# Migrate CloudFront distribution: Public image delivery

Move CDN delivery from CloudFront distribution to Ample, one component at a time. Destination verified on Ample: public objects in a published bucket served from the CDN URL, kept separate from private objects in an unpublished bucket that require authorization (private=ok only for the allowed role).

## Source procedure:
- Record the distribution's origins, cache behaviors, TTLs and the object keys the app references.
- Not migrated automatically: CloudFront cache behaviors, Lambda@Edge and CloudFront Functions, signed URLs and custom TTLs are not migrated; Ample verifies delivery of published bucket objects only.

## Cutover:
- Redeploy the app with the new asset base URL, verify delivery from the CDN URL, keep the distribution until confirmed, then disable it.

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

## Prerequisites:
- Authorized access to the CloudFront distribution source and its export tooling.
- An inventory of every component in scope and out of scope.
- A validated backup or copy before any cutover.
- An Ample account token with servers:write, buckets:write.

## Workflow Steps:
1. **Inventory the source**: List what CloudFront distribution provides beyond the component you are moving. Out of scope here: CloudFront cache behaviors, Lambda@Edge and CloudFront Functions, signed URLs and custom TTLs are not migrated; Ample verifies delivery of published bucket objects only.
2. **Source step 1**: Record the distribution's origins, cache behaviors, TTLs and the object keys the app references.
3. **Source step 2**: Copy the public assets into a published Ample bucket under versioned keys with immutable Cache-Control.
4. **Source step 3**: Update the app to build asset URLs from the Ample public URL.
5. **Publish the destination bucket**: Create and publish the asset bucket, upload versioned assets with immutable Cache-Control, and point the app at the public URL. Command: `ample bucket publish`.
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**: Redeploy the app with the new asset base URL, verify delivery from the CDN URL, keep the distribution until confirmed, then disable it.
8. **Rollback**: Point DNS or configuration back to the source. The source was never modified; deletion is a separate, user-executed step after validation.

## Examples:
### Next.js pattern fixture (destination)
- **Description**: Verified destination basis: public image delivery.
- **Source Reference**: `tests/deploy-canaries/next-js-patterns`

## Success Checks:
- **Destination app responds on its public URL**: Kind: `http_get`, Path: `/`, Expect: `ample canary next js patterns`
- **Public-media-library check from the destination example**: Kind: `http_get`, Path: `/p/public-media-library`, Expect: `see the pattern fixture checks`
- **Data or object counts and checksums match the source**: Kind: `manual`, Expect: `operator comparison before cutover`

## Limitations:
- Documentation only: nothing is executed automatically and no execution binding is offered.
- The source-side procedure is documented from CloudFront distribution'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: CloudFront cache behaviors, Lambda@Edge and CloudFront Functions, signed URLs and custom TTLs are not migrated; Ample verifies delivery of published bucket objects only.
- Verified on the node-22 template at s-1vcpu-1gb; region, compliance and request-duration limits are unknown.
- PutObject and GetObject with path-style addressing are verified; bulk copy tooling and other S3 operations are not.

## Cost Estimate:
- **Currency**: USD
- **Monthly Amount**: 5.0
- **Basis**: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty.
  - **Components**:
    - **Name**: 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. Source costs are unknown to Ample.

## Evidence Summary:
- **Kind**: canary_run
- **Summary**: Destination side verified: the Next.js pattern fixture deployed on Ample (next build then next start -H 0.0.0.0 -p $PORT on the node-22 template) and its checks passed (public objects in a published bucket served from the CDN URL, kept separate from private objects in an unpublished bucket that require authorization (private=ok only for the allowed role)). The source-side export from CloudFront distribution 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
- **Scope**:
  - **Checks**: `/p/public-media-library`
  - **Destination Only**: true
  - **Template**: node-22

## Next Actions:
1. **Action ID**: browse-catalog  
   **Label**: Browse the catalog index  
   **Operation ID**: catalog_index  
   **Method**: GET  
   **Relative Path**: /v1/catalog

2. **Action ID**: search-recipes  
   **Label**: Search published recipes by intent, stack and constraints  
   **Operation ID**: search_recipes  
   **Method**: POST  
   **Relative Path**: /v1/catalog/search  
   **Parameters**: {"body":{"limit":5,"query":"Migrate CloudFront distribution: Public image delivery"}}

3. **Action ID**: plan:page:migrate:cloudfront-distribution:public-image-delivery  
   **Label**: Prepare a side-effect-free deployment plan for an authorized project  
   **Operation ID**: plan_deployment  
   **Method**: POST  
   **Relative Path**: /v1/catalog/plan  
   **Parameters**: {"body":{"inputs":{},"projectId":"","recipeId":"page:migrate:cloudfront-distribution:public-image-delivery","recipeRevision":"r1"}}

4. **Action ID**: auth-setup  
   **Label**: Read the existing agent authentication setup  
   **Operation ID**: existing_auth_setup  
   **Method**: GET  
   **Relative Path**: /mcp/setup

5. **Action ID**: browse:migration:cloudfront-distribution  
   **Label**: Browse CloudFront distribution  
   **Operation ID**: browse_node  
   **Method**: GET  
   **Relative Path**: /v1/catalog/nodes/migration%3Acloudfront-distribution

6. **Action ID**: browse:pattern:public-image-delivery  
   **Label**: Browse Public image delivery  
   **Operation ID**: browse_node  
   **Method**: GET  
   **Relative Path**: /v1/catalog/nodes/pattern%3Apublic-image-delivery

7. **Action ID**: browse:intent:migrate-cdn  
   **Label**: Browse Migrate CDN  
   **Operation ID**: browse_node  
   **Method**: GET  
   **Relative Path**: /v1/catalog/nodes/intent%3Amigrate-cdn