Interview › Istio & Service Mesh
What is a VirtualService, and what does it control?
Istio & Service Mesh · Basic level
Answer
A VirtualService defines traffic-routing rules for one or more hosts. It controls how requests are matched and routed based on host, URI path, headers, ports, weights, retries, timeouts, fault injection, and mirroring.
Technical explanation
VirtualService is usually paired with DestinationRule when routing to named subsets such as v1 and v2.
It can apply to internal mesh traffic or to traffic entering through a Gateway.
It is a powerful production object, so changes should be reviewed, validated, and rolled out like application code.
Hands-on example
Example route by path:
apiVersion: networking.istio.io/v1
kind: VirtualService
metadata:
name: reviews
spec:
hosts: [reviews]
http:
- match:
- uri:
prefix: /v2
route:
- destination:
host: reviews
subset: v2
- route:
- destination:
host: reviews
subset: v1
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