Secret密码管理 和 ConfigmMap配置管理

configmap 和 secret 配置基本一样，两者区别是secret是以加密的方式存储在etcd，而configmap是以文明方式存储，secret适合存储密码等信息，configmap适合存储配置信息。

Secret密码管理：

kubectl create secret generic secret1 --from-file=/etc/hosts --from-file=/etc/passwd
kubectl create secret generic secret2 --from-literal=root=root123 --from-literal=admin=admin123
kubectl create secret generic secret2 --from-file=key1=/etc/hosts

kubectl describe secrets 
kubectl describe secrets secret2
kubectl get secrets secret3 -o jsonpath={.data.key1}|base64 -d
# kubectl get secrets secret2 -o yaml
apiVersion: v1
data:
  admin: YWRtaW4xMjM=
  root: cm9vdDEyMw==
kind: Secret
metadata:
  creationTimestamp: "2021-05-17T12:31:07Z"
  name: secret2
  namespace: default
  resourceVersion: "1085377"
  selfLink: /api/v1/namespaces/default/secrets/secret2
  uid: f5273b0d-47c6-4101-a876-f25f762d4bc6
type: Opaque

# echo "YWRtaW4xMjM=" | base64 -d
admin123
# kubectl get secrets secret2 -o jsonpath={.data.root}|base64  -d
root123
# kubectl get secrets secret1 -o  jsonpath={.data.hosts} |base64 -d

以卷的方式使用secret:

[root@k8s-master ~]# cat pod1.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: pod1
spec:
  volumes:
  - name: xx
    secret:
      secretName: secret1
  containers:
  - image: nginx
    name: pod
    imagePullPolicy: IfNotPresent
    volumeMounts:
    - name: xx
      mountPath: /opt/hosts
      subPath: hosts

[root@k8s-master ~]# kubectl apply -f pod1.yaml 

[root@k8s-master ~]# kubectl exec -it pod1 -- cat /opt/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.2.11 k8s-master
192.168.2.12 k8s-worker 
192.168.2.12 gitlab.example.com
192.168.2.100 harbor.example.com

变量的方式使用secret:

[root@k8s-master ~]# cat mysql1.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: mysql
spec:
  containers:
  - name: mysql
    image: mysql:5.7
    imagePullPolicy: IfNotPresent
    env:
    - name: MYSQL_ROOT_PASSWORD
      valueFrom:
        secretKeyRef:
          name: secret2
          key: root

[root@k8s-master ~]# kubectl apply -f mysql1.yaml 

[root@k8s-master ~]# kubectl exec -it mysql -- env | grep ROOT
MYSQL_ROOT_PASSWORD=root123

ConfigMap配置管理：

[root@k8s-master ~]# kubectl create configmap config-1 --from-file=/etc/hosts

[root@k8s-master ~]# kubectl get configmaps config-1 -o yaml
apiVersion: v1
data:
  hosts: "127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4\n::1
    \        localhost localhost.localdomain localhost6 localhost6.localdomain6\n192.168.2.11
    k8s-master\n192.168.2.12 k8s-worker \n192.168.2.12 gitlab.example.com\n192.168.2.100
    harbor.example.com\n\n"
kind: ConfigMap
metadata:
  creationTimestamp: "2021-05-17T13:43:35Z"
  name: config-1
  namespace: default
  resourceVersion: "1097930"
  selfLink: /api/v1/namespaces/default/configmaps/config-1
  uid: 6aea3a6a-a753-4e66-a453-ec4bc77d6e53

[root@k8s-master ~]# kubectl get configmaps config-1 -o jsonpath={.data.hosts}
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.2.11 k8s-master
192.168.2.12 k8s-worker 
192.168.2.12 gitlab.example.com
192.168.2.100 harbor.example.com