Aeolus

Ancient Greek: Αἴολος, Aiolos - In Greek mythology, Aeolus was the ruler of the winds.

This is a proof-of-concept (PoC) implementation of Unimog.

Description:

Note: Since this is a PoC, to make it simpler, Aeolus follows a slightly different approach to transfer packets between servers compared to Unimog.

Setup consideration:

For the purpose of testing Aeolus and to simplify the architecture, I created two Linux virtual machines, and manually added a matching IP address from within the machines. And in addition to that IP, each machine has its own unique IP which is used for health check. However, this is not a recommended setup because the address resolution protocol (ARP) will make all packets arrive on the same machine before being transfered or consumed, causing a single entry point.

Transfering packets between servers:

Since all servers share the same IP, I opted to transfer packets between servers by modifying the destination MAC address of the packet rather than encapsulating it with the generic UDP encapsulation method.

Usage:

Usage: aeolus [OPTIONS]

Options:
      --config <FILE>   Path to Aeolus configuration file [default: aeolus.yaml]
  -h, --help            Print help

Configuration File:

Options:

• servers: A list of dictionaries with ip and mac keys.
• ports: A list of u16 values. [Optional - Defaults to [80]]
• logfile: Path to the log file. [Optional - Defaults to /var/log/aeolus.log]
• iface: The name of the interface to attach the xdp app to. [Optional - Defaults to wlp1s0]
• health_interval: A u8 value representing how often should the health checker run. (In seconds) [Optional - Defaults to 10]

Sample aeolus.yaml file:

servers:
  - mac: 52:54:00:94:df:40
    ip: 192.168.122.246

  - mac: 52:54:00:61:be:9e
    ip: 192.168.122.72

ports: 
  - 80
  - 443

logfile: ./aeolus.log
iface: enp3s0
health_interval: 30

The file configures Aeolus to only balance ports 80 and 443 between two servers, logs everything in ./aeolus.log, and attaches the xdp application to interface enp3s0.