VirtualService Routing¶
How your app gets its URL¶
External requests reach your app at /${ENTITY_NAMESPACE}/${APP_SLUG}/... — today, that's /hello-world/....
This is set through values.yaml → istio.pathPrefix.
VirtualService configuration¶
Everything below is driven by values.yaml, except the URL rewrite:
| Field | Value key | Default |
|---|---|---|
| Host | istio.host |
api.playground.france-identite.gouv.local |
| Gateway | istio.gateway |
istio-system/api-gateway |
| URL prefix to match | istio.pathPrefix |
/hello-world/ |
| URL rewrite | (hardcoded) | / |
| Destination service | (derived from the chart name) | helm-hello-world |
| Destination port | service.port |
5173 |
Don't change
istio.hostoristio.gateway— they point at the platform's shared API Gateway. The only thing you should adapt per service isistio.pathPrefix, and it must be unique: if two services use the same prefix, their traffic will collide.
How a request travels through the system¶
Client → Istio Gateway (istio.host)
→ VirtualService (matches istio.pathPrefix, rewrites to /)
→ Service (service.port = 5173)
→ Your pod's container (service.containerPort = 80)
- The request arrives at the gateway for
istio.host - Istio checks whether the path matches your
istio.pathPrefix - If it matches, the URL is rewritten to
/ - Traffic is forwarded to your Service
- The Service forwards it to your container's port
Which value drives which field¶
| Template field | Value key | Configurable via values.yaml? |
|---|---|---|
metadata.name |
Chart name | Yes |
spec.hosts |
istio.host |
Yes |
spec.gateways |
istio.gateway |
Yes |
spec.http.match.uri.prefix |
istio.pathPrefix |
Yes |
spec.http.rewrite.uri |
(hardcoded to /) |
No |
spec.http.route.destination.host |
Chart name | Yes |
spec.http.route.destination.port.number |
service.port |
Yes |
Before you change anything, check the ports line up¶
- VirtualService's destination port must equal
service.port - Service's
targetPortmust equalservice.containerPort
Assumption¶
The gateway istio-system/api-gateway already exists and is configured for this VirtualService's host. It's referenced by the chart but not created by it.