If you’re deploying a large migration or need to disable access to your application for some length of time, you can use Heroku’s built in maintenance mode. It will serve a static page to all visitors, while still allowing you to run rake tasks or console commands.

Usage

Enable it like so:

$ heroku maintenance:on
Maintenance mode enabled.

Once your application is ready, you can disable maintenance mode with:

$ heroku maintenance:off
Maintenance mode disabled.

Customization

You can also create your own content to display when your application goes into maintenance mode using the Custom Error Pages add-on.

To use, install the add-on and set your MAINTENANCE_PAGE_URL:

$ heroku addons:add custom_error_pages
Adding custom_error_pages to myapp...done.

$ heroku config:add MAINTENANCE_PAGE_URL=http://s3.amazonaws.com/your_bucket/your_maintenance_page.html

See the Custom Error Pages docs for full details.