Problem with migrating an Azure database for a Ruby application - ruby-on-rails

Question

I have a working Ruby on Rails app (running Ruby 2.2.10p489 and Rails 4.2.5 and activerecord-sqlserver-adapter 4.2.6) on a Linux server (Amazon AMI v 2018.03 rhel fedora). It connects to an Azure database. Everything works great. But when I migrate to a different Azure database and change the credentials to point to the new database, I get a long list of unhelpful errors that looks like so:
SystemStackError: stack level too deep
from /apps/acme_dynamite/path/ruby/2.2/gems/tiny_tds-1.0.5/lib/tiny_tds/client.rb:53:in `connect'
from /apps/acme_dynamite/path/ruby/2.2/gems/tiny_tds-1.0.5/lib/tiny_tds/client.rb:53:in `initialize'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-sqlserver-adapter-4.2.6/lib/active_record/connection_adapters/sqlserver_adapter.rb:280:in `new'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-sqlserver-adapter-4.2.6/lib/active_record/connection_adapters/sqlserver_adapter.rb:280:in `dblib_connect'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-sqlserver-adapter-4.2.6/lib/active_record/connection_adapters/sqlserver_adapter.rb:271:in `connect'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-sqlserver-adapter-4.2.6/lib/active_record/connection_adapters/sqlserver_adapter.rb:59:in `initialize'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-sqlserver-adapter-4.2.6/lib/active_record/sqlserver_base.rb:18:in `new'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-sqlserver-adapter-4.2.6/lib/active_record/sqlserver_base.rb:18:in `sqlserver_connection'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:438:in `new_connection'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:448:in `checkout_new_connection'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:422:in `acquire_connection'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:349:in `block in checkout'
from /usr/share/ruby/2.2/monitor.rb:211:in `mon_synchronize'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:348:in `checkout'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:263:in `block in connection'
from /usr/share/ruby/2.2/monitor.rb:211:in `mon_synchronize'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:262:in `connection'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:571:in `retrieve_connection'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-4.2.5/lib/active_record/connection_handling.rb:113:in `retrieve_connection'
from /apps/acme_dynamite/path/ruby/2.2/gems/activerecord-4.2.5/lib/active_record/connection_handling.rb:87:in `connection'
from (irb):1
from /apps/acme_dynamite/path/ruby/2.2/gems/railties-4.2.5/lib/rails/commands/console.rb:110:in `start'
from /apps/acme_dynamite/path/ruby/2.2/gems/railties-4.2.5/lib/rails/commands/console.rb:9:in `start'
from /apps/acme_dynamite/path/ruby/2.2/gems/railties-4.2.5/lib/rails/commands/commands_tasks.rb:68:in `console'
from /apps/acme_dynamite/path/ruby/2.2/gems/railties-4.2.5/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
from /apps/acme_dynamite/path/ruby/2.2/gems/railties-4.2.5/lib/rails/commands.rb:17:in `<top (required)>'
from bin/rails:4:in `require'
the working Azure connection looks something like:
env PRODUCTION_DATABASE_HOST="xxx.database.windows.net"
env PRODUCTION_DATABASE_PORT=1433
env PRODUCTION_DATABASE="databasename_no_dots"
env PRODUCTION_DATABASE_USERNAME="username_no_dots_or_ands"
env PRODUCTION_DATABASE_PASSWORD="supersecret"
the non-working one looks like:
env PRODUCTION_DATABASE_HOST="xxx2.database.windows.net"
env PRODUCTION_DATABASE_PORT=1433
env PRODUCTION_DATABASE="other_databasename_no_dots"
env PRODUCTION_DATABASE_USERNAME="username_no_dots_or_ands"
env PRODUCTION_DATABASE_PASSWORD="supersecret"
The problem is not connectivity or a firewall, because I can actually connect to this new Azure server using /node_modules/sql-cli. What could possibly be wrong? Some incompatibility between my version of Ruby and this other instance of Azure? I am out of ideas.
That pile of errors can be triggered from within irb just by issuing a statement like:
results = ActiveRecord::Base.connection.exec_query("SELECT 1")

Answer 1

UPDATE: the key to getting around this problem turned out to be the creation of a new Azure login/user (see https://azure.microsoft.com/en-us/blog/adding-users-to-your-sql-azure-database/ ). While the admin user you might be tempted to work with works fine for some database connections, in Ruby on Rails it is likely to fail in the unhelpful way described above. Trust me, you can avoid a lot of headaches if you set up some other app-specific SQL login first. All this could've been avoided had Ruby on Rails simply reported that the database user had insufficient permissions instead of getting caught in runaway recursion.

Answer 2

You could try:
env PRODUCTION_DATABASE_HOST="xxx2.database.windows.net"