DA MSM - Multi-Site Management for Edge Delivery Services

A Cloudflare Worker that brings Multi-Site Management (MSM) inheritance capabilities to Adobe Edge Delivery Services, enabling content inheritance patterns similar to AEM's blueprint/livecopy architecture.

What is Multi-Site Management (MSM)?

Multi-Site Management (MSM) is a content management pattern that allows organizations to manage multiple websites efficiently by creating relationships between a base site (aka blueprint) and satellites (aka live copies). Key benefits include:

• Content Reuse: Share content across multiple sites while maintaining consistency
• Efficient Updates: Changes to the blueprint can be rolled out to live copies
• Selective Overrides: Live copies can override specific content while inheriting the rest

When content is requested from a satellite that doesn't exist or has been deleted, the system inherits from the base site.

What makes MSM on Edge Delivery different?

• Tranparency in authoring: Only the content that is truly unique to the satellite exists in the satelite. This creates immediately clarity when browsing this content.
• Inherited metadata support: Base Metadata is seamlessly stitched together with satelite Metadata. Satellite rows take precedence.
• Inherited redirects support: Base redirects are seamlessly merged with satellite redirects. Satellite rows take precedence when the URL key matches.
• De-prioritized Localization: Due to DA's existing and extensive localization feature-set, DA MSM is targeted at brand experience inheritance. We believe the two features are complimentary.

What This Worker Does

This Cloudflare Worker replicates the MSM inheritance behavior for Edge Delivery Services by:

1. Intercepting content requests in the format /org/site/path
2. Attempting a satellite fetch from the requested site location
3. Looking up the MSM config from the DA admin API to resolve the base site
4. Inheriting from the base site on 404
5. Merging satellite redirects with base redirects (satellite rows win on duplicate keys)
6. Preserving all request context including headers, query parameters, and authentication
7. Stitching satelite metadata with base metadata

Request Flow

┌─────────────────────────────────────────────────────────┐
│  Edge Delivery Services Site                            │
│  (fstab.yaml configured to use this worker)             │
└─────────────────────┬───────────────────────────────────┘
                      │
                      ▼
┌─────────────────────────────────────────────────────────┐
│  DA MSM Worker                                          │
│  https://da-msm.adobedev.workers.dev                    │
└─────────────────────┬───────────────────────────────────┘
                      │
                      ▼
┌─────────────────────────────────────────────────────────┐
│  Try Satellite: /acme/us-site/content/page              │
│  Status: 404                                            │
└─────────────────────┬───────────────────────────────────┘
                      │
                      ▼ MSM config lookup: us-site → global-site
┌─────────────────────────────────────────────────────────┐
│  Try Base: /acme/global-site/content/page               │
│  Status: 200 ✓                                          │
└─────────────────────────────────────────────────────────┘

Example mountpoint

mountpoints:
  /: https://da-msm.your-domain.workers.dev/acme/store-1

MSM Config Setup

The base-to-satellite mapping is managed in the DA config UI at da.live/config#/{org}/ under the msm tab. The sheet has three columns:

base	satellite	title
global-site		Global Site (base)
global-site	store-1	Store 1
global-site	store-2	Store 2

• base: The base (blueprint) site repo name
• satellite: The satellite (live copy) site repo name (empty for the base entry itself)
• title: A human-readable label

The worker fetches this config from the DA admin API and caches it in memory (5-minute TTL).

How It Works

1. Author Preview Request: An author sends a preview request to Edge Delivery for a satellite page
2. Worker Request: Edge Delivery requests the content from the MSM worker
3. Satellite Content Request: The worker requests the satellite content from DA
4. Content Overridden: If the content has been overridden in the satellite, this content is sent back to Edge Delivery
5. Inherit from Base: If the content has not been overridden, the worker looks up the MSM config for the satellite's base site and inherits content from there

Redirect Inheritance

When a request targets a redirect resource (/redirects or /redirects.json), the worker merges satellite and base redirects rather than using 404 fallback:

1. Both satellite and base redirects are fetched in parallel
2. Rows are merged using the first column (the source URL) as the key
3. Where the same key exists in both, the satellite row wins
4. The merged result is returned as a single JSON response

┌───────────────────────────────────────────────────────────┐
│  Base redirects (/acme/global-site/redirects)             │
│  /old-about  →  /about                                    │
│  /old-help   →  /help                                     │
│  /old-legal  →  /legal                                    │
└──────────────────────┬────────────────────────────────────┘
                       │  merge (base first)
                       ▼
┌───────────────────────────────────────────────────────────┐
│  Satellite redirects (/acme/store-1/redirects)            │
│  /old-about  →  /store-1/about        ← overrides base   │
│  /promo      →  /store-1/sale         ← satellite-only   │
└──────────────────────┬────────────────────────────────────┘
                       │  satellite wins on conflict
                       ▼
┌───────────────────────────────────────────────────────────┐
│  Merged result                                            │
│  /old-about  →  /store-1/about        (satellite)         │
│  /old-help   →  /help                 (inherited)         │
│  /old-legal  →  /legal                (inherited)         │
│  /promo      →  /store-1/sale         (satellite)         │
└───────────────────────────────────────────────────────────┘

If only one side has redirects (e.g., the satellite has none), the other side's data is returned as-is.

Usage

URL Structure

https://da-msm.your-domain.workers.dev/{org}/{site}/{path}

Parameters:

• org: Your organization identifier (e.g., "acme")
• site: The satellite site to fetch from (e.g., "us-site")
• path: The content path being requested

The base site is resolved automatically from the org's MSM config.

Use Cases

1. Brand Hierarchy

Sub-brands can inherit content from parent brands:

mountpoints:
  /: https://da-msm.worker.dev/acme/subbrand

2. Staging/Production Inheritance

Development sites can inherit production content:

mountpoints:
  /: https://da-msm.worker.dev/acme/dev

Environments

The worker supports multiple environments via Wrangler, each targeting a different DA content and admin origin.

Environment	Content Origin	Admin Origin	Worker Name
Production (default)	content.da.live	admin.da.live	da-msm
Stage	stage-content.da.live	stage-admin.da.live	da-msm-stage

Configuration in wrangler.toml:

[vars]
CONTENT_ORIGIN = "https://content.da.live"
ADMIN_ORIGIN = "https://admin.da.live"

[env.stage.vars]
CONTENT_ORIGIN = "https://stage-content.da.live"
ADMIN_ORIGIN = "https://stage-admin.da.live"

Each environment deploys as a separate worker with its own workers.dev endpoint, so your site's fstab.yaml can point to the appropriate one.

Development

Local Development

# Install dependencies
npm install

# Start local development server
npm run dev

# Test the worker locally
curl "http://localhost:8787/acme/us-site/content/test"

Deployment

# Deploy production worker
npm run deploy

# Deploy stage worker
npm run deploy:stage

After deployment, the endpoints will be:

• Production: https://da-msm.your-domain.workers.dev
• Stage: https://da-msm-stage.your-domain.workers.dev