Securing your microservices using Istio – Implementing Traffic Management, Security, and Observability with Istio

Running microservices in production offers numerous advantages, such as independent scalability, enhanced agility, reduced scope of change, frequent deployments, and reusability. However, they also introduce unique challenges, particularly in terms of security.

In a monolithic architecture, the security focus revolves around safeguarding a single application. However, in a typical enterprise-grade microservices application, hundreds of microservices may

need to interact securely with each other. Kubernetes serves as an excellent platform for hosting and orchestrating microservices. Nevertheless, the default communication between microservices is insecure, as they typically use plaintext HTTP. This maynot meet your security requirements. To apply the same security principles to microservices as you would to a traditional enterprise monolith, you must ensure the following:

• Encrypted communications: All interactions between microservices must be encrypted to prevent potential man-in-the-middle attacks

• Access control: Access control mechanisms need to be in place to ensure that only authorized microservices can interface with each other

• Telemetry and audit logging: Capturing, logging, and auditing telemetry data is crucial to understanding traffic behavior and proactively detecting intrusions

Istio simplifies addressing these security concerns and provides these essential security features out of the box. With Istio, you can enforce strong identity and access management, mutual TLS and encryption, authentication and authorization, and comprehensive audit logging – all within aunified control plane. This means you can establishrobust security practices for your microservices, promoting the safety and reliability of your applications in a dynamic and distributed environment.

In the context of Istio, you should be aware that it automatically injects sidecar proxies into your pods and modifies the IP tables of your Kubernetes cluster to ensure that all connections occur through these proxies. This setup is designed to enforce TLS encryption by default, enhancing the security of your microservices without requiring specific configurations. The communication between these envoy proxies within the service mesh is automatically secured through TLS.

While the default setup offers a foundational level of security and effectively prevents man-in-the-middle attacks, it’s advisable to further bolster the security of your microservices by applying specific policies. Before delving into the detailed features, having a high-level understanding of how security functions in Istio is beneficial.

Istio incorporates the following key components for enforcing security:

• Certificate authority (CA): Thiscomponent manages keys and certificates, ensuring secure and authenticated communication within the service mesh.

• Configuration API Server: The Configuration API Server distributes authentication policies, authorization policies, and secure naming information to the envoy proxies. These policies define how services can authenticate and authorize each other and manage secure communication.

• Sidecar proxies: Sidecar proxies, deployed alongside your microservices, are crucial in enforcing security policies. They act as policy enforcement points, implementing the policies supplied to them.

• Envoy proxy extensions: These extensions enable the collection of telemetry data and auditing, providing insights into traffic behavior and helping to identify and mitigate security issues.

With these components working in concert, Istio ensures a robust security framework for your microservices, which can be further fine-tuned by defining and enforcing specific security policies tailored to your application’s needs.

As our application currently runs on HTTP, it would be a great idea to implement TLS in our Blog App and expose it over HTTPS. Let’s start by creating a secure ingress gateway for this.