Rails | Apartment gem | Resets AR objects when tenant switched

I ran into a weird situation today. Active Record objects stored in vars are removed when I switched from one tenant to another on the fly. This will create a weird test-failing scenario and you never know why its happening.

def switch(name)
  yield(name)
end

@customers = [1,2,3]
switch('shiva') do |name|
  puts name
  puts @customers
end

# Gives output
# shiva
# 1
# 2
# 3

 

but when I do this

@roles     = Role.all
@customers = org.branches
@list      = [1, 2]

puts 'Role count' + @roles.count.to_s
puts 'Customer count' + @customers.count.to_s
puts 'list count' + @list.count.to_s

Apartment::Tenant.switch!(org.database_name)
puts '-------'
puts 'Role count' + @roles.count.to_s
puts 'Customer count' + @customers.count.to_s
puts 'list count' + @list.count.to_s

output is

Role count2
Customer count2
list count2
-------
Role count0
Customer count0
list count2

 

Reason

# apartment-2.2.0/lib/apartment/adapters/abstract_adapter.rb
#   Switch to a new tenant
#
#   @param {String} tenant name
#
def switch!(tenant = nil)
  run_callbacks :switch do
    return reset if tenant.nil?

    connect_to_new(tenant).tap do
      Apartment.connection.clear_query_cache
    end
  end
end

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Rails : PaperTrail gem : Custom events to track fields changed

In my project, I was asked to keep track of changes in records. I found PaperTrails gem, and its found to be pretty useful.

But it lacks a straightforward feature to know the fields changed in that particular version. Then I thought to write custom event name so that I could grep the field_name I wish to check.

# == Schema Information
#
# Table name: tasks
#
#  id                :integer          not null, primary key
#  worker_id         :integer
#  customer_id       :integer
#  kind              :integer          default(0)
#  status            :integer          default(0)
#  note              :text
#  start_on          :datetime
#  complete_on       :datetime
#  started_on        :datetime
#  completed_on      :datetime
#  created_at        :datetime         not null
#  updated_at        :datetime         not null
#  driver_acceptance :integer          default(0)
#  refuel_id         :integer
#  shift_id          :integer
#

class Task < ActiveRecord::Base
  include Timeable
  has_paper_trail
  
  # Update event-name on update
  before_save :paper_trail_events, on: :update

  enum status: { scheduled: 0, started: 1, skipped: 2, completed: 3, paused: 4, rescheduled: 5 }
  enum kind: { inter_location: 0, refuel: 1, break: 2 }
  enum driver_acceptance: { pending: 0, accepted: 1, rejected: 2, sent: 3 }

  private

    def paper_trail_events
      changed_fields         = self.changes.keys - ['created_at', 'updated_at']
      self.paper_trail_event = "Updated #{changed_fields.join(',')}"
    end
end

In Rails Console

> Task.find(1768).versions.map &:event
=> ["Updated start_on,complete_on,status", "Updated worker_id"]

 

Invalid CSS after “(min-width: “: expected expression (e.g.

Two possible reasons:

• You might be @importing minified version of css assets like bootstrap.min.css
  • I did same and later solved using normal version css file
• Search the suspect file if it has the content (min-width: and (max-width on the same line
  • see if there is any variable used
  • there might be px unit missing after the var
  • see if there is any possibility of var being nil
  • use @if condition to solve problem
  • eg:

@if  $min != null and $max != null{
  @media (min-width: $min + 'px') and (max-width: $max + 'px') {
    @content;
  }
}

Ruby on Rails | Setup MS-SQL server in Ubuntu 17.04

MSSQL Server Installation

Follow these instructions https://www.rootusers.com/how-to-install-microsoft-sql-server-on-ubuntu-linux/

Note: During installation it will ask you for password, put a strong password remember it or note it down.

Reset Server Admin(SA) password

If you, unfortunately, forgot the SA password then you can reset follow the commands

$ sudo systemctl stop mssql-server
$ sudo /opt/mssql/bin/mssql-conf setup

Testing

If you wish to test if Server is installed and ready to receive requests

sqlcmd -S localhost -U sa -P your_strong_password

Install FreeTDS binaries

$ apt-get wget
$ apt-get install build-essential
$ apt-get install libc6-dev

$ wget ftp://ftp.freetds.org/pub/freetds/stable/freetds-1.00.21.tar.gz
$ tar -xzf freetds-1.00.21.tar.gz
$ cd freetds-1.00.21
$ ./configure --prefix=/usr/local --with-tdsver=7.3
$ make
$ make install

Install required gems

# SQL Server (2012 or higher required)
#
# Install the adapters and driver
#   gem install tiny_tds
#   gem install activerecord-sqlserver-adapter
#
# Ensure the activerecord adapter and db driver gems are defined in your Gemfile
#   gem 'tiny_tds'
#   gem 'activerecord-sqlserver-adapter'

If still, you cannot install the gem tiny_tds then try using sudo
$ sudo gem install tiny_tds -v '2.0.0'

Importing from Remote to Localhost db

Exporting from remote

bcp my_table_name out ~/my_table_name.txt -S yourdb.database.secure.windows.net -U yourusername -P 'YourStrongPassword123!!' -d mydbname -c -t ','

 

Import to Local

bcp my_table_name in ~/my_table_name.txt -S localhost -U sa -P 'PrashantBhusal1' -d my_local_db_name -c -t ',' -q

**Output When Successful**

Starting copy...

5 rows copied.
Network packet size (bytes): 4096
Clock Time (ms.) Total : 16 Average : (312.5 rows per sec.)

Useful links

https://askubuntu.com/questions/870927/sqlcmd-not-available-after-installing-mssql-tools

https://docs.microsoft.com/en-us/sql/linux/sql-server-linux-troubleshooting-guide

https://docs.microsoft.com/en-us/sql/linux/sql-server-linux-troubleshooting-guide#connection

https://www.rootusers.com/how-to-install-microsoft-sql-server-on-ubuntu-linux/

https://github.com/rails-sqlserver/tiny_tds#install

Chart.js V2.6.0 override draw function

How I did this

Could not install Ruby 2.3.4 in Ubuntu 17.04 using RVM

I could not install Ruby 2.3.4 which I needed because Heroku does not support latest stable release like 2.4.0.  So my Gemfile has locked the version 2.3.4. Till now I have been manually commenting out that particular line from the Gemfile and skipping the change from Git-Commits.

Hack

I found a hack

• install ruby 2.3 from apt-get

sudo apt-get install ruby2.3 ruby2.3-dev

• find location of the ruby installed

which ruby2.3
# => /usr/bin/ruby2.3

• Mount the ruby to RVM

rvm mount /usr/bin/ruby2.3 -n ruby-2.3.3

rvm list                                

rvm rubies

 * ext-ruby-2.3.3 [ x86_64 ]
   ruby-1.8.7-p371 [ x86_64 ]
   ruby-1.9.3-p551 [ x86_64 ]
=> ruby-2.4.0 [ x86_64 ]

A better option

Install Ruby from archived link

rvm mount -r https://cache.ruby-lang.org/pub/ruby/2.3/ruby-2.3.3.tar.bz2

ActiveAdmin Login won’t show up but other one does

I have setup devise for one active-admin (AdminUser) and other for normal-user (User model).

This was config before

ActiveAdmin.routes(self)
devise_for :admin_users, ActiveAdmin::Devise.config

 

then I changed it to

devise_for :admin_users, ActiveAdmin::Devise.config
ActiveAdmin.routes(self)

Note: the order is important

  # this works
  devise_for :admin_users, ActiveAdmin::Devise.config
  ActiveAdmin.routes(self)

  # this won't work
  ActiveAdmin.routes(self)
  devise_for :admin_users, ActiveAdmin::Devise.config

Otherwise, your active-admin login won’t show up when you hit admin/login but normal login will show up(if you have setup devise for two models).