TargetGroup

A TargetGroup is a logical binding between a Vm and a LoadBalancer. It uses label selectors rather than server IDs — the VM is tagged with a label at creation time, and the load balancer discovers it via the label selector. On AWS this maps to a Target Group, on Hetzner and DigitalOcean to LB target label selectors. GCP does not support TargetGroup — use managed instance groups instead.

Config

Property	Type	Required	Description
name	string	yes	Unique resource name
id	string	no	Explicit ID (auto-generated UUID if omitted)
provider	string	no	Provider label for multi-provider configs
tags	Record<string, string>	no	Arbitrary key-value metadata
port	number	yes	Target port for traffic
label	string	no	Label selector (defaults to kyku-tg=<id>)
vm	Vm | string	yes	Target VM reference
lb	LoadBalancer | string	yes	Parent LoadBalancer reference

Example

import { Vpc, Vm, LoadBalancer, TargetGroup } from '@kykucloud/types'

const myVpc = new Vpc({ name: 'my-vpc', cidr: '10.0.0.0/16', region: 'eu-central' })

const server = new Vm({
  name: 'web',
  instanceType: 'small',
  image: 'ubuntu-24.04',
  network: myVpc,
})

const lb = new LoadBalancer({
  name: 'web-lb',
  lbType: 'application',
  vpc: myVpc,
  listeners: [{ port: 80, protocol: 'http', targets: [] }],
})

const tg = new TargetGroup({
  name: 'web-tg',
  port: 8080,
  vm: server,
  lb: lb,
})

Provider Support

Provider	Supported	Backend
AWS	✅	Target Group (ALB/NLB)
GCP	❌	Not supported — use managed instance groups
Hetzner	✅	LB target with label selector
DigitalOcean	✅	LB target with label selector

Notes

• Label selectors: The label property defaults to kyku-tg=<resource-id>. The VM’s labels are set from its tags at creation time. The LB target uses label_selector: { selector: "kyku-tg=<id>" } to discover the VM.
• GCP: TargetGroup throws UnsupportedFeatureError. Use managed instance groups for GCP traffic distribution.
• Hetzner: Do not set use_private_ip: true when using label selectors — the API returns an error.
• AWS: Target Groups are a separate resource with health check configuration. The LB listener targets array should reference the TargetGroup or use the label selector pattern.
• Circular dependencies: Avoid TargetGroup ↔ LoadBalancer cycles by making only one direction reference the other.