Mapping virtual machine IP addresses with Azure Private DNS A records

Question

Pulumi · Accepted Answer

To map virtual machine IP addresses with Azure Private DNS A records, you'll need to create a few resources:

1. A resource group to contain all resources.
2. A virtual network and subnet where the virtual machine will be placed.
3. A virtual machine, which will be assigned a private IP address.
4. A private DNS zone to contain your DNS records.
5. An A record within the private DNS zone that points to the private IP of the virtual machine.

Let's go through this step-by-step:

### Import Pulumi Azure Native packages

First, you need to import the necessary Pulumi and Azure Native packages:

```typescript
import * as pulumi from "@pulumi/pulumi";
import * as azure from "@pulumi/azure-native";
```

### Create a Resource Group
You will need to create an Azure Resource Group, a container that holds related resources for an Azure solution.

### Create a Virtual Network and Subnet

Next, you must create a virtual network and subnet for your virtual machine. Azure virtual networks (VNets) enable Azure resources such as VMs to securely communicate with each other, the internet, and on-premises networks.

### Create a Virtual Machine

You will create a virtual machine within the virtual network. This virtual machine will be assigned a private IP address automatically or you can specify one.

### Create a Private DNS Zone

A private DNS zone is used to host the DNS records for your internal network. The virtual network will need to be linked to the DNS zone to resolve the DNS names.

### Create an A Record

Finally, you will create an A record in the private DNS zone. An A record maps a domain name to an IP address, and in this case, it will map a domain name to the private IP of your virtual machine.

Let's put this together in code:

```typescript
import * as pulumi from "@pulumi/pulumi";
import * as azure from "@pulumi/azure-native";

// Create a new resource group
const resourceGroup = new azure.resources.ResourceGroup("myResourceGroup");

// Create a new virtual network and a subnet
const virtualNetwork = new azure.network.VirtualNetwork("myVnet", {
    resourceGroupName: resourceGroup.name,
    addressSpace: {
        addressPrefixes: ["10.0.0.0/16"],
    },
});

const subnet = new azure.network.Subnet("mySubnet", {
    resourceGroupName: resourceGroup.name,
    virtualNetworkName: virtualNetwork.name,
    addressPrefix: "10.0.1.0/24",
});

// Create a network interface for the VM
const networkInterface = new azure.network.NetworkInterface("myNic", {
    resourceGroupName: resourceGroup.name,
    ipConfigurations: [{
        name: "myNicConfiguration",
        subnet: {
            id: subnet.id,
        },
        privateIpAddressAllocation: "Dynamic",
    }],
});

// Create a VM
const virtualMachine = new azure.compute.VirtualMachine("myVm", {
    resourceGroupName: resourceGroup.name,
    networkInterfaceIds: [networkInterface.id],
    hardwareProfile: {
        vmSize: azure.compute.VirtualMachineSizeTypes.Standard_B2s,
    },
    storageProfile: {
        imageReference: {
            publisher: "Canonical",
            offer: "UbuntuServer",
            sku: "16.04-LTS",
            version: "latest",
        },
        osDisk: {
            createOption: "FromImage",
            name: "myOsDisk",
        },
    },
    osProfile: {
        computerName: "myvm",
        adminUsername: "azureuser",
        adminPassword: "Password1234!",
    },
    location: resourceGroup.location,
});

// Create a private DNS zone
const privateDnsZone = new azure.network.PrivateZone("myPrivateDnsZone", {
    resourceGroupName: resourceGroup.name,
    location: "Global",
    privateZoneName: "mydomain.local",
});

// Link the virtual network to the DNS zone
const vnetLink = new azure.network.VirtualNetworkLink("myVnetLink", {
    resourceGroupName: resourceGroup.name,
    privateZoneName: privateDnsZone.name,
    virtualNetwork: {
        id: virtualNetwork.id
    },
    registrationEnabled: true,
});

// Create an A record pointing to the VM's private IP
const aRecord = new azure.network.RecordSet("myARecord", {
    resourceGroupName: resourceGroup.name,
    zoneName: privateDnsZone.name,
    type: "A",
    ttl: 300,
    aRecords: [{
        ipv4Address: networkInterface.apply(nic => nic.ipConfigurations[0].privateIPAddress),
    }],
});

// Export the domain name and IP address
export const vmDomainName = pulumi.concat("myvm", ".", privateDnsZone.name);
export const vmPrivateIp = aRecord.aRecords.apply(aRecords => aRecords[0].ipv4Address);

```

In the code above:

- We define a resource group named `myResourceGroup`.
- We create a virtual network `myVnet` with a subnet `mySubnet`.
- A network interface `myNic` that the virtual machine will use is created.
- We define a virtual machine `myVm` with the necessary profiles for its size, storage, and OS. Its network interface is linked to the one we created earlier.
- A private DNS zone `myPrivateDnsZone` is created with the name `mydomain.local`.
- We link the virtual network to the DNS zone using `myVnetLink`, which allows the virtual network to resolve DNS names in the `mydomain.local` zone.
- An A record `myARecord` is created to point to the VM's private IP address.
- We export the domain name and private IP address of the VM, which can be used outside of Pulumi to connect to the VM or for other configuration.

Make sure to replace the placeholders and sensitive information like `adminPassword` with your own values. This code will provide you with a running VM on Azure and the DNS setup to allow for private domain name resolution.