Proxmox Service Discovery

This project implements a DNS-based service discovery mechanism using Go for Proxmox Cluster. The service retrieves virtual machine (VM) information from a Proxmox API and automatically generates DNS A records based on VM names and tags. These records are updated periodically and can be used to discover services in a dynamic environment.

Features

• Retrieves VM information (name, tags, IP) from the Proxmox API.
• Dynamically generates DNS A records based on VM names and tags.
• Updates DNS records every minute, ensuring the latest VM state.
• Uses a custom DNS suffix for generated records.
• Supports service discovery by allowing other services to resolve VMs by name or tag using DNS.

How It Works

1. The service queries the Proxmox API to fetch a list of VMs for each node.
2. For each VM, the service retrieves the VM's configuration, including:
   • Node name and IP Address (DISCOVERY_NODE_CIDR)
   • VM name (name) and IP address (ipconfig0)
   • VM tags (tags), which are separated by semicolons. (DISCOVERY_VM_TAGS)
3. The service creates DNS A records for each Node in Cluster and VM based on its name and tags, appending a configurable DNS suffix to each record.
4. These records are updated in memory every 60 seconds to reflect changes in the Proxmox environment.
5. The service runs a DNS server on port 2053 that resolves DNS queries based on the stored records.

Requirements

• Go 1.18+
• A running Proxmox instance with API access

Installation

You can use the way you want to start service. For example, using systemd

1. Download last release version from github
2. Copy proxmox-service-discovery.service.example to /etc/systemd/system/proxmox-service-discovery.service and change values
3. Copy .env.example file /path/to/your/dns-service-discovery/.env and fill values.
4. sudo systemctl daemon-reload
5. sudo systemctl enable proxmox-service-discovery
6. sudo systemctl start proxmox-service-discovery
7. sudo systemctl status proxmox-service-discovery

Development

1. Clone the repository:

   git clone https://github.com/nrukavkov/proxmox-service-discovery.git
   cd proxmox-service-discovery

2. Install dependencies:

   go mod tidy

3. Create a .env file to configure the service:

   touch .env

4. In the .env file, add the following environment variables:

   PROXMOX_URL=https://your-proxmox-api-url
   PVE_API_TOKEN=your-proxmox-api-token
   DNS_SUFFIX=.proxmox.example.com
   DNS_LISTEN_PORT=53 # use 2053 for local testing
   DNS_REFRESH_SECONDS=60 # how ofter go to proxmox api
   DISCOVERY_VM_TAGS=true # if true proxmox-service-discovery records will be filled also with tags
   DISCOVERY_NODE_CIDR=192.168.0.0/24
   

5. Build and run the Go application:

   go build -o proxmox-service-discovery
   ./proxmox-service-discovery

The DNS server will start on port 2053 and will update DNS records every minute.

To test the DNS queries, you can use dig or any other DNS client:

dig @localhost -p 2053 vm01.proxmox.example.com

License

This project is licensed under the MIT License. See the LICENSE file for details.