API Management in Azure provides a comprehensive solution for publishing, securing, and managing APIs. Configuring access to APIs involves several key components and steps.
**Subscriptions and Keys**: API Management uses subscription keys as the primary method for controlling API access. When cons…API Management in Azure provides a comprehensive solution for publishing, securing, and managing APIs. Configuring access to APIs involves several key components and steps.
**Subscriptions and Keys**: API Management uses subscription keys as the primary method for controlling API access. When consumers want to call your APIs, they must include a valid subscription key in their HTTP requests. You can create subscriptions at different scopes: all APIs, a single API, or a product level.
**Products**: Products are how you package and publish APIs to developers. A product contains one or more APIs and can be configured as Open (no subscription required) or Protected (subscription required). You can associate policies and access controls at the product level.
**Access Control Policies**: Inbound policies allow you to validate requests before they reach your backend. Common policies include:
- **validate-jwt**: Validates JSON Web Tokens for OAuth 2.0 or OpenID Connect authentication
- **check-header**: Ensures required headers are present
- **rate-limit-by-key**: Throttles requests based on configurable criteria
- **ip-filter**: Restricts access based on IP addresses or ranges
**OAuth 2.0 and OpenID Connect**: You can configure API Management to work with identity providers like Azure AD. This enables token-based authentication where clients obtain tokens from the identity provider and present them when calling APIs.
**Client Certificates**: For enhanced security, you can require clients to present valid certificates for mutual TLS authentication. This is configured through inbound policies that validate certificate properties.
**Developer Portal**: The built-in developer portal allows API consumers to discover APIs, view documentation, and obtain subscription keys. You can customize access and visibility settings for different user groups.
**Configuration Steps**: Use the Azure Portal, ARM templates, Bicep, or Azure CLI to define products, create subscriptions, and apply policies. Testing can be performed through the built-in test console or external tools like Postman.
Configure Access to APIs in API Management
Why It Is Important
API Management is a critical component in modern cloud architectures, serving as the gateway between your backend services and API consumers. Configuring access to APIs ensures that only authorized users and applications can consume your services, protecting sensitive data and preventing unauthorized usage. For the AZ-204 exam, this topic represents a fundamental skill that demonstrates your ability to secure and manage APIs in Azure.
What It Is
Azure API Management (APIM) provides several mechanisms to control access to your APIs:
Subscription Keys - Unique keys that clients must include in requests to access APIs. These can be scoped to all APIs, a single product, or a specific API.
OAuth 2.0 Authorization - Enables token-based authentication using Azure AD or other identity providers.
Client Certificates - Mutual TLS authentication where clients present certificates to prove their identity.
IP Filtering - Restricts access based on client IP addresses or ranges.
Products - Containers for one or more APIs that define access policies and terms of use.
How It Works
Subscription Keys: - APIs require a subscription key by default - Keys are passed via the Ocp-Apim-Subscription-Key header or subscription-key query parameter - Each subscription has primary and secondary keys for rotation
Products: - Open products allow access with no subscription - Protected products require subscription approval - Products can require approval before developers can subscribe
Policies for Access Control: - validate-jwt - Validates JSON Web Tokens - check-header - Enforces presence of HTTP headers - ip-filter - Filters calls from specific IP addresses - rate-limit and quota - Controls usage limits
Certificate Authentication: - Configure in the Inbound processing section - Validate certificate properties like thumbprint, subject, or issuer - Use context.Request.Certificate in policy expressions
Exam Tips: Answering Questions on Configure Access to APIs in API Management
1. Know the subscription key header name - Remember Ocp-Apim-Subscription-Key is the default header for passing subscription keys.
2. Understand product visibility - Products can be Published or Not Published, and can require subscription approval.
3. Policy placement matters - Access control policies typically go in the inbound section of policy definitions.
4. JWT validation scenarios - When questions mention OAuth 2.0 or Azure AD integration, think validate-jwt policy.
5. Certificate validation properties - Know that you can validate thumbprint, issuer, and subject of client certificates.
6. IP filtering syntax - The ip-filter policy uses action attribute with values allow or forbid.
7. Scope hierarchy - Policies can be applied at Global, Product, API, or Operation levels, with more specific scopes overriding broader ones.
8. Named values - Sensitive configuration like certificate thumbprints should be stored in Named Values for reusability.
9. Remember the difference - Subscription keys provide identification, while OAuth 2.0 provides full authentication and authorization.
10. Read scenarios carefully - Determine whether the question asks about authenticating the client to APIM or APIM to the backend service, as these require different configurations.