## Connect Postgres for Django

### Summary
Connect a Django app to PostgreSQL on Ample. Read DATABASE_URL at runtime with dj-database-url with psycopg: when you supply one with --env it is delivered encrypted and takes precedence; when you supply none and the app needs PostgreSQL, Ample auto-provisions a managed PostgreSQL 16 database and injects its connection string.

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

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

### Infrastructure Requirements
1. **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.
2. **Postgres**  
   Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.

### Framework and Workload
- **Framework:** Django  
- **Workload:** Connect Postgres

### Release Status
- **Status:** published  
- **Support Status:** verified  
- **Execution Status:** ready

### Prerequisites
- dj-database-url with psycopg reading the DATABASE_URL environment variable at runtime
- Either a production DATABASE_URL to pass with --env, or nothing (auto-provision)
- An Ample account token with servers:write and databases:read

### Workflow Steps
1. **Read the URL at runtime**
   Open connections from the DATABASE_URL environment variable inside the app; never commit credentials and never connect at build time.
2. **Choose the source of the database**
   Pass --env DATABASE_URL=... for an existing database, or omit it to let Ample provision a managed one on first deploy and reuse it on redeploys.  
   Command: `ample deploy . --name  --public --start "python3 run.py"`
3. **Test the connection through the app**
   Expose a route (/db) that runs a trivial query and returns postgres=ok.
4. **Verify**
   Fetch the live URL and run the success checks below. On failure read the build log, then the runtime log, fix the cause and deploy again; do not blind-retry.  
   Command: `ample logs  --kind build`

### Limitations
- Verified on the node-22 template at s-1vcpu-1gb; other templates and sizes are not verified by this recipe.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified.
- Apps and their managed databases are placed together; cross-node shared databases are unsupported.

### Cost Estimate
- **Currency:** USD  
- **Monthly Amount:** 10.0  
- **Note:** Apps and managed databases auto-pause when idle; the estimate is the always-on monthly price of the tested sizes. Plan quotas and budgets apply.
 
#### Cost Breakdown
- **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

### Examples
- **Django + PostgreSQL canary**  
  Auto-provisioned managed database with a real query.
   
  **Source Ref:** tests/deploy-canaries/django-postgres

### Success Checks
1. **Database route reports a live connection**  
   Kind: http_get  
   Path: /db  
   Expect: postgres=ok

### Evidence Summary
1. **Canary run**  
   Summary: Django 5 project with dj-database-url and psycopg: the managed PostgreSQL database was auto-provisioned, python3 manage.py migrate ran as the release command, and /db and /migrated reported postgres=ok and the migrated marker.  
   Observed At: 2026-09-20T01:42:25Z  
   Implementation Revision: 199ff1dfd52683832ae75d3f98b53a7a4bff7f96-dirty (CLI e3181f5)  
   Expires At: 2027-03-19T01:42:25Z
2. **Canary run**  
   Summary: Node app needing PostgreSQL with no DATABASE_URL: a managed database was auto-provisioned and /db reported postgres=ok.  
   Observed At: 2026-09-19T23:55:33Z  
   Implementation Revision: 1764076-tls-account-903d345  
  Expires At: 2027-03-18T23:55:33Z