How can Envoy enforce authorization policies?

Envoy can enforce authorization policies by integrating with external authorization services. This approach allows Envoy to delegate the decision-making process about whether requests should be allowed or denied to an external service that specializes in authorization. By utilizing an external service, Envoy can enforce complex policies that take into account various factors such as user identity, resource types, and other contextual information.

This integration is typically achieved through the use of Envoy filters, which can be configured to communicate with an external authorization server. When a request is received, Envoy sends the relevant information to this external service, which evaluates the request against its policy rules and returns a decision to Envoy. This results in a flexible and powerful authorization mechanism that can adapt to changing requirements without requiring changes to the service code itself.

In contrast, directly modifying service code would be less flexible and could lead to inconsistencies and maintenance challenges. Automatically blocking unauthorized requests could occur based on static rules but may not accommodate nuanced or dynamic authorization needs. Enabling logging for all user requests, while useful for auditing and monitoring, does not enforce policies by itself; it simply records events without determining access rights.