How is the security of requests between services ensured in a microservices architecture?

In a microservices architecture, request security between services is ensured by several key methods:

• Authentication and Authorization: each service verifies that the request originates from a trusted source. OAuth 2.0, JWT (JSON Web Tokens), or mTLS (mutual TLS) are often used to confirm the identity of services.

• Traffic Encryption: all communications between services occur over secure channels, such as TLS, to prevent data interception and tampering.

• Network Policies and Segmentation: using service meshes (e.g., Istio) or Kubernetes network policies to restrict service access to only what is necessary.

• Logging and Monitoring: tracking requests and anomalies helps quickly identify and respond to potential threats.

Example of using mTLS in Go with gRPC:

creds, err := credentials.NewClientTLSFromFile("ca.pem", "")
if err != nil {
    log.Fatalf("Failed to create TLS credentials %v", err)
}
conn, err := grpc.Dial(address, grpc.WithTransportCredentials(creds))
if err != nil {
    log.Fatalf("Failed to dial: %v", err)
}
// Now the connection is secured and authenticated

Thus, security is achieved through a combination of measures at the protocol, infrastructure, and application levels.