Kubernetes ConfigMaps

Create a configMap:

kubectl create configmap env-config --from-literal=ENV_VAR_1=FOO --from-literal=ENV_VAR_2=BAR

you can view the result with 

kubectl get  configmap env-config -o yaml

Create a pod to use this configMap

apiVersion: v1
kind: Pod
metadata:
  name: test-pod
spec:
  containers:
    - name: test-container
      image: k8s.gcr.io/busybox
      command: [ "/bin/sh", "-c", "env" ]
      envFrom:
      - configMapRef:
          name: env-config
  restartPolicy: Never

kubectl create -f test-pod.yaml

This pod will print it's env and then exit. You can view the output as follows

kubectl logs test-pod -c test-container

You should see something like...

KUBERNETES_PORT=tcp://10.96.0.1:443
KUBERNETES_SERVICE_PORT=443
HOSTNAME=test-pod
SHLVL=1
HOME=/root
EXAMPLE_SERVICE_PORT_8080_TCP_ADDR=10.100.105.233
EXAMPLE_SERVICE_SERVICE_HOST=10.100.105.233
EXAMPLE_SERVICE_PORT_8080_TCP_PORT=8080
ENV_VAR_1=FOO
ENV_VAR_2=BAR
EXAMPLE_SERVICE_PORT_8080_TCP_PROTO=tcp
KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1
EXAMPLE_SERVICE_PORT=tcp://10.100.105.233:8080
EXAMPLE_SERVICE_SERVICE_PORT=8080
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
KUBERNETES_PORT_443_TCP_PORT=443
KUBERNETES_PORT_443_TCP_PROTO=tcp
EXAMPLE_SERVICE_PORT_8080_TCP=tcp://10.100.105.233:8080
KUBERNETES_SERVICE_PORT_HTTPS=443
KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443
PWD=/
KUBERNETES_SERVICE_HOST=10.96.0.1