# Migrate Amazon S3 bucket: Public media library

Move object storage from Amazon S3 bucket to Ample, one component at a time. Destination verified on Ample: an object written to a published bucket with an immutable Cache-Control header, a mapping row, and the CDN URL serving it publicly.

## Source procedure:
1. Inventory the bucket (object count, total size, prefixes, largest objects) with `aws s3 ls --recursive --summarize`.
2. Not migrated automatically: Bucket policies, IAM conditions, lifecycle rules, versioning, replication and event notifications are not migrated; only PutObject and GetObject are verified on Ample.

## Cutover:
Switch the app's S3_* environment to the Ample bucket with a redeploy, verify reads and writes, keep the source bucket 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 Amazon S3 bucket provides beyond the component you are moving. 
   - Out of scope here: Bucket policies, IAM conditions, lifecycle rules, versioning, replication and event notifications are not migrated; only PutObject and GetObject are verified on Ample.
2. **Source step 1**: Inventory the bucket (object count, total size, prefixes, largest objects) with `aws s3 ls --recursive --summarize`.
3. **Source step 2**: Copy objects with `rclone sync` or `aws s3 sync` from the S3 bucket 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.
   - 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/public-media-library).
7. **Cut over**: Switch the app's S3_* environment to the Ample bucket with a redeploy, verify reads and writes, keep the source bucket 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.

## Cost Estimate
- **Currency**: USD
- **Monthly Amount**: 5.0
- **Basis**: Size prices from pricing.toml (loaded by the API).
   - **Components**:
     - App server: size: s-1vcpu-1gb, quantity: 1.0, monthly amount: 5.0
- **Note**: Destination always-on monthly price of the tested sizes; apps auto-pause when idle.

## Limitations
- Documentation only: nothing is executed automatically and no execution binding is offered.
- The source-side procedure is documented from Amazon S3 bucket's standard tooling and was not executed in this catalog's evidence.
- No full source-product parity is claimed: Bucket policies, IAM conditions, lifecycle rules, versioning, replication and event notifications are not migrated; only PutObject and GetObject are verified on Ample.
- Verified on the node-22 template at s-1vcpu-1gb.

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For more detailed reference, you can find this migration guide in different formats:
- [HTML](/content/migrate/amazon-s3-bucket/public-media-library/index.html)
- [Markdown](/content/migrate/amazon-s3-bucket/public-media-library.md)