Load Balancer

miniblue emulates Azure Load Balancer via ARM endpoints. Supports frontend IP configurations, backend address pools, load balancing rules, probes, inbound NAT rules and outbound rules.

API endpoints

Method	Path	Description
PUT	/subscriptions/{sub}/resourceGroups/{rg}/providers/Microsoft.Network/loadBalancers/{name}	Create or update
GET	/subscriptions/{sub}/resourceGroups/{rg}/providers/Microsoft.Network/loadBalancers/{name}	Get
DELETE	/subscriptions/{sub}/resourceGroups/{rg}/providers/Microsoft.Network/loadBalancers/{name}	Delete
GET	/subscriptions/{sub}/resourceGroups/{rg}/providers/Microsoft.Network/loadBalancers	List

Create a load balancer

curl -X PUT "http://localhost:4566/subscriptions/sub1/resourceGroups/myRG/providers/Microsoft.Network/loadBalancers/my-lb?api-version=2023-09-01" \
  -H "Content-Type: application/json" \
  -d '{
    "location": "eastus",
    "sku": {"name": "Standard", "tier": "Regional"},
    "properties": {
      "frontendIPConfigurations": [{"name": "frontend", "properties": {"publicIPAddress": {"id": "/subscriptions/sub1/resourceGroups/myRG/providers/Microsoft.Network/publicIPAddresses/my-pip"}}}],
      "backendAddressPools": [{"name": "backend-pool"}],
      "probes": [{"name": "http-probe", "properties": {"protocol": "Tcp", "port": 80}}],
      "loadBalancingRules": [{"name": "http-rule", "properties": {"protocol": "Tcp", "frontendPort": 80, "backendPort": 80}}]
    }
  }'

Terraform

resource "azurerm_lb" "example" {
  name                = "example-lb"
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
  sku                 = "Standard"

  frontend_ip_configuration {
    name                 = "frontend"
    public_ip_address_id = azurerm_public_ip.example.id
  }
}

Limitations

• No actual traffic routing or health checking
• Backend pool members are stored but not validated
• No cross-region load balancer support