istio load balancing of a single service with multiple versions - kubernetes

Question

I was able to achieve load-balancing with sample istio applications
https://github.com/piomin/sample-istio-services
https://istio.io/docs/guides/bookinfo/
But was not able to get istio load-balancing working with single private service having 2 versions. Example: 2 consul servers with different versions .
Service and pod definition :
apiVersion: v1
kind: Service
metadata:
name: consul-test
labels:
app: test
spec:
ports:
- port: 8500
name: http
selector:
app: test
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: consul-test-v1
spec:
replicas: 1
template:
metadata:
labels:
app: test
version: v1
spec:
containers:
- name: consul-test-v1
image: consul:latest
ports:
- containerPort: 8500
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: consul-test-v2
spec:
replicas: 1
template:
metadata:
labels:
app: test
version: v2
spec:
containers:
- name: consul-test-v2
image: consul:1.1.0
ports:
- containerPort: 8500
Gateway definition:
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
name: http-gateway
spec:
selector:
istio: ingressgateway # use istio default controller
servers:
- port:
number: 80
name: http
protocol: HTTP
hosts:
- "*"
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: con-gateway
spec:
hosts:
- "*"
gateways:
- http-gateway
http:
- match:
- uri:
exact: /catalog
route:
- destination:
host: consul-test
port:
number: 8500
Routing rules in virtual service:
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: consul-test
spec:
hosts:
- consul-test
gateways:
- con-gateway
- mesh
http:
- route:
- destination:
host: consul-test
subset: v1
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: consul-test
spec:
host: consul-test
subsets:
- name: v1
labels:
version: v1
- name: v2
labels:
version: v2
Though I route all traffic ( http requests ) to consul server version v1, my http requests on consul-service lands on v1 and v2 alternately i.e, it follows Round-Robin rule .
$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
consul-test ClusterIP 10.97.200.140 <none> 8500/TCP 9m
$ curl -L http://10.97.200.140:8500/v1/catalog/nodes
[
{
"ID": "ebfa341b-4557-a392-9f8a-8ee307113faa",
"Node": "consul-test-v1-765dd566dd-6cmj9",
"Address": "127.0.0.1",
"Datacenter": "dc1",
"TaggedAddresses": {
"lan": "127.0.0.1",
"wan": "127.0.0.1"
},
"Meta": {
"consul-network-segment": ""
},
"CreateIndex": 9,
"ModifyIndex": 10
}
]
$ curl -L http://10.97.200.140:8500/v1/catalog/nodes
[
{
"ID": "1b60a5bd-9a17-ff18-3a65-0ff95b3a836a",
"Node": "consul-test-v2-fffd475bc-st4mv",
"Address": "127.0.0.1",
"Datacenter": "dc1",
"TaggedAddresses": {
"lan": "127.0.0.1",
"wan": "127.0.0.1"
},
"Meta": {
"consul-network-segment": ""
},
"CreateIndex": 5,
"ModifyIndex": 6
}
]

Answer 1

I have the above mentioned issue when curl is done on the service ClusterIP:ClusterPort
$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
consul-test ClusterIP 10.97.200.140 <none> 8500/TCP 9m
$ curl -L http://10.97.200.140:8500/v1/catalog/nodes
But LoadBalancing works as expected when curl is done on INGRESS_HOST and INGRESS_PORT ( determining INGRESS_HOST and INGRESS_PORT present here )
$ curl -L http://$INGRESS_HOST:$INGRESS_PORT/v1/catalog/nodes --- WORKS