Configure FKS Services

A Kubernetes Service exposes applications running on your cluster. Fly Kubernetes supports ClusterIP and LoadBalancer Services.

You can create a Service with a service configuration file. Here’s an example ClusterIP service:

apiVersion: v1
kind: Service
metadata:
  name: fksdemo-service
spec:
  selector:
    app: fksdemo
  ports:
    - name: http
      protocol: TCP
      port: 80
      targetPort: 8080

Using kubectl, create the service:

> kubectl apply -f service.yaml

To view your service:

> kubectl get svc
NAME              TYPE        CLUSTER-IP            EXTERNAL-IP   PORT(S)   AGE
kubernetes        ClusterIP   fdaa:3:dde8:0:1::3a   <none>        443/TCP   32h
fksdemo-service   ClusterIP   fdaa:3:dde8:0:1::3b   <none>        80/TCP    11s

Exposing Services publicly

Services can be exposed to the public internet with a Service of type LoadBalancer.

apiVersion: v1
kind: Service
metadata:
  name: fksdemo-service-public
spec:
  selector:
    app: fksdemo
  ports:
    - name: http
      protocol: TCP
      port: 80
      targetPort: 8080
  type: LoadBalancer

The domain name and IP address to access the Service over the internet can be found using kubectl. In the below output, the values are found under the EXTERNAL-IP column.

> kubectl get svc
NAME                     TYPE           CLUSTER-IP            EXTERNAL-IP                                                                                           PORT(S)   AGE
kubernetes               ClusterIP      fdaa:3:dde8:0:1::3a   <none>                                                                                                443/TCP   32h
fksdemo-service          ClusterIP      fdaa:3:dde8:0:1::3b   <none>                                                                                                80/TCP    26m
fksdemo-service-public   LoadBalancer   fdaa:3:dde8:0:1::3c   fksdemo-service-public.svc.fks-default-vz5dlqz7v4ylrnpq.fly.dev,2a09:8280:1::31:ab8:0,137.66.25.254   80/TCP    8s

Fly.io connection Handlers

Fly.io connection handlers modify your connection before it reaches your application. Learn more about connection handlers.

Connection handlers are supported with a custom annotation to a Service object. The annotations have the form:

"service.fly.io/<exposed port name/number>-handlers": "<handler1,handler2,...handlerN>"

The example below adds an HTTP and TLS handler for port 443.

apiVersion: v1
kind: Service
metadata:
  name: fksdemo-service
  annotations:
    "service.fly.io/https-handlers": "http,tls" # can replace https with 443
spec:
  selector:
    app: fksdemo
  ports:
    - name: http
      protocol: TCP
      port: 80
      targetPort: 8080
    - name: https
      protocol: TCP
      port: 443
      targetPort: 8080

TLS Options

TLS options are used to configure the TLS settings of a service with a TLS connection handler. Fly’s edge will use these settings to terminate TLS for your application. Refer to the documentation for details.

TLS options are set using custom annotations. There are 3 annotations, one for each setting:

• service.fly.io/<exposed port name/number>-tls-alpn - Sets the ALPN for negotiation with clients. Values must be comma-separated.
• service.fly.io/<exposed port name/number>-tls-versions - Sets which TLS versions are allowed. Values must be comma-separated.
• service.fly.io/<exposed port name/number>-tls-default-self-signed - If true, serves a self-signed certificate if none exists.

The most common use case for TLS options is to support gRPC. For example:

apiVersion: v1
kind: Service
metadata:
  name: fksdemo-service
  annotations:
    "service.fly.io/https-handlers": "tls"
    "service.fly.io/https-tls-alpn": "h2"
spec:
  selector:
    app: fksdemo
  ports:
    - name: http
      protocol: TCP
      port: 80
      targetPort: 8080
    - name: https
      protocol: TCP
      port: 443
      targetPort: 8080

Concurrency limits

Concurrency limits are used to limit the load on your application. By default, the soft limit is set to 20 and the hard limit is set to 25. Learn more about concurrency limits.

They can be configured on your Services using custom annotations. There are 3 annotations used to configure the limits:

• service.fly.io/concurrency-kind - sets the metric used to measure concurrency
• service.fly.io/concurrency-limit-soft - sets the concurrency soft limit
• service.fly.io/concurrency-limit-hard - sets the concurrency hard limit

Below is an example of setting this in your Service

apiVersion: v1
kind: Service
metadata:
  name: fksdemo-service
  annotations:
    "service.fly.io/concurrency-kind": "connections"
    "service.fly.io/concurrency-limit-soft": 20 
    "service.fly.io/concurrency-limit-hard": 25 

Not supported

We currently do not support:

• NodePort Services
• UDP protocol

Related topics

• Create an FKS cluster
• Connect to an FKS cluster