This project sets up a Prometheus instance with Tailscale VPN integration using Docker Compose. It creates a secure, private network connection for your Prometheus instance using Tailscale.

Prerequisites

Docker and Docker Compose installed on your system
A Tailscale account and auth key (get one from https://login.tailscale.com/admin/authkeys)
Basic understanding of Docker and networking concepts

Project Structure

ts-prometheus/
├── docker-compose.yml
├── tailscale/
│   ├── tailscale-data/             # Persistent Tailscale state
│   └── config/                     # Tailscale configuration files
└── prometheus/
    │   └── etc/
    │       └── prometheus/         # Prometheus configuration files
    └── data/                       # Prometheus data

Setup Instructions

Clone the Repository

git clone https://gitea.damconsulting.llc/DAM/ts-prometheus
cd ts-prometheus

Create Required Directories

mkdir -p tailscale/tailscale-data prometheus/data

Configure Tailscale
- Replace {{YOUR_TAILSCALE_AUTHKEY}} in the docker-compose.yml with your actual Tailscale auth key
- Optionally, update the file in tailscale/config/serve.json if you need specific Tailscale serve configurations
  - CAUTION: Changing "${TS_CERT_DOMAIN}:443": false to true will expose the service to the internet
Configure Prometheus /prometheus/etc/prometheus/prometheus.yml
- See https://prometheus.io/docs/prometheus/latest/configuration/configuration/ for configuration options
Start the Services
```
docker compose up -d
```
Wait for Certificate to propagate [~2m]
Login

Services

prometheus-ts (Tailscale)

Runs Tailscale VPN client
Image: tailscale/tailscale:latest
Container name: prometheus-ts
Hostname: prometheus
Requires NET_ADMIN and SYS_MODULE capabilities
Persists state in ./tailscale/tailscale-data
Uses configuration from ./tailscale/config

prometheus

Depends on prometheus-ts service

Usage

After starting the services your service should be available via tailnet at https://prometheus.{{YOUR_TAILNET_DOMAIN}}.ts.net ie https://prometheus.tail12345.ts.net/
To manually get the Tailscale IP/hostname of your container:
```
docker logs prometheus-ts
```
Look for the Tailscale IP address in the logs.

Optional Features

Uncomment and adjust the ports mapping if you need direct access (without Tailscale):
```
ports:
- 9000:9000
```
Stopping the Services
```
docker compose down
```

Troubleshooting

Check container logs:

docker logs prometheus-ts
docker logs prometheus

Ensure your Tailscale auth key is valid and not expired
Verify the configuration files have proper permissions
Make sure required directories exist before starting

Notes

The Prometheus service uses the Tailscale service's network stack via network_mode: service:prometheus-ts
Direct port mapping is disabled by default as Tailscale handles the networking
Services restart automatically unless explicitly stopped
For more information:
- Tailscale documentation: https://tailscale.com/kb/
- Prometheus documentation: https://prometheus.io/docs/introduction/overview/
- Prometheus repository: https://github.com/prometheus/prometheus