Kubernetes expose multiple pods

9/13/2018

I have a kubernetes cluster with multiple pods from different images.

I want to be able to expose each of those pods so I will be able to access them using an external DNS record (outside the cluster).

For example: Let's say I have 3 pods (pod1,pod2,pod3), I want to be able to access them from outside the cluster this way:

http://pod1.mydomain.com

http://pod2.mydomain.com

http://pod3.mydomain.com

Is there a way to do it?

Thanks

-- Shachar Ashkenazi
containers
dns
docker
kubernetes

2 Answers

9/13/2018

In AWS you can easily expose PODs using ELB - Kubernetes can automatically create proper ELBs for you. It means that Kubernetes spawn ELB and then attach it to proper services using nodes ports. When you have ELBs in place you can use external-dns plugin metioned by GarMan which can attach DNS records to those ELBs using AWS Route53 integration. So you need to:

  1. Add proper rights to Kubernetes so he can create ELBs and DNS record in Route53 (part of Kubernetes installation and external-dns plugin installation)
  2. Attach proper service to your pod

Example service would look like:

apiVersion: v1
kind: Service
metadata:
  name: public-pod1
  namespace: your-deployment
  labels:
    app: pod1
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-internal: 0.0.0.0/0
    service.beta.kubernetes.io/aws-load-balancer-backend-protocol: http
    service.beta.kubernetes.io/aws-load-balancer-cross-zone-load-balancing-enabled: "true"
    external-dns.alpha.kubernetes.io/hostname: pod1.mydomain.com.
spec:
  type: LoadBalancer
  loadBalancerSourceRanges:
  - 0.0.0.0/0 # Ingress SG for your ELB
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80 #That should match your app's port
  selector:
    app: pod1
-- Jakub Bujny
Source: StackOverflow

9/13/2018

external-dns (https://github.com/kubernetes-incubator/external-dns) is designed to do this, you annotate your services with the dns name you want to give them, and external-dns creates the relevant dns entries for you.

-- GarMan
Source: StackOverflow