Actions

Kubernetes/ConfigMap

From Ever changing code

< Kubernetes

ConfigMap object allows to manage application's configuration using Kubernetes primitives. YAML below:

ConfigMap
As a environment Mounted volume Secrets mounted volume
apiVersion: v1
kind: Pod
metadata: 
  name: configmap-kube
spec:
  containers:
  - name: nginx
    image: nginx
    command: ['sh', '-c', "echo $(VAR) && sleep 600"]
    env:
    - name: VAR
      valueFrom:
        configMapKeyRef:
          name: kubeapp-config
          key: value1
apiVersion: v1
kind: Pod
metadata:
  name: configmap-volume-kube
spec:
  containers:
  - name: nginx
    image: nginx
    command: ['sh', '-c', "echo $(MY_VAR) && sleep 3600"]
    volumeMounts:
      - name: configmapvolume
        mountPath: /etc/config
  volumes:
    - name: configmapvolume
      configMap:
        name: kubeapp-config
apiVersion: v1
kind: Pod
metadata:
  name: kube-secret-volume-pod
spec:
  containers:
  - name: nginx
    image: nginx
    command: ['sh', '-c', "echo $(MY_VAR) && sleep 3600"]
    volumeMounts:
      - name: secretvolume
        mountPath: /etc/certs
  volumes:
    - name: secretvolume
      secret:
        secretName: kube-secret


Deploy

kubectl apply -f configmap-pod.yaml
kubectl logs configmap-pod         #Get the logs from the pod displaying the value

Another way to provide values from a ConfigMap is to mount as a container's volume. The keys you can see within the container

kubectl exec configmaps-volume-kube -- ls  /etc/config
kubectl exec configmaps-volume-kube -- cat /etc/config/key1


The YAML for a secret:

apiVersion: v1
kind: Secret
metadata:
  name: kube-secret
stringData:
  cert: 1234abc
  key: ca.crt


Create secrets

kubectl apply -f secrets.yaml
kubectl describe secrets appsecret 
Name:         kube-secret
Namespace:    default
Labels:       <none>
Annotations:  
Type:         Opaque

Data
====
cert:  5 bytes
key:   5 bytes

References