Using Kubernetes envFrom for environment variables

deployment.yml

# Use envFrom to load Secrets and ConfigMaps into environment variables

apiVersion: apps/v1beta2
kind: Deployment
metadata:
  name: mans-not-hot
  labels:
    app: mans-not-hot
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mans-not-hot
  template:
    metadata:
      labels:
        app: mans-not-hot
    spec:
      containers:
        - name: app
          image: gcr.io/mans-not-hot/app:bed1f9d4
          imagePullPolicy: Always
          ports:
            - containerPort: 80
          envFrom:
          - configMapRef:
              name: env-configmap
          - secretRef:
              name: env-secrets

env-configmap.yml

# Use config map for not-secret configuration data

apiVersion: v1
kind: ConfigMap
metadata:
  name: env-configmap
data:
  APP_NAME: Mans Not Hot
  APP_ENV: production

env-secrets.yml

# Use secrets for things which are actually secret like API keys, credentials, etc
# Base64 encode the values stored in a Kubernetes Secret: $ pbpaste | base64 | pbcopy
# The --decode flag is convenient: $ pbpaste | base64 --decode

apiVersion: v1
kind: Secret
metadata:
  name: env-secrets
type: Opaque
data:
  DB_PASSWORD: cDZbUGVXeU5e0ZW
  REDIS_PASSWORD: AAZbUGVXeU5e0ZB

Well, if you wish to use envFrom, then

data:
  key1: value1
  key2: value2

will expose it as if you were doing export key1=value1 && export key2=value2.

Whereas:

data:
  config.yaml: | # note this is a file 
    key1: value1
    key2: value2

Is equivalent to export config.yaml=$(cat config.yaml) (if we ignore that env variables may not have a . in their name)

thk for ur explain, actually in my case with envFrom.configMapRef , only one env exist and its name is config.yaml , value is .yaml ,i seem to know about how configMapRef works

Never hot

Or for loading explicit values from a secret:

env:
- name: PASSWORD
  valueFrom:
    secretKeyRef:
      name: my-credentials
      key: password