Durable Object-managed Containers demo

A minimal Worker whose Durable Objects start namespace-backed containers on demand.

Prerequisites

• Node.js, pnpm, and Docker
• A Cloudflare account with Workers, Containers, and the new runtime enabled.

Deploy

Install dependencies:

pnpm install

Use the preview Wrangler build from workers-sdk PR #15480 until it is upstream.

Authenticate, then deploy with the Wrangler PR build:

npx --yes https://pkg.pr.new/wrangler@15480 whoami
npx --yes https://pkg.pr.new/wrangler@15480 deploy

Wrangler builds and pushes the image, prepares it to run on Cloudflare, uploads the Worker, and creates the namespace-backed application.

Try it

Use the Worker URL printed by Wrangler:

curl "https://<worker-url>/?instance=first"
curl "https://<worker-url>/_status?instance=first"
curl "https://<worker-url>/_destroy?instance=first"

Each instance value selects a different Durable Object and container.

What changed

• The top-level containers[] entry attaches a Durable Object-managed application to the Sandbox namespace.
• scheduling_policy: "durable_object" makes each Durable Object own its container lifecycle.
• The named images.app configuration tells Wrangler to build, push, and prepare the image.
• Wrangler exposes prepared images through the class-scoped env.EXPERIMENTAL_CLOUDFLARE_CONTAINER_IMAGES map.