How to access Kubernetes container environment variables from Next.js application?

Question

In my next.config.js, I have a part that looks like this:

module.exports = {
  serverRuntimeConfig: { // Will only be available on the server side
    mySecr         


        

Answer 1

You can create a config-map and then mount it as a file in your deployment with your custom environment variables.

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "38"
  creationTimestamp: xx
  generation: 40
  labels:
    app: appname
  name: appname
  namespace: development
  resourceVersion: xx
  selfLink: /apis/extensions/v1beta1/namespaces/development/deployments/appname
  uid: xxx
spec:
  progressDeadlineSeconds: xx
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: appname
      tier: sometier
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: appname
        tier: sometier
    spec:
      containers:
        - env:
            - name: NODE_ENV
              value: development
            - name: PORT
              value: "3000"
            - name: SOME_VAR
              value: xxx
            - name: SOME_VAR
              value: xxxx
          volumeMounts:
            - name: environment-variables
              mountPath: "your/path/to/store/the/file"
              readOnly: true
          image: someimage
          imagePullPolicy: Always
          name: appname
          readinessProbe:
            failureThreshold: 3
            httpGet:
              path: /healthz
              port: 3000
              scheme: HTTP
            initialDelaySeconds: 5
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 1
          resources:
            requests:
              cpu: 100m
              memory: 100Mi
          terminationMessagePath: /dev/termination-log
          terminationMessagePolicy: File
      volumes:
        - name: environment-variables
          configMap:
            name: environment-variables
            items:
              - key: .env
                path: .env
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30
status:
  availableReplicas: 1
  conditions:
    - lastTransitionTime: xxx
      lastUpdateTime: xxxx
      message: Deployment has minimum availability.
      reason: MinimumReplicasAvailable
      status: "True"
      type: Available
  observedGeneration: 40
  readyReplicas: 1
  replicas: 1
  updatedReplicas: 1

I added the following configuration in your deployment file:

      volumeMounts:
        - name: environment-variables
          mountPath: "your/path/to/store/the/file"
          readOnly: true
  volumes:
    - name: environment-variables
      configMap:
        name: environment-variables
        items:
          - key: .env
            path: .env

You can then create a config map with key ".env" with your environment variables on kubernetes.

Configmap like this:

apiVersion: v1
kind: ConfigMap
metadata:
  name: environment-variables
  namespace: your-namespace
data:
  .env: |
    variable1: value1
    variable2: value2