Scope and Design Boundaries
What Towlion Is
- A single-server micro-PaaS for deploying small web applications
- GitHub as the control plane — no custom dashboard, CLI, or API
- Docker Compose for container orchestration, Caddy for reverse proxy and automatic TLS
- Fork-to-deploy model — fork a template repo, configure secrets, push to deploy
- Opinionated stack — FastAPI, PostgreSQL, Redis, MinIO, Celery
Design Boundaries
These are intentional constraints, not missing features. They keep the platform simple and predictable.
Infrastructure
| Boundary |
Detail |
| Single server only |
No clustering, no multi-server, no load balancing. Your server is a single point of failure by design. |
| Debian Linux only |
The bootstrap script targets Debian 12. Other distributions are untested. |
| No automated server provisioning |
You create and manage your own server. The bootstrap script configures it, but you are responsible for procurement and access. |
| Fixed resource limits |
Static CPU and memory limits per container. No auto-scaling. |
Deployment
| Boundary |
Detail |
| Brief downtime during deploys |
docker compose up -d --build rebuilds and restarts containers. Caddy returns 502 during the gap. This is typically a few seconds. |
| No built-in test pipeline |
The deploy workflow builds and deploys. It does not run your test suite — add that step yourself if needed. |
| Push-to-main deploys |
No staging environment, no approval gates, no canary or blue-green deploys. Merging to main deploys to production. |
Operations
| Boundary |
Detail |
| No high availability |
Single PostgreSQL, Redis, and MinIO instances. No replication or automatic failover. |
| 5-minute alert granularity |
Health checks run via cron every 5 minutes. This is not real-time monitoring. |
| 7-day backup retention |
Daily pg_dump with 7-day retention. Recovery is manual. There is no disaster recovery plan beyond these backups. |
| No multi-tenant management |
Each fork is independent. There is no shared admin panel or centralized management across apps. |
Technology
| Boundary |
Detail |
| Not Kubernetes |
Docker Compose only. If you need pods, services, ingress controllers, or declarative infrastructure, use Kubernetes. |
| Opinionated stack |
FastAPI + PostgreSQL + Redis + MinIO + Caddy. Other frameworks and databases are outside the supported path. |
| No container registry |
Images are built on the server from source code. There is no registry push/pull step. |
When to Use Something Else
| If you need... |
Consider instead |
| Multi-server / high availability |
Kubernetes, Docker Swarm, Nomad |
| Auto-scaling |
AWS ECS, Cloud Run, Fly.io |
| Managed databases |
AWS RDS, DigitalOcean Managed DB |
| Zero-downtime deploys |
Kubernetes rolling updates, blue-green deploy tooling |
| Large-scale traffic |
Cloud-native platforms with load balancers |
| Non-Python backends |
Dokku, Coolify, CapRover |
Sweet Spot
Towlion is built for indie developers, small SaaS products, personal tools, hobby projects, and AI-generated applications. If your app serves a handful of users, runs comfortably on a single server, and you want to own your infrastructure without managing Kubernetes, Towlion is a good fit.