A service mesh is a dedicated infrastructure layer for communication between services. It manages interservice observability, traffic, and security without requiring application code changes or application redeployments. section 13.1.2 section 13.7
A service mesh applies to:
- East/west traffic: communication between services inside a cluster. section 13.7
- Traffic management, observability, and security between services. section 13.1.2
- Configuration-driven changes that avoid reconfiguring or redeploying applications in the mesh. section 13.7
Routing directly between services
The Gateway API Mesh Management and Administration (GAMMA) approach can configure an HTTPRoute whose parent is a destination Service rather than a Gateway. This supports interservice traffic flowing directly between services instead of through an additional gateway. section 13.7
kind: HTTPRoute
metadata:
name: my-interservice-route
spec:
parentRefs:
- name: destination-service
kind: Service
group: core
port: 80
rules:
- ...
Use an HTTPRoute with a Service parentRef to represent an interservice route. section 13.7
Istio can implement the Gateway API and can also serve as a service mesh. These roles are separable: Istio may provide the Gateway API without requiring use of its service-mesh functionality. Service-mesh configuration has also been addressed by the Service Mesh Interface (SMI) and the Gateway API GAMMA initiative. section 13.1.2 section 13.7
