Configuring Virtual Network Firewall Rules for Azure SQL

Question

Pulumi · Accepted Answer

To configure virtual network firewall rules for an Azure SQL server using Pulumi, you will typically perform a series of steps that include creating an Azure SQL server, setting up the firewall rules, and potentially linking the server to a specific virtual network subnet if necessary. We'll go through each step in detail and explain how to do this using Pulumi with Python.

Here's a summary of the steps we're going to take in the Pulumi program:

1. **Create an Azure SQL Server**: This will be the database server that your databases will reside in.
2. **Configure a Firewall Rule**: To control the network access to the SQL Server, you'll configure firewall rules that specify which IP addresses are allowed to communicate with the server.
3. **Create a Virtual Network Rule**: (Optional) If you want to restrict access to the Azure SQL Server from within a given virtual network, you can create a virtual network rule that links the SQL server to a subnet within a virtual network.

Now let's start writing the program that accomplishes these steps.

```python
import pulumi
import pulumi_azure_native as azure_native

# Step 1: Create an Azure SQL Server
sql_server = azure_native.sql.Server("my-sql-server",
    resource_group_name="my-resource-group",
    location="eastus",
    server_name="my-server-name",
    administrator_login="myadmin",
    administrator_login_password="mystrongpassword!",
    version="12.0") # You can use "12.0" for V12 or "2.0" for V2.

# Step 2: Configure a Firewall Rule
# This firewall rule allows access from a specific IP range
firewall_rule = azure_native.sql.FirewallRule("my-firewall-rule",
    resource_group_name="my-resource-group",
    server_name=sql_server.name,
    start_ip_address="0.0.0.0", # Start of the IP range
    end_ip_address="255.255.255.255") # End of the IP range

# Step 3: (Optional) Create a Virtual Network Rule
# Before executing this, create or obtain an existing subnet's resource ID
my_virtual_network_subnet_id = "/subscriptions/{subscription-id}/resourceGroups/{resource-group-name}/providers/Microsoft.Network/virtualNetworks/{vnet-name}/subnets/{subnet-name}"

virtual_network_rule = azure_native.sql.VirtualNetworkRule("my-virtual-network-rule",
    resource_group_name="my-resource-group",
    server_name=sql_server.name,
    virtual_network_subnet_id=my_virtual_network_subnet_id, # The subnet id that you want to link to the SQL server.
    ignore_missing_vnet_service_endpoint=False) # If set to True, the rule will ignore the missing Service Endpoints and proceed with the rule creation.

# Export the SQL Server name and additional details if needed
pulumi.export('sql_server_name', sql_server.name)
pulumi.export('firewall_rule_name', firewall_rule.name)
pulumi.export('virtual_network_rule_name', virtual_network_rule.name)
```

Let's go through this program:

- We begin by importing the necessary Pulumi modules.
- We define a new SQL server with necessary parameters, including the admin login and password, on Azure using the `azure_native.sql.Server` class.
- Then, we define a firewall rule using the `azure_native.sql.FirewallRule` class, which enables SQL server access between the specified IP range. 
- The optional step includes creating a virtual network rule with `azure_native.sql.VirtualNetworkRule` to link the SQL server to a specific subnet. Make sure to set your subnet's resource ID explicitly in the variable `my_virtual_network_subnet_id`.
- We use `pulumi.export` to output the names of the resources we created for easy access and reference.

You will need to replace placeholders like `"my-resource-group"` and `"my-server-name"` with your actual resource group name and desired SQL server name. Make sure to set the administrator login password securely. The virtual network subnet ID needs to be the resource ID of an existing subnet you have set up in Azure.

**Important Note:** The firewall rule IP range used here '0.0.0.0' to '255.255.255.255' is broad and not recommended for production environments. It effectively allows traffic from any IP address. You should restrict this range to only known IPs that require access to the SQL server for security purposes.

To apply this Pulumi program, you must have an Azure account set up with the Pulumi Azure Native provider configured, which typically includes setting environment variables for authentication.

This program is a foundational step to create and configure a secure Azure SQL database server. You can expand this further to include actual databases, manage users, and implement other Azure services as needed.