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Diffstat (limited to 'guides/source/active_storage_overview.md')
| -rw-r--r-- | guides/source/active_storage_overview.md | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/guides/source/active_storage_overview.md b/guides/source/active_storage_overview.md index 615f576797..54f8f5c2b5 100644 --- a/guides/source/active_storage_overview.md +++ b/guides/source/active_storage_overview.md @@ -41,6 +41,10 @@ application (or upgrading your application to Rails 5.2), run `rails active_storage:install` to generate a migration that creates these tables. Use `rails db:migrate` to run the migration. +WARNING: `active_storage_attachments` is a polymorphic join table that stores your model's class name. If your model's class name changes, you will need to run a migration on this table to update the underlying `record_type` to your model's new class name. + +WARNING: If you are using UUIDs instead of integers as the primary key on your models you will need to change the column type of `record_id` for the `active_storage_attachments` table in the generated migration accordingly. + Declare Active Storage services in `config/storage.yml`. For each service your application uses, provide a name and the requisite configuration. The example below declares three services named `local`, `test`, and `amazon`: @@ -189,14 +193,21 @@ gem "google-cloud-storage", "~> 1.11", require: false ### Mirror Service -You can keep multiple services in sync by defining a mirror service. When a file -is uploaded or deleted, it's done across all the mirrored services. Mirrored -services can be used to facilitate a migration between services in production. -You can start mirroring to the new service, copy existing files from the old -service to the new, then go all-in on the new service. Define each of the -services you'd like to use as described above and reference them from a mirrored +You can keep multiple services in sync by defining a mirror service. A mirror +service replicates uploads and deletes across two or more subordinate services. + +A mirror service is intended to be used temporarily during a migration between +services in production. You can start mirroring to a new service, copy +pre-existing files from the old service to the new, then go all-in on the new service. +NOTE: Mirroring is not atomic. It is possible for an upload to succeed on the +primary service and fail on any of the subordinate services. Before going +all-in on a new service, verify that all files have been copied. + +Define each of the services you'd like to mirror as described above. Reference +them by name when defining a mirror service: + ```yaml s3_west_coast: service: S3 @@ -219,9 +230,12 @@ production: - s3_west_coast ``` -NOTE: Files are served from the primary service. +Although all secondary services receive uploads, downloads are always handled +by the primary service. -NOTE: This is not compatible with the [direct uploads](#direct-uploads) feature. +Mirror services are compatible with direct uploads. New files are directly +uploaded to the primary service. When a directly-uploaded file is attached to a +record, a background job is enqueued to copy it to the secondary services. Attaching Files to Records -------------------------- @@ -386,6 +400,10 @@ helper allows you to set the disposition. rails_blob_path(user.avatar, disposition: "attachment") ``` +WARNING: To prevent XSS attacks, ActiveStorage forces the Content-Disposition header +to "attachment" for some kind of files. To change this behaviour see the +available configuration opions in [Configuring Rails Applications](configuring.html#configuring-active-storage). + If you need to create a link from outside of controller/view context (Background jobs, Cronjobs, etc.), you can access the rails_blob_path like this: |