ruby 32 lines · 8 steps

A Rake task to purge stale Active Storage blobs in Rails

A scheduled Rake task finds unattached Active Storage blobs older than 48 hours and purges them in batches, logging and reporting failures.

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Rails Intermediate rake active-storage batch-processing cleanup error-handling
1namespace :active_storage do
2 desc "Purge blobs that have been unattached for more than 48 hours"
3 task purge_stale: :environment do
4 cutoff = 48.hours.ago
5 scope = ActiveStorage::Blob.unattached.where(created_at: ..cutoff)
6 
7 total = scope.count
8 if total.zero?
9 Rails.logger.info("[active_storage:purge_stale] no stale blobs found")
10 next
11 end
12 
13 Rails.logger.info("[active_storage:purge_stale] purging #{total} stale blob(s)")
14 
15 purged = 0
16 failed = 0
17 
18 scope.find_each(batch_size: 250) do |blob|
19 blob.purge
20 purged += 1
21 rescue ActiveStorage::FileNotFoundError
22 blob.destroy
23 purged += 1
24 rescue => e
25 failed += 1
26 Rails.logger.error("[active_storage:purge_stale] failed to purge blob #{blob.id} (#{blob.key}): #{e.class} #{e.message}")
27 Sentry.capture_exception(e, extra: { blob_id: blob.id, key: blob.key }) if defined?(Sentry)
28 end
29 
30 Rails.logger.info("[active_storage:purge_stale] done: #{purged} purged, #{failed} failed")
31 end
32end
01 / 01
STEP 01

Walkthrough

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Three takeaways
  1. 1Batching with find_each keeps memory bounded when cleaning up potentially large result sets.
  2. 2Rescuing specific exceptions lets you handle known failure modes differently from unexpected ones.
  3. 3Counting successes and failures separately turns a maintenance task into an observable, auditable job.

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