Update production storage to write to the Pure blob store

Modify the blob copying script to update the blob service name.

This completes the migration and allows us to (at some point) clean up
local disk and remove the "mirror" service from the config.

config/environments/production.rb

@@ -31,7 +31,7 @@ Rails.application.configure do
   # config.action_dispatch.x_sendfile_header = "X-Accel-Redirect" # for NGINX
 
   # Store uploaded files on the local file system (see config/storage.yml for options).
-  config.active_storage.service = :mirror
+  config.active_storage.service = :purestorage
 
   # Mount Action Cable outside main process or domain.
   # config.action_cable.mount_path = nil

config/storage.yml

@@ -20,6 +20,7 @@ purestorage:
   access_key_id: <%= Rails.application.credentials.dig(:active_storage, :purestorage_service, :access_key_id) %>
   secret_access_key: <%= Rails.application.credentials.dig(:active_storage, :purestorage_service, :secret_access_key) %>
 
+# TODO: remove this after we update existing blobs' service names to purestorage.
 mirror:
   service: Mirror
   primary: purestorage

script/copy-blobs-to-pure.rb

@@ -16,7 +16,10 @@ def migrate(source_service_name, target_service_name)
     target_service = ActiveStorage::Blob.services.fetch(target_service_name)
 
     ActiveStorage::Blob.find_each do |blob|
-      if target_service.exist?(blob.key)
+      if target_service.name.to_sym == blob.service_name.to_sym
+        report[:skipped] += 1
+        putc "-"
+      elsif target_service.exist?(blob.key)
         report[:skipped] += 1
         putc "S"
       else
@@ -31,7 +34,9 @@ def migrate(source_service_name, target_service_name)
           putc "E"
         end
       end
-      # blob.update_attribute :service_name, target_service_name
+
+      # Update the service name of the blob.
+      blob.update_column :service_name, target_service_name
     end
 
     puts