1. Создать configMap

kubectl create configMap \
   config-name \ 
   --from-literal=ENV_NAME1=env_value1
   --from-literal=ENV_NAME2=env_value2
   --from-literal=ENV_NAME3=env_value3

kubectl create configMap \
   config-name \ 
   --from-file=config-file.properties

config-map.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: config-name
data:
  ENV_NAME1: env_value1
  ENV_NAME2: env_value2

2. Использовать configMap в конфигурации Пода:

yaml_with_configmap.yaml

apiVersion: v1
kind: Pod
metadata:
  name: myapp-pod
  labels:
    name: myapp-pod
spec:
 containers:
   - name: nginx
     image: nginx
     ports:
       - containerPort: 8080
     envFrom: 
       - configMapRef:
         name: config_name