Containers: Docker-in-Docker Runner

A minimal example that deploys a Cloudflare Container exposing one API to run a Docker image by reference and return its output.

API

• POST /run
  • Body: { "image": "<image-ref>" } (e.g. hello-world, alpine:3.20)
  • Runs: docker run --rm <image-ref> inside the container
  • Response JSON:
    • exit_code — process exit code
    • stdout — container stdout
    • stderr — container stderr
    • image — the provided image reference

Example:

curl -s https://<your-app-domain>/run \
  -H "Content-Type: application/json" \
  -d '{"image":"hello-world"}' | jq .

Code Layout

• Worker entry: src/index.ts
• Container app: container_src/app.py (Flask on port 8080)
• Dockerfile: Dockerfile

Deploy

npx wrangler deploy

Notes

• This runs arbitrary images. For production, consider authentication, allowlists, or network controls.
• The container listens on port 8080 and exposes POST /run.