Dfyjkt

I want to deploy many Pods in Google Kubernetes Engine and then establish a TCP connection to each specific Pod by Subdomain like pod-name-or-label.mydomain.com or path routing like protocol://mydomain.com:7878/pod-name-or-label.

I have looked in different directions like Istio or nginx-ingress, but that seems to me to be too complicated.

Is not there a simple solution for that?

For Istio, You can use VirtualService to control the routing rules to the target subset with defining by DestinationRules.

The DestinationRule will route to the target Pods by the specified label pods.

The request flow will like to:

+--------------------+
| |
| Istio Gateway |
| |
| |
+---------+----------+
 |traffic incoming
 |
+---------v----------+
| |
| VirtualService |
| |
| |
+---------+----------+
 |route to subset by the routing rules
 v

+--------------------+
| |
| DestinationRules |
| |
| |
+---------+----------+
 |route traffic to target pods
 v

+--------------------+
| |
| |
| Pods |
| |
+--------------------+

so as @ericstaples said you should create different Deployments with different pod labels to achieve separating traffic to the target pods, Example:

1. create a deployment with pod label: t1


2. create a subset in DestinationRule: select t1 label pod as subset s1


3. control your traffic in VirtualService that route to s1 subset


4. 
   s1 route to the target pods

also for expose Gateway, you can use ClusterIP or NodePort like ** Kubernetes** other service did, see more of Istio Traffic.

There are some references maybe it's helpful:

https://istio.io/docs/concepts/traffic-management/

https://istio.io/docs/tasks/traffic-management/request-routing/

Now i have that solution with istio installed on the cluster:

apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
 name: echo-gateway
spec:
 selector:
 istio: ingressgateway # use istio default controller
 servers:
 - port:
 number: 80
 name: http
 protocol: HTTP
 hosts:
 - "dev.sample.com"

With that gateway i can apply that Deployment, Service, VirtualService

apiVersion: apps/v1
kind: Deployment
metadata:
 name: my-echo-1000-deployment
 labels:
 echoservice: echo-1000
spec:
 replicas: 1
 selector:
 matchLabels:
 echoservice: echo-1000
 template:
 metadata:
 labels:
 echoservice: echo-1000
 spec:
 containers:
 - image: gcr.io/google-containers/echoserver:1.10
 imagePullPolicy: IfNotPresent
 name: my-echo-run-container
 ports:
 - containerPort: 8080
 protocol: TCP

---

apiVersion: v1
kind: Service
metadata:
 name: my-echo-1000-service
 labels:
 echoservice: echo-1000
spec:
 ports:
 - port: 8080
 name: http
 selector:
 echoservice: echo-1000

---

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
 name: my-echo-1000-vservice
spec:
 hosts:
 - "dev.sample.com"
 gateways:
 - echo-gateway
 http:
 - match:
 - uri:
 exact: /echo-1000
 route:
 - destination:
 host: my-echo-1000-service
 port:
 number: 8080

Get the LoadbalancerIP from istio-ingressgateway and make an entry in /etc/hosts for dev.sample.com

Now i can get the echoserver in specific Pod with http://dev.sample.com/echo-1000

Is that a good solution or is there a better one?