How Do I Restrict API Access to Specific IP Ranges With Azure API Management Policies?

Introduction

In this guide, we will explore how to implement a policy in Azure API Management to restrict API access to specific IP ranges. Azure API Management policies allow administrators to control API behavior by executing a series of statements on API requests or responses. This capability is crucial for enhancing the security and management of APIs by limiting access to trusted IP addresses.

Step-by-Step Implementation

Below, we will walk through the process of setting up an Azure API Management instance and applying an IP range restriction policy to an API.

Step 1: Define the Azure Provider

First, we set up the Azure provider, which enables interaction with Azure resources.

Step 2: Create a Resource Group

We create a resource group to organize and manage our Azure resources.

Step 3: Set Up API Management Instance

An API Management instance is created within the resource group. This instance will host our API and enforce policies.

Step 4: Define the API

Within the API Management instance, we define an API and specify its basic details, such as name, display name, and protocols.

Step 5: Apply the IP Restriction Policy

We apply a policy to the API that restricts access based on defined IP ranges. The policy uses an IP filter to allow only requests from the specified IP addresses.

Step 6: Output Key Information

Finally, we output the name of the API Management instance and the API ID for reference.

Here is the complete TypeScript program to achieve this:

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

const example = new azure.core.ResourceGroup("example", {
    name: "example-resources",
    location: "West Europe",
});
const exampleService = new azure.apimanagement.Service("example", {
    name: "example-apim",
    location: example.location,
    resourceGroupName: example.name,
    publisherName: "MyCompany",
    publisherEmail: "company@example.com",
    skuName: "Developer_1",
});
const exampleApi = new azure.apimanagement.Api("example", {
    name: "example-api",
    resourceGroupName: example.name,
    apiManagementName: exampleService.name,
    revision: "1",
    displayName: "Example API",
    path: "example",
    protocols: ["https"],
});
const exampleApiPolicy = new azure.apimanagement.ApiPolicy("example", {
    apiName: exampleApi.name,
    apiManagementName: exampleService.name,
    resourceGroupName: example.name,
    xmlContent: `  <policies>
      <inbound>
          <base />
          <check-header header-name="x-forwarded-for" failed-check-httpcode="403">
              <ip-filter action="allow">
                  <address>203.0.113.0/24</address>
                  <address>198.51.100.0/24</address>
              </ip-filter>
          </check-header>
      </inbound>
      <backend>
          <base />
      </backend>
      <outbound>
          <base />
      </outbound>
      <on-error>
          <base />
      </on-error>
  </policies>
`,
});
export const apimName = exampleService.name;
export const apiId = exampleApi.id;

Key Points

• Azure API Management policies can enforce access controls based on IP addresses.
• Creating a resource group helps manage and organize Azure resources.
• The IP filter policy enhances API security by allowing access only from specified IP ranges.

Conclusion

In conclusion, by implementing an IP filter policy in Azure API Management, we enhance the security of our APIs by restricting access to trusted IP ranges. This setup is essential for ensuring that only authorized requests reach our APIs, thereby protecting sensitive data and services.