Initial commit: docker-compose-config skill

Add skill for Docker Compose configuration management with:
- Multi-host environment structure with per-hostname overrides
- External volume mount patterns with env variable substitution
- Reverse proxy network configuration for SWAG integration
- Reference docs for examples and network topology

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

SKILL.md

@@ -0,0 +1,168 @@
+---
+name: docker-compose-config
+description: Docker Compose configuration management for multi-host server deployments. Use when creating, modifying, or managing docker-compose.yml files with environment-specific configurations, external volume mounts, and reverse proxy networks. Triggers on tasks involving Docker Compose files, environment overrides, multi-host deployments, or service configuration for self-hosted applications.
+---
+
+# Docker Compose Configuration Management
+
+This skill provides guidance for managing Docker Compose configurations across multiple server environments with per-host overrides.
+
+## Directory Structure
+
+Each project follows this structure:
+
+```
+/docker/config/
+├── <project>/
+│   ├── docker-compose.yml              # Main service definitions
+│   ├── docker-compose.override.yml     # Current host overrides (gitignored)
+│   ├── .env                            # Environment variables (gitignored)
+│   └── environments/
+│       └── <hostname>/                 # Per-host configs
+│           ├── .env
+│           └── docker-compose.override.<hostname>.yml
+```
+
+## Compose File Conventions
+
+### Service Definition Pattern
+
+```yaml
+name: <project-name>
+
+services:
+  <service-name>:
+    container_name: <service_container>
+    image: <registry>/<image>:<version>@sha256:<digest>
+    environment:
+      PUID: ${UID}
+      PGID: ${GID}
+      # Service-specific vars use env substitution
+      VAR_NAME: ${VAR_NAME}
+    volumes:
+      - ${DATA_PATH}:/app/data
+      - /etc/localtime:/etc/localtime:ro
+    ports:
+      - ${SERVICE_PORT:-default}:internal_port
+    restart: unless-stopped
+    networks:
+      - default
+      - reverse_proxy
+
+networks:
+  reverse_proxy:
+    name: reverse_proxy
+    attachable: true
+```
+
+### Key Patterns
+
+1. **Image pinning**: Use SHA256 digests for reproducibility
+   ```yaml
+   image: ghcr.io/org/image:v1.0.0@sha256:abc123...
+   ```
+
+2. **Port defaults**: Always provide defaults for ports
+   ```yaml
+   ports:
+     - ${APP_PORT:-8080}:8080
+   ```
+
+3. **Volume mounts**: Use environment variables for paths
+   ```yaml
+   volumes:
+     - ${UPLOAD_LOCATION}:/usr/src/app/upload
+     - ${DB_DATA_LOCATION}/data:/var/lib/postgresql/data
+   ```
+
+4. **Proxy network**: Services needing reverse proxy access join `reverse_proxy` network
+   ```yaml
+   networks:
+     - default
+     - reverse_proxy
+
+   networks:
+     reverse_proxy:
+       name: reverse_proxy
+       attachable: true
+   ```
+
+## Environment File Conventions
+
+### Structure (.env)
+
+```bash
+# Permissions
+UID=1000
+GID=1000
+
+# Paths
+UPLOAD_LOCATION=/mnt/user/pictures
+DB_DATA_LOCATION=/mnt/user/appdata/<project>
+
+# Ports
+APP_PORT=8080
+
+# Secrets
+DB_PASSWORD=<generated>
+
+# Database
+DB_HOSTNAME=database
+DB_USERNAME=postgres
+DB_DATABASE_NAME=<project>
+```
+
+### Per-Host Variations
+
+- `environments/<hostname>/.env` overrides paths for specific hosts
+- Common overrides: mount paths (`/mnt/user/` vs `/mnt/main/`), ports
+
+## Common Commands
+
+```bash
+# Start a project
+docker compose -f <project>/docker-compose.yml up -d
+
+# Start with host-specific override
+docker compose -f <project>/docker-compose.yml \
+  -f <project>/environments/<host>/docker-compose.override.<host>.yml up -d
+
+# View logs
+docker compose -f <project>/docker-compose.yml logs -f
+
+# Stop services
+docker compose -f <project>/docker-compose.yml down
+```
+
+## Adding a New Host Environment
+
+1. Create `environments/<hostname>/` directory
+2. Copy existing host's `.env` as template
+3. Update paths and port mappings for the host
+4. Create override compose file if device mappings differ
+
+## Service Dependencies
+
+Use `depends_on` with health checks for proper startup order:
+
+```yaml
+depends_on:
+  database:
+    condition: service_healthy
+```
+
+## Healthchecks
+
+```yaml
+healthcheck:
+  test: ["CMD", "curl", "-f", "http://127.0.0.1:8080/"]
+  start_period: 5m
+  interval: 30s
+  timeout: 20s
+  retries: 10
+```
+
+## References
+
+- See [examples.md](references/examples.md) for complete service configurations
+- See [networks.md](references/networks.md) for network topology details