How Do I Build an Azure Network Routetable?

Introduction

This guide aims to walk you through the process of creating a network route table in Azure using Pulumi and associating it with a subnet. A route table is crucial for defining how network traffic is directed within your Azure environment. By the end of this guide, you will have set up a route table with a custom route and linked it to a subnet within a virtual network (VNet).

Key Points

• Route Table: A collection of routes that dictate how network traffic is directed.
• Virtual Network (VNet): A logically isolated network in the Azure cloud environment.
• Subnet Association: Associating a route table with a subnet ensures that its routes are applied to the subnet.

Step-by-Step Process

1. Create a Resource Group: This will hold all the resources related to this setup.
2. Set Up a Virtual Network: Define a virtual network with a specific address space.
3. Define a Subnet: Create a subnet within the virtual network.
4. Create a Route Table: Set up a route table with a custom route, such as directing all traffic (0.0.0.0/0) to the Internet.
5. Associate the Route Table with the Subnet: Link the route table to the subnet to apply its routes.

Code Example

import * as pulumi from "@pulumi/pulumi";
import * as azure from "@pulumi/azure";

const example = new azure.core.ResourceGroup("example", {
    name: "example-resources",
    location: "West US",
});
const exampleVirtualNetwork = new azure.network.VirtualNetwork("example", {
    name: "example-vnet",
    addressSpaces: ["10.0.0.0/16"],
    location: example.location,
    resourceGroupName: example.name,
});
const exampleSubnet = new azure.network.Subnet("example", {
    name: "example-subnet",
    resourceGroupName: example.name,
    virtualNetworkName: exampleVirtualNetwork.name,
    addressPrefixes: ["10.0.1.0/24"],
});
const exampleRouteTable = new azure.network.RouteTable("example", {
    name: "example-route-table",
    location: example.location,
    resourceGroupName: example.name,
    routes: [{
        name: "example-route",
        addressPrefix: "0.0.0.0/0",
        nextHopType: "Internet",
    }],
});
const exampleSubnetRouteTableAssociation = new azure.network.SubnetRouteTableAssociation("example", {
    subnetId: exampleSubnet.id,
    routeTableId: exampleRouteTable.id,
});
export const routeTableId = exampleRouteTable.id;
export const subnetId = exampleSubnet.id;

Explanation of the Code

In this program:

• The azurerm_resource_group block creates a resource group to hold the related resources.
• The azurerm_virtual_network block sets up a virtual network with the specified address space.
• The azurerm_subnet block defines a subnet within the virtual network.
• The azurerm_route_table block creates a route table with a custom route directing all traffic (0.0.0.0/0) to the Internet.
• The azurerm_subnet_route_table_association block associates the route table with the subnet.
• The output blocks provide the IDs of the created route table and subnet for easy reference.

Conclusion

By following this guide, you have successfully created and associated an Azure network route table with a subnet using Pulumi. This setup allows for custom routing of network traffic, which is essential for implementing more complex networking scenarios within your Azure environment. This approach provides a scalable and manageable way to handle network configurations in the cloud.