First of all, I'd like to say that I'm new to Kubernetes, so forgive me if what I want to do is a bad idea :)

Here's my context : I've got a very large application which is composed of lots of micro-services according to their domains :

Domain 1
    domain1-microservice1-app expose port 8080
    domain1-microservice2-app expose port 8081
    domain1-microservice3-app expose port 8082

Domain 2
    domain2-microservice1-app expose port 9080
    domain2-microservice2-app expose port 9081
    domain2-microservice3-app expose port 9082

Domain 3
    domain3-microservice1-app expose port 9180
    domain3-microservice2-app expose port 9181
    domain3-microservice3-app expose port 9182

... and so on.

So, in my example, I have 9 applications. Each application is registered in Kubernetes using kind:Deployment

Now I want to choose the best way to manage services.

First solution

Each deployment has its own service

\=> It works, it seems to be the classical way of doing things in Kubernetes. But in reality, I have far more than 9 applications, so I have lots of services

Second solution

Create a service by domain. Each service contains all its related apps

\=> I've tried it and it seems to work (as far as I could test in my local dev environment)

I'd like to know what do you think of my second solution, and what may be its caveat?

I also take all your advice on what could be the best Kubernetes structure.

Thanks a lot,

Julien

Edit: add sample configuration files for approach 2

Deployment file for microservice1 of domain1 :

apiVersion: apps/v1
kind: Deployment
metadata:
    name: domain1-app1
    labels: 
        domain: domain1  
spec:
    selector:
        matchLabels:
            app: domain1-app1
    replicas: 3
    template:
        metadata:
            labels:
                app: domain1-app1
                domain: domain1
        spec:
            containers:
                - name: XXX
                image: YYY
                ports:
                - containerPort: 8080

Service file for service related to domain 1 :

kind: Service
apiVersion: v1
metadata:
    name: domain1-service
spec:
    type: LoadBalancer
    selector:
        domain: domain1
    ports:
        - name: port8080
        protocol: TCP
        port: 8080
        targetPort: 8080
        - name: port8081
        protocol: TCP
        port: 8081
        targetPort: 8081
        - name: port8082
        protocol: TCP
        port: 8082
        targetPort: 8082