Configure Environment Variable in Applications

docker run -e APP_COLOR=pink simple-webapp-color

pod-definition.yaml

apiVersion: v1
kind: Pod
metadata:
  name: simple-webapp-color
spec:
  containers:
  - name: simple-webapp-color
    image: simple-webapp-color
    ports:
      - containerPort: 8080
    env:
      - name: APP_COLOR
        value: pink

 

APP_COLOR: blue
APP_MODE: prod

 

1st Create ConfigMap

 

[imperative]

kubectl create configmap
    <<config-name>> --from-literal=<key>=<value>

예시

kubectl create configmap \
    app-config --from-literal=APP_COLOR=blue \
               --from-literal=APP_MODE=prod

Another Way

kubectl create configmap
    <<config-name> --from-file=<path-to-file>

예시

kubectl create configmap \
    app-config --from-file-=app_config.properties

 

[Declarative]

kubectl create -f

config-map.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: app-config
data:
  APP_COLOR: blue
  APP_MODE: prod

kubectl create -f config-map.yaml

 

[mysql-config]

port: 3306
max_allowed_packet: 128M

mysql-config.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: mysql-config
data:
  port: 3306
  max_allowed_packet: 128M

 

 

[redis-config]

port: 6379
rdb-compression: yes

redis-config.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: redis-config
data:
  port: 6379
  rdb-compression: yes

 

View ConfigMaps

kubectl get configmaps

kubectl describe configmaps

 

2nd Inject into Pods

 

pod-definition.yaml

apiVersion: v1
kind: Pod
metadata:
  name: simple-webapp-color
spec:
  containers:
  - name: simple-webapp-color
    image: simple-webapp-color
    ports:
      - containerPort: 8080
      
    envFrom
    - configMapRef:
          name: app-config