# Connect Postgres for Echo

## Summary
Database connection for an Echo app on Ample. Verified on Echo: a managed PostgreSQL database auto-provisioned and injected as DATABASE_URL, with real queries succeeding at request time (records=ok). Build and start: `CGO_ENABLED=0 go build -o app ./...` then `./app` on the ubuntu-24.04 template (go.sum committed for a reproducible build).

## Representative Queries
- Connect Postgres for Echo
- Where can I host Connect Postgres built with Echo?
- I need driver setup, connection settings, secret handling and a real connection test.

## Resource Requirements
- primitive:compute
- primitive:postgres

## Infrastructure Requirements
- **Compute**  
  Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.
- **Postgres**  
  Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.

## Prerequisites
1. A Echo project (CGO_ENABLED=0 go build -o app ./... then ./app on the ubuntu-24.04 template (go.sum committed for a reproducible build))
2. A PostgreSQL driver reading DATABASE_URL at runtime
3. An Ample account token with servers:write, databases:read

## Workflow Steps
1. **Build and start**  
   `CGO_ENABLED=0 go build -o app ./...` then `./app` on the ubuntu-24.04 template (go.sum committed for a reproducible build); the server must bind 0.0.0.0 on PORT.
2. **Read DATABASE_URL at runtime**  
   Open connections from the environment inside handlers or a pool; omit DATABASE_URL to auto-provision a managed database or pass `--env DATABASE_URL=...` for an existing one.
3. **Verify**  
   Fetch the live URL and `/p/relational-records` on the example; on failure read the build and runtime logs.  
   Command: `ample logs --kind build`

## Examples
### Echo pattern fixture
**Description:** Verified database connection on Echo.
**Source Ref:** tests/deploy-canaries/echo-patterns

## Success Checks
- **App responds on its public URL**  
   Kind: http_get  
   Path: `/`  
   Expect: ample canary echo patterns
- **Relational-records check from the example**  
   Kind: http_get  
   Path: `/p/relational-records`  
   Expect: see the pattern fixture checks

## Limitations
- Verified on the ubuntu-24.04 template at s-1vcpu-1gb; other sizes and Echo major versions are not verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified.

## Cost Estimate
- **Currency:** USD  
- **Monthly Amount:** 10.0  
- **Components:**  
  - App server, size: s-1vcpu-1gb, quantity: 1.0, monthly amount: 5.0  
  - Managed PostgreSQL database, size: s-1vcpu-1gb, quantity: 1.0, monthly amount: 5.0  
- **Note:** Always-on monthly price of the tested sizes; apps auto-pause when idle.

## Evidence Summary
- **Kind:** canary_run  
  **Summary:** Echo pattern fixture deployed on Ample (CGO_ENABLED=0 go build -o app ./... then ./app on the ubuntu-24.04 template (go.sum committed for a reproducible build)); for this guide: a managed PostgreSQL database auto-provisioned and injected as DATABASE_URL, with real queries succeeding at request time (records=ok).  
  **Observed At:** 2026-09-21T02:34:39Z  
  **Implementation Revision:** 1d28ae0-dirty (CLI 0.1.21)  
  **Expires At:** 2027-03-20T02:34:39Z  
  **Scope:**  
  - Checks: /p/relational-records  
  - Template: ubuntu-24.04