You can use the **HTTP rewrite** with the virtual service before sending traffic further
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: ratings-route
spec:
hosts:
- ratings.prod.svc.cluster.local
http:
- match:
- uri:
prefix: /ratings
rewrite:
uri: /v1/bookRatings
route:
- destination:
host: ratings.prod.svc.cluster.local
subset: v1
Read more at official document : https://istio.io/latest/docs/reference/config/networking/virtual-service/#HTTPRewrite
If you don't want to use your domains as a virtual service hosts I would say the only options here would be to
- use rewrite in your virtual service.
- use custom headers
There is an example about rewrite from istio documentation.
>**HTTPRewrite**
>
>HTTPRewrite can be used to rewrite specific parts of a HTTP request before forwarding the request to the destination. Rewrite primitive can be used only with HTTPRouteDestination. The following example demonstrates how to rewrite the URL prefix for api call (/ratings) to ratings service before making the actual API call.
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: ratings-route
spec:
hosts:
- ratings.prod.svc.cluster.local
http:
- match:
- uri:
prefix: /ratings
rewrite:
uri: /v1/bookRatings
route:
- destination:
host: ratings.prod.svc.cluster.local
subset: v1
---
There is an example for 2 nginx deployments, both serving on `/`.
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx1
spec:
selector:
matchLabels:
run: nginx1
replicas: 1
template:
metadata:
labels:
run: nginx1
app: frontend
spec:
containers:
- name: nginx1
image: nginx
ports:
- containerPort: 80
lifecycle:
postStart:
exec:
command: ["/bin/sh", "-c", "echo Hello nginx1 > /usr/share/nginx/html/index.html"]
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx2
spec:
selector:
matchLabels:
run: nginx2
replicas: 1
template:
metadata:
labels:
run: nginx2
app: frontend
spec:
containers:
- name: nginx2
image: nginx
ports:
- containerPort: 80
lifecycle:
postStart:
exec:
command: ["/bin/sh", "-c", "echo Hello nginx2 > /usr/share/nginx/html/index.html"]
---
apiVersion: v1
kind: Service
metadata:
name: nginx
labels:
app: frontend
spec:
ports:
- port: 80
protocol: TCP
selector:
app: frontend
---
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
name: comp-ingress-gateway
spec:
selector:
istio: ingressgateway
servers:
- hosts:
- '*'
port:
name: http
number: 80
protocol: HTTP
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: nginxvirt
spec:
gateways:
- comp-ingress-gateway
hosts:
- '*'
http:
- name: match
match:
- uri:
prefix: /a
rewrite:
uri: /
route:
- destination:
host: nginx.default.svc.cluster.local
subset: v1
port:
number: 80
- name: default
match:
- uri:
prefix: /b
rewrite:
uri: /
route:
- destination:
host: nginx.default.svc.cluster.local
subset: v2
port:
number: 80
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: nginxdest
spec:
host: nginx.default.svc.cluster.local
subsets:
- name: v1
labels:
run: nginx1
- name: v2
labels:
run: nginx2
trafficPolicy:
tls:
mode: ISTIO_MUTUAL
And a test with curl.
curl -v xx.xxx.xxx.x/a
HTTP/1.1 200 OK
Hello nginx1
curl -v xx.xxx.xxx.x/b
HTTP/1.1 200 OK
Hello nginx2
---
There is an [example][1] about custom headers in istio documentation.
[1]: https://istio.io/latest/docs/tasks/traffic-management/request-routing/#route-based-on-user-identity
