Working with timezones in rails

coderhs — Thu, 11 Aug 2016 07:32:15 +0000

Ruby on Rails being an amazing framework, helps us manage the timezone of our rails application. It gives us access to a lot of helpers, to make our life easier. For example, if you want to change all the date and time of your application to the logged in users time zone, we just have to place the following code in the application_controller.

# app/controllers/application_controller.rb
around_action :set_time_zone, if: :current_user
private
def set_time_zone(&block)
  Time.use_zone(current_user.time_zone)
end

We assume that you have stored the user’s time_zone in your database in the time_zone column. The application to show timezone can be set in your application.rb, if we don’t set a particular timezone then the application will just show the systems timezone.

config.time_zone = 'Central Time (US & Canada)'

If you want to know all the timezone options available in rails, run the rake -D time command in your terminal. Even though rails would take care of the timezone, when we are using certain ruby commands, it gives us our systems timezone and not the one set by rails. So to avoid surprises, we should be aware of the timezones we are exposed to. A rails app, would always be exposed to three timezones:

System timezone
Database timezone
Rails applications own timezone

All three could be different, for example your system timezone could be in IST, database in UTC, and rails app running in PDT. To avoid accidental assessment to a different timezone, always keep in mind the commands you should and should not use. DO NOT USE – as they all give you time with respect to the system time

  * Time.now
  * Date.today
  * Date.today.to_time
  * Time.parse("2015-07-04 17:05:37")
  * Time.strptime(string, "%Y-%m-%dT%H:%M:%S%z")

USE – these give you access to the rails application time (which we can change with respect to the user)

* Time.current
* 2.hours.ago
* Time.zone.today
* Date.current
* 1.day.from_now
* Time.zone.parse("2015-07-04 17:05:37")
* Time.strptime(string, "%Y-%m-%dT%H:%M:%S%z").in_time_zone

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Enable log rotation within the rails application

coderhs — Wed, 27 Jul 2016 05:00:19 +0000

heroku, as heroku won’t let you store files for more than 15 minutes in their server. You also do not need it if you are using some third party services like loggly or papertrail to manage your logs . In the unix world, you can use log rotate service, which would be installed by default in all linux servers. But we at Red Panthers feel that everything that touches or involves our rails application should be placed along with our rails application as much as possible. If you feel the same way, it can be achieved by placing the code below in the production.rb file.

config.logger = Logger.new( Rails.root.join("log", Rails.env + ".log" ), 5 , 100 * 1024 * 1024 )

The Logger.new accepts three parameters:

The file name, which would be production.log
The number of files you want to keep
The size of each file in bytes. (100 * 1024*1024 means 100 MB)

So, when the time comes to add the 6th 100 MB log file, it will delete the oldest. Unix Way For those who still want to use the unix log rotate, they should create a new config file at /etc/logrotate.d/myrailsapp-config as shown below

$ cat /etc/logrotate.d/myrailsapp-config
/var/www/myrailsapp/current/log/*.log {
  compress
  copytruncate
  daily
  dateext
  delaycompress
  missingok
  rotate 90
}

In case you were wondering, here are what these options mean:

compress – Compress logs using gzip
copytruncate – Copy the log out of the way, and then truncate the existing logs
daily – Rotate daily
dateext – Add the date the logs were rotated as the extension instead of a number
delaycompress – Skip compressing the log until the following day
missingok – Do not raise an error when there is a missing log file
rotate 90 – Keep up to 90 days worth of logs

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management – redpanthers.co

Working with timezones in rails

Enable log rotation within the rails application