kubernetes(五)--存储之configmap/secret/volume/Persistent Volume

一、configmap

1.1、configmap简介

ConfigMap 功能在 Kubernetes1.2 版本中引入，许多应用程序会从配置文件、命令行参数或环境变量中读取配置信息。ConfigMap API 给我们提供了向容器中注入配置信息的机制，ConfigMap 可以被用来保存单个属性，也可以用来保存整个配置文件或者 JSON 二进制对象

1.2、ConfigMap 的创建

1.2.1、使用目录创建

[root@k8s-master01 dir]# ls
game.propertie  ui.propertie
[root@k8s-master01 dir]# cat game.propertie 
enemies=aliens
lives=3
enemies.cheat=true
enemies.cheat.level=noGoodRotten
secret.code.passphrase=UUDDLRLRBABAS
secret.code.allowed=true
secret.code.lives=30
[root@k8s-master01 dir]# cat ui.propertie 
color.good=purple
color.bad=yellow
allow.textmode=true
how.nice.to.look=fairlyNice

#从目录创建configmap
#—from-file指定在目录下的所有文件都会被用在 ConfigMap 里面创建一个键值对，键的名字就是文件名，值就是文件的内容
[root@k8s-master01 dir]# kubectl create configmap game-config --from-file=./
configmap/game-config created
[root@k8s-master01 dir]# kubectl get configmap
NAME          DATA   AGE
game-config   2      14s
[root@k8s-master01 dir]# kubectl get cm
NAME          DATA   AGE
game-config   2      18s
[root@k8s-master01 dir]# kubectl get cm game-config -o yaml
apiVersion: v1
data:
  game.propertie: |
    enemies=aliens
    lives=3
    enemies.cheat=true
    enemies.cheat.level=noGoodRotten
    secret.code.passphrase=UUDDLRLRBABAS
    secret.code.allowed=true
    secret.code.lives=30
  ui.propertie: |
    color.good=purple
    color.bad=yellow
    allow.textmode=true
    how.nice.to.look=fairlyNice
kind: ConfigMap
metadata:
  creationTimestamp: "2020-02-04T05:13:30Z"
  name: game-config
  namespace: default
  resourceVersion: "144337"
  selfLink: /api/v1/namespaces/default/configmaps/game-config
  uid: 0fc2df14-d5ee-4092-ba9e-cc733e8d5893
[root@k8s-master01 dir]# kubectl describe cm game-config
Name:         game-config
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
game.propertie:
----
enemies=aliens
lives=3
enemies.cheat=true
enemies.cheat.level=noGoodRotten
secret.code.passphrase=UUDDLRLRBABAS
secret.code.allowed=true
secret.code.lives=30

ui.propertie:
----
color.good=purple
color.bad=yellow
allow.textmode=true
how.nice.to.look=fairlyNice

Events:  <none>

1.2.2、使用文件创建

只要指定为一个文件就可以从单个文件中创建 ConfigMap

—from-file这个参数可以使用多次，你可以使用两次分别指定上个实例中的那两个配置文件，效果就跟指定整个目录是一样的

[root@k8s-master01 dir]# kubectl create configmap game-config-2 --from-file=./game.propertie
configmap/game-config-2 created
[root@k8s-master01 dir]# kubectl get cm game-config-2
NAME            DATA   AGE
game-config-2   1      16s
[root@k8s-master01 dir]# kubectl get cm game-config-2 -o yaml
apiVersion: v1
data:
  game.propertie: |
    enemies=aliens
    lives=3
    enemies.cheat=true
    enemies.cheat.level=noGoodRotten
    secret.code.passphrase=UUDDLRLRBABAS
    secret.code.allowed=true
    secret.code.lives=30
kind: ConfigMap
metadata:
  creationTimestamp: "2020-02-04T05:25:13Z"
  name: game-config-2
  namespace: default
  resourceVersion: "145449"
  selfLink: /api/v1/namespaces/default/configmaps/game-config-2
  uid: df209574-202d-4564-95ca-19532abd6b7b

1.2.3、使用字面值创建

使用文字值创建，利用—from-literal参数传递配置信息，该参数可以使用多次

[root@k8s-master01 dir]# kubectl create configmap special-config --from-literal=special.how=very --from-literal=special.type=charm
configmap/special-config created
[root@k8s-master01 dir]# kubectl get cm special-config -o yaml
apiVersion: v1
data:
  special.how: very
  special.type: charm
kind: ConfigMap
metadata:
  creationTimestamp: "2020-02-04T05:27:43Z"
  name: special-config
  namespace: default
  resourceVersion: "145688"
  selfLink: /api/v1/namespaces/default/configmaps/special-config
  uid: 72b58e0e-f055-43dd-aa04-a7b2e9007227

1.3、Pod中使用Configmap

1.3.1、使用configmap代替环境变量

#创建config文件
[root@k8s-master01 usage]# cat config.yaml 
apiVersion: v1
kind: ConfigMap
metadata:  
  name: special-config  
  namespace: default
data:  
  special.how: very
  special.type: charm

---
apiVersion: v1
kind: ConfigMap
metadata:  
  name: env-config  
  namespace: default
data:  
  log_level: INFO
[root@k8s-master01 usage]# kubectl apply -f config.yaml
configmap/special-config created
configmap/env-config created

#将ConfigMap文件注入到pod环境中
[root@k8s-master01 usage]# cat dapi-test.pod.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: dapi-test-pod
spec:
  containers:
    - name: test-container
      image: hub.dianchou.com/library/myapp:v1
      command: ["/bin/sh","-c","env"]
      env:                           #第一种导入方案
        - name: SPECIAL_LEVEL_KEY
          valueFrom:
            configMapKeyRef:
              name: special-config   #从哪个configMap导入
              key: special.how       #导入的是键名，就是将special.how键的键值赋予SPECIAL_LEVEL_KEY
        - name: SPECIAL_TYPE_KEY
          valueFrom:
            configMapKeyRef:
              name: special-config
              key: special.type
      envFrom:                   #第二种导入方案
        - configMapRef: 
            name: env-config
  restartPolicy: Never
[root@k8s-master01 usage]# kubectl create -f dapi-test.pod.yaml 
pod/dapi-test-pod created
[root@k8s-master01 usage]# kubectl get pod
NAME            READY   STATUS      RESTARTS   AGE
dapi-test-pod   0/1     Completed   0          4s

#查看环境变量
[root@k8s-master01 usage]# kubectl logs dapi-test-pod
MYAPP_SVC_PORT_80_TCP_ADDR=10.98.57.156
KUBERNETES_PORT=tcp://10.96.0.1:443
KUBERNETES_SERVICE_PORT=443
MYAPP_SVC_PORT_80_TCP_PORT=80
HOSTNAME=dapi-test-pod
SHLVL=1
MYAPP_SVC_PORT_80_TCP_PROTO=tcp
HOME=/root
SPECIAL_TYPE_KEY=charm
MYAPP_SVC_PORT_80_TCP=tcp://10.98.57.156:80
NGINX_VERSION=1.12.2
KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
KUBERNETES_PORT_443_TCP_PORT=443
KUBERNETES_PORT_443_TCP_PROTO=tcp
MYAPP_SVC_SERVICE_HOST=10.98.57.156
SPECIAL_LEVEL_KEY=very
log_level=INFO
KUBERNETES_SERVICE_PORT_HTTPS=443
KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443
PWD=/
KUBERNETES_SERVICE_HOST=10.96.0.1
MYAPP_SVC_SERVICE_PORT=80
MYAPP_SVC_PORT=tcp://10.98.57.156:80

1.3.2、用 ConfigMap 设置命令行参数

[root@k8s-master01 usage]# cat dapi-test-pod-command.yaml 
apiVersion: v1
kind: ConfigMap
metadata:  
  name: special-config  
  namespace: default
data:  
  special.how: very
  special.type: charm
---
apiVersion: v1
kind: Pod
metadata:
  name: dapi-test-pod2
spec:
  containers:
    - name: test-container-command
      image: hub.dianchou.com/library/myapp:v1
      command: ["/bin/sh","-c","echo $(SPECIAL_LEVEL_KEY) $(SPECIAL_TYPE_KEY)"]
      env:                           #第一种导入方案
        - name: SPECIAL_LEVEL_KEY
          valueFrom:
            configMapKeyRef:
              name: special-config   #从哪个configMap导入
              key: special.how       #导入的是键名，就是将special.how键的键值赋予SPECIAL_LEVEL_KEY
        - name: SPECIAL_TYPE_KEY
          valueFrom:
            configMapKeyRef:
              name: special-config
              key: special.type
  restartPolicy: Never
[root@k8s-master01 usage]# kubectl create -f dapi-test-pod-command.yaml
configmap/special-config created
pod/dapi-test-pod2 created
[root@k8s-master01 usage]# kubectl get cm
NAME             DATA   AGE
special-config   2      4s
[root@k8s-master01 usage]# kubectl get pod
NAME             READY   STATUS      RESTARTS   AGE
dapi-test-pod2   0/1     Completed   0          10s
[root@k8s-master01 usage]# kubectl logs dapi-test-pod2
very charm

1.3.3、通过数据卷插件使用ConfigMap

在数据卷里面使用这个 ConfigMap，有不同的选项。最基本的就是将文件填入数据卷，在这个文件中，键就是文件名，键值就是文件内容

[root@k8s-master01 usage]# cat dapi-test-pod-volume.yaml
apiVersion: v1
kind: ConfigMap
metadata:  
  name: special-config  
  namespace: default
data:  
  special.how: very
  special.type: charm

---
apiVersion: v1
kind: Pod
metadata:
  name: dapi-test-pod3
spec:
  containers:
    - name: test-container
      image: hub.dianchou.com/library/myapp:v1
      command: ["/bin/sh","-c","sleep 600s"]
      volumeMounts:
      - name: config-volume
        mountPath: /etc/config
  volumes:
    - name: config-volume
      configMap:
        name: special-config
  restartPolicy: Never
[root@k8s-master01 usage]# kubectl create -f dapi-test-pod-volume.yaml 
configmap/special-config created
pod/dapi-test-pod3 created

[root@k8s-master01 usage]# kubectl get pod
NAME             READY   STATUS    RESTARTS   AGE
dapi-test-pod3   1/1     Running   0          6s
[root@k8s-master01 usage]# kubectl exec dapi-test-pod3 -it -- /bin/sh
/ # cd /etc/config
/etc/config # ls
special.how   special.type
/etc/config # cat special.how 
/etc/config # cat special.type 
charm/etc/config # 

kubernetes(五)--存储之configmap/secret/volume/Persistent Volume

原文：https://www.cnblogs.com/hujinzhong/p/12258966.html