# Containerization

## Docker Image

**Base image**: `mcr.microsoft.com/dotnet/aspnet:10.0` (was `:8.0` through cycle 3 — bumped by AZ-500)
**Build image**: `mcr.microsoft.com/dotnet/sdk:10.0` (was `:8.0` through cycle 3 — bumped by AZ-500)
**Build strategy**: Multi-stage (restore → build → publish → runtime)
**Exposed ports**: 8080 (HTTP), 8081 (management/metrics)

## Container Composition (docker-compose.yml)

| Service | Image | Ports (host:container) | Purpose |
|---------|-------|------------------------|---------|
| postgres | postgres:16 | 5433:5432 | Database (host port 5433 chosen to avoid conflicts with sibling-project Postgres instances on dev laptops) |
| api | Custom (Dockerfile) | 18980:8080, 18981:8081 | Application |

## Volumes

| Mount | Container Path | Purpose |
|-------|---------------|---------|
| ./tiles | /app/tiles | Tile image storage |
| ./ready | /app/ready | Output artifacts (CSV, summary, stitched, ZIP) |
| ./logs | /app/logs | Serilog file output |
| postgres_data (named) | /var/lib/postgresql/data | Database persistence |

## Health Checks

- **PostgreSQL**: `pg_isready -U postgres` (interval 5s, timeout 5s, retries 5)
- **API**: depends on postgres health (startup ordering)

## Environment Variables

| Variable | Source | Purpose |
|----------|--------|---------|
| ASPNETCORE_ENVIRONMENT | docker-compose | Environment selection |
| ASPNETCORE_URLS | docker-compose | Listen address |
| ConnectionStrings__DefaultConnection | docker-compose | DB connection string |
| MapConfig__ApiKey | Host env `GOOGLE_MAPS_API_KEY` | Google Maps API key |
| AZAION_REVISION | Build arg (CI_COMMIT_SHA) | Git revision tracking |

## Build Labels (OCI)

- `org.opencontainers.image.revision` — Git commit SHA
- `org.opencontainers.image.created` — Build timestamp
- `org.opencontainers.image.source` — Repository URL
