k8s之ConfigMap

一、简介

ConfigMap是一个配置中心，可以配置Pod

二、ConfigMap

常见创建ConfigMap的类型如下：

• 命令创建
• 文件创建

1.命令行创建ConfigMap

# --from-literal 表示指定不同的key、value
[root@redis-cluser-01 configmap]# kubectl create configmap my-config --from-literal=key1=config1 --from-literal=key2=config2

# 查看cm
[root@redis-cluser-01 configmap]# kubectl get cm
NAME           DATA   AGE
my-config      2      62s

# 查看cm的具体值信息，可以看到键key1=config1 key2=config2
[root@redis-cluser-01 configmap]# kubectl describe cm my-config
Name:         my-config
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
key1:
----
config1
key2:
----
config2
Events:  <none>

2.文件创建ConfigMap

[root@redis-cluser-01 configmap]# vim www.conf
servcer {
    server_name myaqpp.magedu.com;
    listen 80;
    root /data/web/html/;
}


[root@redis-cluser-01 configmap]# kubectl create configmap nginx-www --from-file=./www.conf

# 查看cm
[root@redis-cluser-01 configmap]# kubectl get cm
NAME        DATA   AGE
nginx-www   1      26s


# 查看cm的具体值信息 可以看到键www.conf value值则为其文件内容
[root@redis-cluser-01 configmap]# kubectl describe cm nginx-www
Name:         nginx-www
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
www.conf:
----
servcer {
    server_name myaqpp.magedu.com;
    listen 80;
    root /data/web/html/;
}

Events:  <none>

三、ConfigMap配置至pod

配置了configmap后，因其本身就是一个配置中心，可以挂载至容器中让其更变为环境变量

1.envFrom配置环境变量

• 将cm中的key挂载至容器中

  “`shell

  <h1>创建cm</h1>

  [root@redis-cluser-01 tmp]# kubectl create configmap config-test –from-literal=my_key=my_value

  <h1>查看cm信息</h1>

  [root@redis-cluser-01 tmp]# kubectl describe cm config-test
  Name: config-test
  Namespace: default
  Labels: <none>
  Annotations: <none>

  <h1>Data</h1>

  my_key:</p></li>
  </ul>

  <hr />

  <p>my_value
  Events: <none>

  [root@redis-cluser-01 configmap]# vim pod-configmap.yml
  apiVersion: v1
  kind: Pod
  metadata:
  name: dapi-test-pod
  spec:
  containers:
  – name: test-container
  image: ikubernetes/myapp:v1
  envFrom:
  – configMapRef:
  name: config-test
  restartPolicy: Never

  # 查看容器的环境变量
  [root@redis-cluser-01 configmap]# kubectl exec -it dapi-test-pod printenv
  PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
  HOSTNAME=dapi-test-pod
  TERM=xterm
  my_key=my_value //环境变量已经加载进来
  KUBERNETES_SERVICE_PORT_HTTPS=443

  # 备注：此种方法比较宽泛，它统一将key value全部作为环境变量

  “`

  2.env配置环境变量

  • env配置环境变量可以细化某个cm的key，也可以同时指定多个cm的key

  [root@redis-cluser-01 configmap]# vim configmap-pod-2.yml
  apiVersion: v1
  kind: Pod
  metadata:
    name: dapi-test-pod-2
  spec:
    containers:
      - name: test-container
        image: ikubernetes/myapp:v1
        env:
          - name: KEY1
            valueFrom:
              configMapKeyRef:
                name: my-config
                key: key1
          - name: MY_KEY
            valueFrom:
              configMapKeyRef:
                name: config-test
                key: my_key
    restartPolicy: Never
  
  
  # 查看容器环境变量
  [root@redis-cluser-01 configmap]# kubectl exec -it dapi-test-pod-2 printenv
  PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
  HOSTNAME=dapi-test-pod-2
  TERM=xterm
  KEY1=config1
  MY_KEY=my_value
  ....
  

  四、ConfigMap语法

  • 创建configmap

  [root@redis-cluser-01 configmap]# vim configmap-1.yml
  apiVersion: v1
  kind: ConfigMap
  metadata:
    name: special-config
    namespace: default
  data:
    SPECIAL_LEVEL: very
    SPECIAL_TYPE: charm
  
  # 查看cm 
  root@redis-cluser-01 configmap]# kubectl describe cm special-config
  Name:         special-config
  Namespace:    default
  Labels:       <none>
  Annotations:  kubectl.kubernetes.io/last-applied-configuration:
                  {"apiVersion":"v1","data":{"SPECIAL_LEVEL":"very","SPECIAL_TYPE":"charm"},"kind":"ConfigMap","metadata":{"annotations":{},"name":"special-...
  
  Data
  ====
  SPECIAL_LEVEL:
  ----
  very
  SPECIAL_TYPE:
  ----
  charm
  Events:  <none>
  

  • pod加载configmap

    参考第三步骤