To make this work, you will need to place your databases on persistent Volumes as your deployment image will get overwritten the next time you deploy.
Volumes are limited to one host, this currently means that fly.io hosted Rails applications that use sqlite3 for their database can’t be deployed to multiple regions.
But if you are okay using beta software, LiteFS could work for multi-region sync, check it out! But this guide assumes you have one node and one volume.
Following are the steps required to make this work:
fly volumes create name
name with your desired volume name. Only alphanumeric characters and
underscores are allowed in names.
Optionally, you may specify the size of the volume, in gigabytes, by adding a
--size int argument.
The default volume size is 3 gigabytes.
Now set the following secret, again replacing the name with what you selected:
fly secrets set DATABASE_URL=sqlite3:///mnt/name/production.sqlite
Add the following to your
fly.toml, once again replacing the name with what you selected, this
time in two places:
[mounts] source="name" destination="/mnt/name"
Next move the dependency on the
db:migrate task from the
# commands used to deploy a Rails application namespace :fly do # BUILD step: # - changes to the filesystem made here DO get deployed # - NO access to secrets, volumes, databases # - Failures here prevent deployment task :build => 'assets:precompile' # RELEASE step: # - changes to the filesystem made here are DISCARDED # - full access to secrets, databases # - failures here prevent deployment - task :release => 'db:migrate' + task :release # SERVER step: # - changes to the filesystem made here are deployed # - full access to secrets, databases # - failures here result in VM being stated, shutdown, and rolled back # to last successful deploy (if any). - task :server do + task :server => 'db:migrate' do sh 'bin/rails server' end end
You can also silence warnings about running sqlite3 in production by adding the following line to config/environments/production.rb:
Rails.application.configure do + config.active_record.sqlite3_production_warning=false
These changes can be deployed using