page:migrate:digitalocean droplet app:fastapi

Migrate DigitalOcean Droplet app: FastAPI

Move FastAPI compute from DigitalOcean Droplet app to Ample, one component at a time. Destination verified on Ample: the app built, started and answered on its public HTTPS URL with encrypted configuration delivered. Source procedure: Collect the process environment from the droplet (systemd unit, PM2 or supervisor config) into an env file kept out of the repository. Not migrated automatically: Cron jobs, local upload directories and firewall rules are not migrated; move uploads to a bucket and data to a managed database. Cutover: Add the custom domain with ample domain add, update DNS from the droplet IP, keep the droplet until verified, then power it off. Rollback: keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide.

Prerequisites

• Authorized access to the DigitalOcean Droplet app 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, databases:read

Workflow Steps

1. Inventory the source
   List what DigitalOcean Droplet app provides beyond the component you are moving. Out of scope here: Cron jobs, local upload directories, and firewall rules are not migrated; move uploads to a bucket and data to a managed database.

2. Source step 1
   Collect the process environment from the droplet (systemd unit, PM2 or supervisor config) into an env file kept out of the repository.

3. Source step 2
   Replace the droplet's process manager and reverse proxy with the repository's start command; Ample provides HTTPS and supervision.

4. Source step 3
   Inventory what else runs on the droplet: databases, cron, local uploads.

5. Deploy on Ample in parallel
   ample deploy . --name --public --start "python3 run.py" --env-file .env.production

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/configuration-secrets, /p/relational-records).

7. Cut over
   Add the custom domain with ample domain add, update DNS from the droplet IP, keep the droplet until verified, then power it off.

8. Rollback
   Point DNS or configuration back to the source. The source was never modified; deletion is a separate, user-executed step after validation.

Success Checks

• Destination app responds on its public URL
• Configuration-secrets check from the destination example
• Relational-records check from the destination example
• Data or object counts and checksums match the source

Limitations

• Documentation only: nothing is executed automatically and no execution binding is offered.
• The source-side procedure is documented from DigitalOcean Droplet app's standard tooling and was not executed in this catalog's evidence; the destination side was verified with the pattern fixture.
• Verified on the python-3.12 template at s-1vcpu-1gb; region, compliance, and request-duration limits are unknown.

Examples

• FastAPI pattern fixture (destination): Verified destination basis: FastAPI compute.

Cost Estimate

• Currency: USD
• Monthly Amount: 10.0
• Components:
  • App server: s-1vcpu-1gb (monthly amount: 5.0)
  • Managed PostgreSQL database: s-1vcpu-1gb (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

• The source-side export from DigitalOcean Droplet app is documented from the vendor's standard tooling and was not executed by this catalog's evidence.