You can dynamically configure your application by passing environment variables to the container hosting your application image by adding them to the pod template specification in your Helm chart.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: acme-api-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: acme-api
  template:
    metadata:
      labels:
        app: acme-api
    spec:
      containers:
        - name: api-container
          image: public.ecr.aws/ach42q1u/acme-api:1.0.0
          ports:
            - containerPort: 8080
          env:
            - name: APP_PORT
              value: '8080'
            - name: DB_USER
              value: '{{ .Values.db.user }}'
            - name: DB_PASS
              value: '{{ .Values.db.pass }}'
            - name: DB_HOST
              value: '{{ .Values.db.host }}'
            - name: DB_PORT
              value: '{{ .Values.db.port }}'

You can set the values for these environment variables directly, such as APP_PORT in this example.

You can also use Helm values to customize your application’s configuration for each environment you wish to create.

db:
  host: postgres-service
  user: postgres
  pass: postgres
  port: 5432

The environment variables DB_USER, DB_PASS, DB_HOST, and DB_PORT are set dynamically during each deployment.