-daemon I wrote should work very well in your case.
http://rubygems.org/gems/light-daemon
You can write your code in a class which has a perform method, use a queue system like this and at application startup enqueue the job with Resque.enqueue(Updater).
Obviously the job won't end until the application is stopped, personally I don't like that, but if this is the requirement.
For this reason if you need to execute other tasks you should configure more than one worker process and optionally more than one queue.
If you can edit your requirements and find a trigger for the update mechanism the same approach still works, you only have to remove the while true loop
Sample class needed:
Class Updater
#queue = :endless_queue
def self.perform
while true
Model.update_attribute(:course, http::get.new("asdasd").response)
end
end
end
Finaly i found a cool solution for my problem:
I use the god gem -> http://god.rubyforge.org/
with a bash script (link) for starting / stopping a simple rake task (with an infinite loop in it).
Now it works fine and i have even some monitoring with god running that ensures that the rake task runs ok.

Ruby on rails, run a method on server start 2.3

I want to run a method, on the startup of the rails server. It's a model method.
I tried using config/initializers/myfile.rb, but the method was invoked during migrations, so it SELECTed from a nonexistant table.
Tried environment.rb also, but the class does not exist yet (and will probably have the same problem with migrations)
I don't know where to put that method, so it'll run only on server startup and not during migrations.
There are some things you could do to actually improve this a bit. The issue is that you are running this code when rake loads your environment, but you really only want to run this when the environment is loaded by an instance of your web server. One way to get around this is to set a value when rake loads your environment, and when that value is set, to not execute your initializer code. You can do this as follows:
task :environment => :disable_initializer
task :disable_initializer do
ENV['DISABLE_INITIALIZER_FROM_RAKE'] = 'true'
end
#In your initializer:
ENV['DISABLE_INITIALIZER_FROM_RAKE'] || MyModel.method_call
There is no way to avoid this from my understanding. You can put the initializer code that relies on the new table in a rescue block to quiet things down so others can run migrations.
Try putting your method call in boot.rb, in the run method after the Rails::initializer call. I don't have rails in front of me right now because I'm at work but I think that the whole environment should be loaded by that point and you can run methods on the framework.
I found this to work quite well:
if File.basename($0) == "rails" && ARGV == []
It also detects "rails generate .."

delayed_job - Performs not up to date code?

I'm using delayed_job (tried both tobi's and collective_idea's) on site5.com shared hosting, with passenger as rails environment.
I managed to make jobs done.
However, it seems the plugin ignores any changes in a job class source code after first run.
I have restarted the server on every change (touch tmp/restart.txt) but it still ignores it.
Example:
file: lib/xx_job.rb
class XxJob
def perform
Rails.logger.info "XX START"
TempTest.delete_all
i = 0
10.times {
i+=1
TempTest.create(:name => "XXX")
sleep(1)
}
Rails.logger.info "XX END"
end
end
In a simple controller I call:
Delayed::Job.enqueue(XxJob.new)
Conclusions I have gathered:
If I change xx_job.rb to xx_job1.rb - error on the controller
If I change class XxJob to class XxJob1 - error on the controller
If I delete all the perform method content - the old code old code is executed
New .rb file with class and perform, enqueue this class - works perfectly
If I change something in that new file's perform and run job again - old code is executed
Between every change I made a restart for the server.
It seems like Passenger or something else saves class cache.
How can I delete this cache? Is is stored on the server somewhere? (I hope I have access to it from the shared hosting)
Thanks!
If you run delayed job workers daemonized, then you need to restart them to reload the code. Also, keep in mind that each worker loads its own instance of rails.
Eventually I figured that out - several workers were running in background, each of them caught a job and had their own cache.
I didn't know how to kill them so I changed the table's name for several seconds. That killed them :)
Then I used https://github.com/tobi/delayed_job/wiki/Running-Delayed::Worker-as-a-daemon as worker start, and it works great.

Resources