Docker Administration for Small Networks

Managing a small fleet of 6-10 containers across 2-3 hosts represents a "Goldilocks" zone in system administration: too complex for manual ad-hoc commands, but small enough that heavy orchestrators like Kubernetes introduce more problems (overhead, complexity, resource drain) than they solve.

This guide outlines a tiered approach to Docker administration, prioritizing simplicity, data integrity, and a "clean" production environment.

Tier 1: The "Invisible" Minimalist (SSH + Docker Compose)

For users who want zero "middleman" overhead and full control over every configuration byte, the combination of SSH and Docker Compose remains the gold standard.

Core Practices

• Version Control Everything: Never run docker run directly. Keep every service in a docker-compose.yml file stored in a private Git repository.
• Infrastructure as Code (Lite): Use a consistent directory structure on your hosts (e.g., /opt/stacks/app-name/).
• The "One-File" Rule: Keep environment variables in .env files sibling to your compose files.

Automation via SSH

You can manage remote hosts without logging in by using the Docker Context feature:

# Register a remote host
docker context create remote-host --docker "host=ssh://user@host-ip"
# Switch to it
docker context use remote-host
# Run commands as if local
docker compose up -d

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Tier 2: The Modern PaaS (All-in-One Management)

If you prefer a "Heroku-like" experience where SSL, domain routing, and deployments are handled automatically, several open-source tools have matured to solve this specifically for small networks.

1. Coolify (The Feature King)

Coolify is arguably the most advanced self-hosted PaaS. It manages your servers, handles Git-push-to-deploy, and automates database backups.

• Best For: Developers who want a professional cloud experience (Vercel/Railway) on their own hardware.
• Resource Note: Requires at least 2GB of RAM on the management host.

2. Dockge (The Compose Specialist)

Created by the developer of Uptime Kuma, Dockge provides a beautiful, reactive UI for managing your Compose stacks. Unlike Portainer, it doesn't try to abstract Docker; it just helps you manage the .yaml files.

• Best For: Users who love Docker Compose but want a visual dashboard to see logs and edit files without an editor.

3. CapRover (The Rock Solid)

An older, extremely stable PaaS that uses Docker Swarm under the hood for "one-click" apps and automatic Nginx/SSL setup.

• Best For: Set-and-forget stability.

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Tier 3: Multi-Host Strategy (The 3-Host Network)

When moving beyond a single host, you must solve for Networking and Storage.

1. Networking: Docker Swarm

For 2-3 hosts, Docker Swarm is significantly easier than Kubernetes. It is built into Docker and uses an "overlay network" that allows containers on Host A to talk to Host B as if they were local.

• Command: docker swarm init on Host A, docker swarm join on Host B/C.

2. Reverse Proxy: Traefik or Nginx Proxy Manager

• Traefik: The "native" choice. It automatically detects new containers and generates SSL certificates based on Docker labels.
• Nginx Proxy Manager: Provides a simple web UI to map domains to container IPs.

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Essential Production Practices

Regardless of the tool you choose, these three rules prevent "screwing things up":

1. The 3-2-1 Backup Rule

Containers are ephemeral; volumes are not.

• Tool: Use Restic or BorgBackup.
• Strategy: Backup the /var/lib/docker/volumes/ (or your bind mounts) and your .env/docker-compose.yml files daily. Push encrypted copies to an offsite S3 bucket (Backblaze B2 or MinIO).

2. Automated Updates (with Caution)

Use Watchtower to keep your images fresh.

• Pro-Tip: Use the :version-tag (e.g., postgres:15) instead of :latest to ensure a minor update doesn't break your database schema unexpectedly.

3. Log Hygiene

By default, Docker logs can grow indefinitely. Limit them in your /etc/docker/daemon.json:

{
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "10m",
    "max-file": "3"
  }
}

Summary Comparison

Goal	Recommended Stack
Max Control / Zero Bloat	SSH + Git + Docker Contexts
Easy Web Management	Dockge + Nginx Proxy Manager
Full Private Cloud (GitOps)	Coolify
High Stability / Multi-Host	Docker Swarm + CapRover