Rails 5 how to clear or delete production postgres database

I am trying to delete a production database so I can start fresh. When I upgraded to rails 5 from rails 4, it is now protecting the production database from accidental deletion. It shows the following error message when I run rake db:reset.

/app# rake db:reset
  ActiveRecord::SchemaMigration Load (1.8ms)  SELECT "schema_migrations".* FROM "schema_migrations"
   (1.6ms)  SELECT "ar_internal_metadata"."value" FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1  [["key", :environment]]
  ActiveRecord::SchemaMigration Load (0.2ms)  SELECT "schema_migrations".* FROM "schema_migrations"
   (0.3ms)  SELECT "ar_internal_metadata"."value" FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1  [["key", :environment]]
  ActiveRecord::SchemaMigration Load (0.3ms)  SELECT "schema_migrations".* FROM "schema_migrations"
   (0.2ms)  SELECT "ar_internal_metadata"."value" FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1  [["key", :environment]]
rake aborted!
ActiveRecord::ProtectedEnvironmentError: You are attempting to run a destructive action against your 'production' database.
If you are sure you want to continue, run the same command with the environment variable:
DISABLE_DATABASE_ENVIRONMENT_CHECK=1
/usr/local/bundle/gems/activerecord-5.0.0.1/lib/active_record/tasks/database_tasks.rb:51:in `check_protected_environments!'
/usr/local/bundle/gems/activerecord-5.0.0.1/lib/active_record/railties/databases.rake:11:in `block (2 levels) in <top (required)>'
/usr/local/bundle/gems/rake-11.3.0/exe/rake:27:in `<top (required)>'
Tasks: TOP => db:reset => db:drop => db:check_protected_environments
(See full trace by running task with --trace)

It says that my adding the environment variable DISABLE_DATABASE_ENVIRONMENT_CHECK=1 to the command should work but it does not. I run it and it does nothing.

<606723-x9dh4:/app# DISABLE_DATABASE_ENVIRONMENT_CHECK=1 rake db:reset       
  ActiveRecord::SchemaMigration Load (1.6ms)  SELECT "schema_migrations".* FROM "schema_migrations"

Anyone know what I am doing wrong? Appreciate the help!

UPDATE:

My server is deployed using kubernetes. I am guessing that I am not able to reset the database because the server is running.

Try this it worked for me:

RAILS_ENV=production rake db:drop DISABLE_DATABASE_ENVIRONMENT_CHECK=1 

in a single line.