name: docker
description: Docker Compose, container management, and infrastructure patterns. Load when working with Dockerfile, docker-compose.yml, or deployment tasks.
Docker
Commands
| Task |
Command |
| Start dev |
docker-compose -f docker/docker-compose.dev.yml up -d |
| Start prod |
docker-compose up -d |
| View logs |
docker-compose logs -f [service] |
| Rebuild |
docker-compose build --no-cache |
| Full reset |
docker-compose down && docker-compose up -d --build |
| Enter container |
docker exec -it nop-backend bash |
| Check health |
docker-compose ps |
| Config test |
docker-compose config |
Gotchas
| Category |
Pattern |
Solution |
| Build |
Changes not visible |
Use --no-cache flag |
| Build |
Container old code |
Use --build --force-recreate |
| Network |
Bridge uses gateway IP |
Use different IP for containers |
| Ports |
Wrong service on port |
Verify port mappings (8000=Portainer, 12000=NOP) |
| Config |
Invalid YAML |
Run docker-compose config first |
| Volumes |
Data not persisting |
Check volume mounts in compose file |
Rules
| Rule |
Requirement |
| Config test |
Run docker-compose config before apply |
| Health checks |
Define health checks for all services |
| Resource limits |
Set memory/CPU limits |
| Secrets |
Use environment variables, not hardcoded |
| Rollback |
Document rollback plan |
Patterns
# Pattern 1: Health check
services:
backend:
healthcheck:
test: ["CMD", "curl", "-f", "http://localhost:8000/health"]
interval: 30s
timeout: 10s
retries: 3
# Pattern 2: Resource limits
services:
backend:
deploy:
resources:
limits:
cpus: '0.50'
memory: 512M
# Pattern 3: Environment from file
services:
backend:
env_file:
- .env
Pre-Change Checklist
Rollback Plan Template
## Rollback Plan
### Changes Made
1. [Change 1]
2. [Change 2]
### Rollback Steps
1. `docker-compose down`
2. `git checkout [previous-commit] -- [files]`
3. `docker-compose up -d --build`
### Verification
- [ ] Services healthy
- [ ] Application accessible
- [ ] Logs show no errors
By