Migrate Backblaze B2 S3 bucket: Tenant-scoped object prefixes

Move object storage from Backblaze B2 S3 bucket to Ample, one component at a time. Destination verified on Ample: every tenant's objects stored under tenants// in a private bucket with an ownership row per object, reads refused for keys outside the caller's prefix or not owned (cross=forbidden), and a prefix-bound listing returning only that tenant's objects (own=1).

Source procedure:

• Inventory the bucket with rclone size or the B2 dashboard.
• Not migrated automatically: B2 file versions, lifecycle rules and application-key restrictions are not migrated.

Cutover:

Switch the app's S3_* environment to the Ample bucket with a redeploy, verify reads and writes, keep B2 read-only until confirmed.

Rollback:

Keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide.

Workflow Steps

1. Inventory the source

   • List what Backblaze B2 S3 bucket provides beyond the component you are moving.
   • Out of scope here: B2 file versions, lifecycle rules and application-key restrictions are not migrated.

2. Source step 1

   • Inventory the bucket with rclone size or the B2 dashboard.

3. Source step 2

   • Copy objects with rclone sync from the B2 S3-compatible endpoint to the Ample bucket endpoint using the issued credentials (path-style).

4. Source step 3

   • Verify a sample of objects by size and checksum after the copy.

5. Create the destination bucket and copy

   • Create the bucket, copy with rclone or the S3 CLI in path-style mode using the issued credentials, then pass the credentials to the app as encrypted S3_* variables.
   • Command: ample bucket create --name

6. Validate before cutover

   • Run the app's own checks and, for data, compare counts and checksums; the example checks are the pattern self-tests (/p/tenant-scoped-object-prefixes).

7. Cut over

   • Switch the app's S3_* environment to the Ample bucket with a redeploy, verify reads and writes, keep B2 read-only until confirmed.

8. Rollback

   • Point DNS or configuration back to the source. The source was never modified; deletion is a separate, user-executed step after validation.

Limitations

• Documentation only: nothing is executed automatically and no execution binding is offered.
• The source-side procedure is documented from Backblaze B2 S3 bucket's standard tooling and was not executed in this catalog's evidence; the destination side was verified with the pattern fixture.
• No full source-product parity is claimed: B2 file versions, lifecycle rules and application-key restrictions are not migrated.
• Verified on the node-22 template at s-1vcpu-1gb; region, compliance and request-duration limits are unknown.

Cost Estimate

• Currency: USD
• Monthly Amount: $5.00
• Basis: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty.
• Components:
  • App server: size s-1vcpu-1gb, quantity 1.0, monthly amount $5.00.

Evidence Summary

• Kind: canary_run
• Summary: Destination side verified: the Express pattern fixture deployed on Ample and its checks passed. The source-side export from Backblaze B2 S3 bucket is documented from the vendor's standard tooling and was not executed by this catalog's evidence.
• Observed At: 2026-09-21T02:34:39Z
• Implementation Revision: 1d28ae0-dirty (CLI 0.1.21)
• Expires At: 2027-03-20T02:34:39Z

Next Actions

• Browse the catalog index
• Search published recipes by intent, stack and constraints
• Prepare a side-effect-free deployment plan for an authorized project
• Read the existing agent authentication setup
• Browse Backblaze B2 S3 bucket
• Browse Tenant-scoped object prefixes
• Browse Migrate objects