### Migrate AWS EC2 app: Express

Move Express compute from AWS EC2 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 instance (systemd unit or process manager config) into an env file kept out of the repository. Not migrated automatically: Cron jobs, local files on the instance disk, security-group networking and IAM instance roles are not migrated; use managed databases, buckets and encrypted env instead.  
Cutover: Add the custom domain with `ample domain add`, update DNS from the instance or load balancer, keep the instance until verified, then stop 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 AWS EC2 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 AWS EC2 app provides beyond the component you are moving. Out of scope here: Cron jobs, local files on the instance disk, security-group networking and IAM instance roles are not migrated; use managed databases, buckets and encrypted env instead.
2. **Source step 1**  
   Collect the process environment from the instance (systemd unit or process manager config) into an env file kept out of the repository.
3. **Source step 2**  
   Replace the instance's process manager with the repository's start command; Ample supervises the process and restarts it.
4. **Source step 3**  
   Inventory what else runs on the instance: databases, cron, reverse proxy rules, local files.
5. **Deploy on Ample in parallel**  
   `npm install, npm run build --if-present, npm run start` on the node-22 template. Pass the exported variables with `--env`; keep the source running.
   
   Command: `ample deploy . --name --public --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 instance or load balancer, keep the instance until verified, then stop 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.

#### Limitations
- Documentation only: nothing is executed automatically and no execution binding is offered.  
- The source-side procedure is documented from AWS EC2 app'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: Cron jobs, local files on the instance disk, security-group networking and IAM instance roles are not migrated; use managed databases, buckets and encrypted env instead.  
- Verified on the node-22 template at s-1vcpu-1gb; region, compliance and request-duration limits are unknown.  
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures on the managed side are not verified beyond the pattern checks.

#### Cost Estimate
**Currency**: USD
**Monthly Amount**: 10.0
**Components:**
- App server: s-1vcpu-1gb, quantity: 1.0, monthly amount: 5.0
- Managed PostgreSQL database: 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.