ConfigMap

ConfigMap是一种比较特殊的存储卷，它的主要作用是用来存储配置信息的。

Secret

在kubernetes中，还存在一种和ConfigMap非常类似的对象，称为Secret对象。它主要用于存储敏感信息，例如密码、秘钥、证书等等。

创建configmap 

1. 先创建username.txt ，password.txt 文件，输入对应用户名和密码信息

[root@k8s-master1 ConfigMap_secret]# cat username.txt 
xm
[root@k8s-master1 ConfigMap_secret]# cat 
123456

2. 使用kubectl命令导出yaml文件

[root@k8s-master1 ConfigMap_secret]#  kubectl create configmap configmap -n my-ns-xmcc --from-file=username.txt --from-file=password.txt --dry-run -o yaml > configmap.yaml

[root@k8s-master1 ConfigMap_secret]# cat configmap.yaml 
apiVersion: v1
data:
  password.txt: |
    123456
  username.txt: |
    xm
kind: ConfigMap
metadata:
  creationTimestamp: null
  name: configmap1
  namespace: my-ns-xmcc
 
#使用此配置文件创建configmap
[root@k8s-master1 ConfigMap_secret]# kubectl apply -f configmap.yaml 
Warning: kubectl apply should be used on resource created by either kubectl create --save-config or kubectl apply
configmap/configmap configured
[root@k8s-master1 ConfigMap_secret]# kubectl get cm -n my-ns-xmcc 
NAME        DATA   AGE
configmap   1      3m3s
# 查看configmap详情
[root@k8s-master1 ConfigMap_secret]# kubectl describe cm configmap -n my-ns-xmcc
Name:         configmap
Namespace:    my-ns-xmcc
Labels:       <none>
Annotations:  <none>

Data
====
info:
----
username: xm
password: 123456

Events:  <none>

3. 接下来创建一个deployment，将上面创建的configmap挂载进pod中

先用命令导出yaml文件

[root@k8s-master1 ConfigMap_secret]# kubectl create deploy deploy-xmcc -n my-ns-xmcc --image=centos-nginx:1.23.1 --dry-run -oyaml >> deploy.yaml

修改yaml文件，加入configmap配置信息

[root@k8s-master1 ConfigMap_secret]# cat deploy.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: deploy-xmcc
  name: deploy-xmcc
  namespace: my-ns-xmcc
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: deploy-xmcc
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: deploy-xmcc
    spec:
      containers:
      - image: centos-nginx:1.23.1
        imagePullPolicy: IfNotPresent
        name: centos-nginx
        resources: {}
        volumeMounts:     #configmap挂载上去
        - name: config
          mountPath: /configmap/config
      volumes:
      - name: config
        configMap:
          name: configmap
      dnsPolicy: ClusterFirst
      restartPolicy: Always

#使用配置文件创建deployment
[root@k8s-master1 ConfigMap_secret]# kubectl apply -f deploy.yaml 
Warning: kubectl apply should be used on resource created by either kubectl create --save-config or kubectl apply

#查询资源
[root@k8s-master1 ConfigMap_secret]# kubectl get all -n my-ns-xmcc 
NAME                              READY   STATUS    RESTARTS   AGE
pod/deploy-xmcc-7b49c87f8-zg6sp   1/1     Running   0          57s

NAME                          READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/deploy-xmcc   1/1     1            1           7m44s

NAME                                     DESIRED   CURRENT   READY   AGE
replicaset.apps/deploy-xmcc-5d64d5c64d   0         0         0       7m44s
replicaset.apps/deploy-xmcc-7b49c87f8    1         1         1       57s

#进入容器
[root@k8s-master1 ConfigMap_secret]# kubectl exec -it -n my-ns-xmcc deploy-xmcc-7b49c87f8-zg6sp /bin/bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
[root@deploy-xmcc-7b49c87f8-zg6sp /]# cd /configmap/config/
[root@deploy-xmcc-7b49c87f8-zg6sp config]# ll
total 0
lrwxrwxrwx 1 root root 11 Sep 20 10:17 info -> ..data/info 
[root@deploy-xmcc-7b49c87f8-zg6sp config]# cat info 
username: xm
password: 123456
# 可以看到映射已经成功，每个configmap都映射成了一个目录 
# key--->文件 value---->文件中的内容 
# 此时如果更新configmap的内容, 容器中的值也会动态更新

Secret

在kubernetes中，还存在一种和ConfigMap非常类似的对象，称为Secret对象。它主要用于存储敏感信息，例如密码、秘钥、证书等等。

#首先使用base64对数据进行编码
[root@k8s-master1 ConfigMap_secret]# echo 'xm' |base64
eG0K
[root@k8s-master1 ConfigMap_secret]# echo '123456'|base64
MTIzNDU2Cg==
#解码的话，在上面命令加-d参数
[root@k8s-node1 ~]# echo eG0K | base64 -d
xm
[root@k8s-node1 ~]# echo MTIzNDU2Cg== | base64 -d
123456
#把编码存放在txt文件
[root@k8s-master1 ConfigMap_secret]# echo -n 'xm' | base64 >> username.txt
[root@k8s-master1 ConfigMap_secret]# echo -n '123456' | base64 >> password.txt
[root@k8s-master1 ConfigMap_secret]# cat username.txt 
eG0=
[root@k8s-master1 ConfigMap_secret]# cat password.txt 
MTIzNDU2
#使用kubectl命令创建，导出yaml文件
[root@k8s-master1 ConfigMap_secret]# kubectl create secret generic db-user-pass --from-file=./username.txt --from-file=./password.txt -n my-ns-xmcc --dry-run -o yaml >> db-user-pass-secret.yaml
#查询对应的yaml文件，可以根据需要修改
[root@k8s-master1 ConfigMap_secret]# cat db-user-pass-secret.yaml 
apiVersion: v1
data:
  password.txt: TVRJek5EVTIK
  username.txt: ZUcwPQo=
kind: Secret
metadata:
  creationTimestamp: null
  name: db-user-pass
  namespace: my-ns-xmcc
#修改后的yaml文件，使用yaml文件创建Secret
[root@k8s-master1 ConfigMap_secret]# cat secret.yaml 
apiVersion: v1
kind: Secret
metadata:
  name: secret
  namespace: my-ns-xmcc
type: Opaque
data:
  username: eG0K
  password: MTIzNDU2Cg==
  
 # 创建secret
 [root@k8s-master1 ConfigMap_secret]# kubectl create -f secret.yaml 
secret/secret created

# 查看secret详情
[root@k8s-master1 ConfigMap_secret]# kubectl describe secret secret -n my-ns-xmcc 
Name:         secret
Namespace:    my-ns-xmcc
Labels:       <none>
Annotations:  <none>

Type:  Opaque

Data
====
password:  7 bytes
username:  3 bytes

#创建deployment，将上面创建的secret挂载进去：

[root@k8s-master1 ConfigMap_secret]# cat deploy-secret.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: deploy-xmcc-secret
  name: deploy-xmcc-secret
  namespace: my-ns-xmcc
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: deploy-xmcc-secret
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: deploy-xmcc-secret
    spec:
      containers:
      - image: centos-nginx:1.23.1
        imagePullPolicy: IfNotPresent
        name: centos-nginx
        resources: {}
        volumeMounts:      #挂载secret存储
        - name: config
          mountPath: /secret/config
      volumes:
      - name: config
        secret:
          secretName: secret
      dnsPolicy: ClusterFirst
      restartPolicy: Always

#创建deploy资源
[root@k8s-master1 ConfigMap_secret]# kubectl create -f deploy-secret.yaml 
deployment.apps/deploy-xmcc-secret created

#查询资源
[root@k8s-master1 ConfigMap_secret]# kubectl get all -n my-ns-xmcc 
NAME                                      READY   STATUS    RESTARTS   AGE
pod/deploy-xmcc-7b49c87f8-zg6sp           1/1     Running   0          5h51m
pod/deploy-xmcc-secret-54554c554f-gpwx7   1/1     Running   0          19s

NAME                                 READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/deploy-xmcc          1/1     1            1           5h58m
deployment.apps/deploy-xmcc-secret   1/1     1            1           19s

NAME                                            DESIRED   CURRENT   READY   AGE
replicaset.apps/deploy-xmcc-5d64d5c64d          0         0         0       5h58m
replicaset.apps/deploy-xmcc-7b49c87f8           1         1         1       5h51m
replicaset.apps/deploy-xmcc-secret-54554c554f   1         1         1       19s

#进入容器，查看secret信息，发现已经自动解码了
[root@k8s-master1 ConfigMap_secret]# kubectl exec -it -n my-ns-xmcc deploy-xmcc-secret-54554c554f-gpwx7 /bin/bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
[root@deploy-xmcc-secret-54554c554f-gpwx7 /]# cd /secret/config/
[root@deploy-xmcc-secret-54554c554f-gpwx7 config]# ll
total 0
lrwxrwxrwx 1 root root 15 Sep 20 16:08 password -> ..data/password
lrwxrwxrwx 1 root root 15 Sep 20 16:08 username -> ..data/username
[root@deploy-xmcc-secret-54554c554f-gpwx7 config]# cat username 
xm
[root@deploy-xmcc-secret-54554c554f-gpwx7 config]# cat password 
123456

至此，已经实现了利用secret实现了信息的编码。