kubespray/docs/metallb.md

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# MetalLB
MetalLB hooks into your Kubernetes cluster, and provides a network load-balancer implementation.
It allows you to create Kubernetes services of type "LoadBalancer" in clusters that don't run on a cloud provider, and thus cannot simply hook into 3rd party products to provide load-balancers.
The default operationg mode of MetalLB is in ["Layer2"](https://metallb.universe.tf/concepts/layer2/) but it can also operate in ["BGP"](https://metallb.universe.tf/concepts/bgp/) mode.
## Prerequisites
You have to configure arp_ignore and arp_announce to avoid answering ARP queries from kube-ipvs0 interface for MetalLB to work.
```yaml
kube_proxy_strict_arp: true
```
## Install
You have to explicitly enable the MetalLB extension and set an IP address range from which to allocate LoadBalancer IPs.
```yaml
metallb_enabled: true
metallb_speaker_enabled: true
metallb_avoid_buggy_ips: true
metallb_ip_range:
- 10.5.0.0/16
```
By default only the MetalLB BGP speaker is allowed to run on control plane nodes. If you have a single node cluster or a cluster where control plane are also worker nodes you may need to enable tolerations for the MetalLB controller:
```yaml
metallb_controller_tolerations:
- key: "node-role.kubernetes.io/master"
operator: "Equal"
value: ""
effect: "NoSchedule"
- key: "node-role.kubernetes.io/control-plane"
operator: "Equal"
value: ""
effect: "NoSchedule"
```
## BGP Mode
When operating in BGP Mode MetalLB needs to have defined upstream peers:
```yaml
metallb_protocol: bgp
metallb_ip_range:
- 10.5.0.0/16
metallb_peers:
- peer_address: 192.0.2.1
peer_asn: 64512
my_asn: 4200000000
- peer_address: 192.0.2.2
peer_asn: 64513
my_asn: 4200000000
```
Some upstream BGP peers may require password authentication:
```yaml
metallb_protocol: bgp
metallb_ip_range:
- 10.5.0.0/16
metallb_peers:
- peer_address: 192.0.2.1
peer_asn: 64512
my_asn: 4200000000
password: "changeme"
```
When using calico >= 3.18 you can replace MetalLB speaker by calico Service LoadBalancer IP advertisement.
See [calico service IPs advertisement documentation](https://docs.projectcalico.org/archive/v3.18/networking/advertise-service-ips#advertise-service-load-balancer-ip-addresses).
In this scenarion you should disable the MetalLB speaker and configure the `calico_advertise_service_loadbalancer_ips` to match your `metallb_ip_range`
```yaml
metallb_speaker_enabled: false
metallb_avoid_buggy_ips: true
metallb_ip_range:
- 10.5.0.0/16
calico_advertise_service_loadbalancer_ips: "{{ metallb_ip_range }}"
```
If you have additional loadbalancer IP pool in `metallb_additional_address_pools` , ensure to add them to the list.
```yaml
metallb_speaker_enabled: false
metallb_ip_range:
- 10.5.0.0/16
metallb_additional_address_pools:
kube_service_pool_1:
ip_range:
- 10.6.0.0/16
protocol: "bgp"
auto_assign: false
avoid_buggy_ips: true
kube_service_pool_2:
ip_range:
- 10.10.0.0/16
protocol: "bgp"
auto_assign: false
avoid_buggy_ips: true
calico_advertise_service_loadbalancer_ips:
- 10.5.0.0/16
- 10.6.0.0/16
- 10.10.0.0/16
```