zoreide/README.md

# ZOREIDE

High Availability daemon to share an IP around N servers.

Zoreide is a daemon service you can use to share an IP among N servers. If the server owning the IP is down,
another one will replace it. Differently than Keepalived, it allows N servers instead of just 2. Perfect for docker-swarm
arrays.

The daemon uses Multicast in order to elect the node which will have the IP configured.

To use it, you need:

- root access to the servers
- a valid multicast IP address in your network. (otherwise you can use the ones in zoreide.json)
- linux servers under the same router.

To compile it , you need:

- golang compiler 1.21 or superior.
- git , to download this repo.
- write "go build" 
- ./zoreide &

Configuration contains:

```
{
  "MulticastConfig": {
    "MIpAddr": "239.0.0.19",
    "MPort": "9898",
  },
  "InterfaceConfig": {
    "ExistingInterface": "eth0",
    "BridgeIpCIDR": "10.0.1.1/24"
  },
  "debug": false
  }
```

Where:

- MIpAddr is the multicast address all the nodes will use to align.Must be the same on all nodes.
- Mport: Multicast port to subscribe. Must be the same on all nodes.
- ~MaxDataGramSize : obsolete, will be removed soon.~ DONE.

- ExistingInterface: the name of your ingress interface (eth0, eno0 , enps18, whatever your system is using. This may be different node by node)
- BridgeIpCidr: the IP address and mask you want to share among servers. 
- wether you want debug logs or not.


# FAQ

- why? Keepalived wasn't enough? 
- VRRP is ok, but it has just two states, active and passive. I want to have as much as nodes as I want.



- why you need more than one server to share the IP?
- because 6 is better than 2 for HA.



- MetalLb under Kubernetes can achieve the same.
- Nobody really needs kubernetes with less than 20 servers. I want a floating , HA IP without this complexity.