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* Define a dual-stack virtual network with both IPv4 and IPv6 private
address space. Change `host_cidr` variable (string) to a `network_cidr`
variable (object) with "ipv4" and "ipv6" fields that list CIDR strings.
* Define dual-stack controller and worker subnets. Disable Azure
default outbound access (a deprecated fallback mechanism)
* Enable dual-stack load balancing to Kubernetes Ingress by adding
a public IPv6 frontend IP and LB rule to the load balancer.
* Enable worker outbound IPv6 connectivity through load balancer
SNAT by adding an IPv6 frontend IP and outbound rule
* Configure controller nodes with a public IPv6 address to provide
direct outbound IPv6 connectivity
* Add an IPv6 worker backend pool. Azure requires separate IPv4 and
IPv6 backend pools, though the health probe can be shared
* Extend network security group rules for IPv6 source/destinations
Checklist:
Access to controller and worker nodes via IPv6 addresses:
* SSH access to controller nodes via public IPv6 address
* SSH access to worker nodes via (private) IPv6 address (via
controller)
Outbound IPv6 connectivity from controller and worker nodes:
```
nc -6 -zv ipv6.google.com 80
Ncat: Version 7.94 ( https://nmap.org/ncat )
Ncat: Connected to [2607:f8b0:4001:c16::66]:80.
Ncat: 0 bytes sent, 0 bytes received in 0.02 seconds.
```
Serve Ingress traffic via IPv4 or IPv6 just requires setting
up A and AAAA records and running the ingress controller with
`hostNetwork: true` since, hostPort only forwards IPv4 traffic
2.6 KiB
Azure
Load Balancing
kube-apiserver
A load balancer distributes IPv4 TCP/6443 traffic across a backend address pool of controllers with a healthy kube-apiserver. Clusters with multiple controllers use an availability set with 2 fault domains to tolerate hardware failures within Azure.
HTTP/HTTPS Ingress
An Azure Load Balancer distributes IPv4/IPv6 TCP/80 and TCP/443 traffic across backend address pools of workers with a healthy Ingress controller.
The load balancer addresses are output as ingress_static_ipv4 and ingress_static_ipv6 for use in DNS A and AAAA records. See Ingress on Azure.
TCP/UDP Services
Load balance TCP/UDP applications by adding rules to the Azure LB (output). A rule may map different ports (e.g. 3333 external, 30333 internal).
# Forward traffic to the worker backend address pool
resource "azurerm_lb_rule" "some-app-tcp" {
name = "some-app-tcp"
resource_group_name = module.ramius.resource_group_name
loadbalancer_id = module.ramius.loadbalancer_id
frontend_ip_configuration_name = "ingress-ipv4"
protocol = "Tcp"
frontend_port = 3333
backend_port = 30333
backend_address_pool_ids = module.ramius.backend_address_pool_ids.ipv4
probe_id = azurerm_lb_probe.some-app.id
}
# Health check some-app
resource "azurerm_lb_probe" "some-app" {
name = "some-app"
resource_group_name = module.ramius.resource_group_name
loadbalancer_id = module.ramius.loadbalancer_id
protocol = "Tcp"
port = 30333
}
Firewalls
Add firewall rules to the worker security group.
resource "azurerm_network_security_rule" "some-app" {
name = "some-app"
resource_group_name = module.ramius.resource_group_name
network_security_group_name = module.ramius.worker_security_group_name
priority = "3001"
access = "Allow"
direction = "Inbound"
protocol = "Tcp"
source_port_range = "*"
destination_port_range = "30333"
source_address_prefix = "*"
destination_address_prefixes = module.ramius.worker_address_prefixes.ipv4
}
IPv6
Azure does not provide public IPv6 addresses at the standard SKU.
| IPv6 Feature | Supported |
|---|---|
| Node IPv6 address | Yes |
| Node Outbound IPv6 | Yes |
| Kubernetes Ingress IPv6 | Yes |