Kubernetes (Minikube): environment variable - docker

Question

I'm running a simple spring microservice project with Minikube. I have two projects: lucky-word-client (on port 8080) and lucky-word-server (on port 8888). lucky-word-client has to communicate with lucky-word-server. I want to inject the static Nodeport of lucky-word-server (http://192.*..100:32002) as an environment variable in my Kuberenetes deployment script of lucky-word-client. How I could do?
This is deployment of lucky-word-server:
apiVersion: apps/v1
kind: Deployment
metadata:
name: lucky-server
spec:
selector:
matchLabels:
app: lucky-server
replicas: 1
template:
metadata:
labels:
app: lucky-server
spec:
containers:
- name: lucky-server
image: lucky-server-img
imagePullPolicy: Never
ports:
- containerPort: 8888
This is the service of lucky-word-server:
kind: Service
apiVersion: v1
metadata:
name: lucky-server
spec:
selector:
app: lucky-server
ports:
- protocol: TCP
targetPort: 8888
port: 80
nodePort: 32002
type: NodePort
This is the deployment of lucky-word-client:
apiVersion: apps/v1
kind: Deployment
metadata:
name: lucky-client
spec:
selector:
matchLabels:
app: lucky-client
replicas: 1
template:
metadata:
labels:
app: lucky-client
spec:
containers:
- name: lucky-client
image: lucky-client-img
imagePullPolicy: Never
ports:
- containerPort: 8080
This is the service of lucky-word-client:
kind: Service
apiVersion: v1
metadata:
name: lucky-client
spec:
selector:
app: lucky-client
ports:
- protocol: TCP
targetPort: 8080
port: 80
type: NodePort

Answer 1

Kubernetes automatically injects services as environment variables. https://kubernetes.io/docs/concepts/services-networking/service/#environment-variables
But you should not use this. This won't work unless all the services are in place when you create the pod. It is inspired by "docker" which also moved on to DNS based service discovery now. So "environment based service discovery" is a thing of the past.
Please rely on DNS service discovery. Minikube ships with kube-dns so you can just use the lucky-server hostname (or one of lucky-server[.default[.svc[.cluster[.local]]]] names). Read the documentation: https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/