# Compose & Infrastructure Conventions

This document outlines the standard conventions and best practices for Docker
and Podman Compose files, volume layouts, networking, and smart image packaging
across our infrastructure.

---

## 1. Storage & Host Volume Conventions

- **Root Project Directory:** All project state lives under
  `/volume1/docker/<stack-name>/` (e.g., `/volume1/docker/auth-yes/`,
  `/volume1/docker/spire/`).
- **Standard Folder Naming:** Always use **`data`** for persistent application
  and database storage (never `db` or fragmented subfolders when a single root
  directory suffices).
- **Local Bind Mount Syntax:** Always use the standard `driver_opts` local bind
  definition:
  ```yaml
  volumes:
    <service>-data:
      driver: local
      driver_opts:
        type: none
        device: ${<STACK>_DATA_PATH}
        o: bind
  ```
- **Zero-Trust Inter-Process Sockets:**
  - Sockets shared across stacks (e.g., the SPIFFE Workload API `agent.sock`)
    MUST use a **named volume** (`spire-socket`).
  - Application containers mount this volume read-only (`:ro`), ensuring zero
    access to sensitive server CA keys, SQLite databases, or internal host
    state.
  - Client stacks declare `spire-socket` as `external: true`.

---

## 2. Smart Container Images & Scripting Guidelines

- **Pragmatic Scripting in Compose:**
  - Short one-line commands, flags, or glue checks in `command:` or
    `entrypoint:` are fine.
  - Complex configuration generation, heredoc templating (`cat << 'EOF'`), and
    heavy lifecycle bootstrapping MUST NOT be embedded in Compose files.
- **Smart Image Packaging & Repository Segregation:**
  - Self-seeding configuration and container lifecycle scripts belong in the
    container image.
  - All smart image logic, Dockerfiles, entrypoint scripts (`entrypoint.sh`),
    and configuration templates (`templates/`) must be cleanly segregated in
    dedicated directories in the codebase (e.g., `spire/`).
- **Persistence & User Modification:**
  - Smart image entrypoints must follow the self-seeding pattern: check if the
    target configuration exists on the host mount.
  - If missing on first boot $\rightarrow$ atomically write the master template
    with guiding comments.
  - If already present $\rightarrow$ leave it untouched, preserving all user
    modifications across restarts and image updates.

---

## 3. Container Registries, Mirrors & Image Distribution

Our infrastructure uses a tiered registry architecture to balance local caching,
private custom image hosting, and universal build portability:

### 3.1 Registry Tier Classification

1. **Primary Custom Image Registry (`${REG}` $\rightarrow$ `quay.atyg.org`):**
   - Hosts all internally built, project-specific custom images
     (`${REG}/library/<image>:<tag>`).
   - Examples: `${REG}/library/auth-yes-api:latest`,
     `${REG}/library/spire-server:latest`, `${REG}/library/spire-agent:latest`.
   - Retention policy is set for **indefinite storage** (auto-pruning disabled).
2. **Docker Hub Pull-Through Cache (`acr.atyg.org`):**
   - Proxies and indefinitely caches upstream Docker Hub images on the local
     network.
   - Examples: `acr.atyg.org/library/postgres:18-alpine`,
     `acr.atyg.org/valkey/valkey:8-alpine`, `acr.atyg.org/library/alpine:3.20`.
3. **GHCR Pull-Through Mirror (`${GHCR_REG}` $\rightarrow$ `ghcr.atyg.org`):**
   - Proxies and caches GitHub Container Registry packages.
   - Examples: `${GHCR_REG}/spiffe/spire-server:1.9.3`,
     `${GHCR_REG}/spiffe/spire-agent:1.9.3`.

### 3.2 Universal Dockerfile Portability (Jules & External CI)

- **Public Upstream Defaults:** Dockerfiles must declare public upstream
  registries by default so external agents (like Jules) and cloud CI runners can
  build without private `.atyg.org` DNS:
  ```dockerfile
  ARG SPIRE_UPSTREAM=ghcr.io/spiffe/spire-server:1.9.3
  ARG BASE_IMAGE=alpine:3.20

  FROM ${SPIRE_UPSTREAM} AS upstream
  FROM ${BASE_IMAGE}
  ```
- **Local Build Acceleration:** Local builds and CLI scripts (`infra/setup.ts`)
  can optionally pass `--build-arg` to pull through local mirrors
  (`ghcr.atyg.org`, `acr.atyg.org`).
- **Push Destination:** Custom built images are tagged and pushed to the local
  authority `${REG}/library/...` (`quay.atyg.org`).

### 3.3 Compose Variable Cleanliness

- **No Inline Defaults:** Always write clean variable references in Compose
  files (`image: ${REG}/library/spire-server:latest`,
  `image: ${GHCR_REG}/spiffe/spire-server:1.9.3`).
- **Centralized Values:** Default registry variables belong strictly in `.env`
  and `infra/setup.ts`.

---

## 4. Networking & Traefik Routing

- **Ingress Network:**
  - Web-facing containers connect to the pre-existing external network
    `traefik-net` (`external: true`).
- **Network Routing Ambiguity Guard:**
  - Whenever a service connects to more than one network (e.g., internal
    bridge + `traefik-net`), always specify:
    ```yaml
    labels:
      - "traefik.docker.network=traefik-net"
    ```
- **Internal Service Mesh:**
  - Backends, databases, Valkey, and internal daemons communicate over a project
    bridge network (e.g., `auth-internal-net`) without exposing ports directly
    to the host.
- **Standard Websecure Labels:**
  ```yaml
  labels:
    - "traefik.enable=true"
    - "traefik.docker.network=traefik-net"
    - "traefik.http.routers.<app>.rule=Host(`${SYSTEM_DOMAIN}`)"
    - "traefik.http.routers.<app>.entrypoints=websecure"
    - "traefik.http.routers.<app>.tls=true"
    - "traefik.http.services.<app>.loadbalancer.server.port=<port>"
  ```

---

## 5. Stack Independence & Decoupling

- **Standalone Infrastructure Stacks:**
  - General-purpose infrastructure components (e.g., SPIRE, Auth-Yes, Registry
    Caches) are standalone stacks with their own dedicated project directories
    (`/volume1/docker/spire`, `/volume1/docker/auth-yes`).
  - Never nest one stack's storage or lifecycle under another stack's directory
    structure.