Kubernetes配置管理configMap

ConfigMap介绍

为什么要用configMap？

将配置文件和POD解耦

congiMap里的配置文件是如何存储的？

键值对
key:value

文件名:配置文件的内容

configMap支持的配置类型

直接定义的键值对
基于文件创建的键值对

configMap创建方式

命令行
资源配置清单

configMap的配置文件如何传递到POD里

变量传递
数据卷挂载

使用configMap的限制条件

1.ConfigMap必须在Pod之前创建，Pod才能引用他
2.ConfigMap受限于命名空间限制，只有处于同一个命名空间中的Pod才可以被引用

创建configMap

命令行创建configMap

[root@db01 tmp]# kubectl create configmap nginx-config --from-literal=nginx_port=80 --from-literal=server_name=blog.lw.com

--from-literal=  定义configMap中的变量

## 查看configMap
[root@db01 tmp]# kubectl get cm
NAME           DATA   AGE
nginx-config   2      43s

## 详细信息
[root@db01 tmp]# kubectl describe cm nginx-config

## 清单引用configMap
apiVersion: v1
kind: Pod
metadata:
  name: nginx-cm
spec:
  containers:

  - name: nginx-pod
    image: nginx:1.14.0
    imagePullPolicy: IfNotPresent
    ports:
    - name: http
      containerPort: 80
      env:
    - name: NGINX_PORT
      valueFrom:
        configMapKeyRef:
          name: nginx-config
          key: nginx_port
    - name: SERVER_NAME
      valueFrom:
        configMapKeyRef:
          name: nginx-config
          key: server_name

查看pod是否引入了变量

[root@node1~lconfimap]# kubectL exec-it nginx-cm/bin/bash
root@nginx-cm：~# echo${NGINX_PORT}
80
Root@nginx-cm：~# echo${SERVER_NAME}
blog.lw.com

注意:

变量传递的形式，修改conf Map的配置，POD内并不会生效因为变量只有在创建POD的时候才会引用生效，POD一旦创建好，环境变量就不变了

使用文件创建configmap

[root@db01 config-map]# cat www.conf 
server {
        listen       80;
        server_name  www.lw.com;
        location / {
            root   /usr/share/nginx/html/www;
            index  index.html index.htm;
        }
}

# 命令行创建configmap资源
[root@db01 config-map]# kubectl create configmap nginx-www --from-file=www.conf=./www.conf 
configmap/nginx-www created

[root@db01 config-map]# kubectl get cm
NAME           DATA   AGE
nginx-config   2      47m
nginx-www      1      49s

[root@db01 config-map]# kubectl describe cm nginx-www

# 清单引用configmap
vim nginx-cm-volume.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: nginx-cm-01
spec:
  volumes:
  - name: configmap-data
    configMap:
     name: nginx-www
     items:
     - key: www.conf
       path: www.conf
  containers:
  - name: nginx-pod
    image: nginx:alpine
    imagePullPolicy: IfNotPresent
    ports:
    - name: http
      containerPort: 80
    volumeMounts:
    - name: configmap-data
      mountPath: /etc/nginx/conf.d/

测试效果

1.进到容器内查看文件

kubectl exec -it nginx-cm /bin/bash
cat /etc/nginx/conf.d/vww . conf

2.动态修改

configMap kubectl edit cm nginx-cm-01

3.再次进入容器内观察配置会不会自动更新

cat /etc/nginx/conf.d/wwnw . conf
nginx -T

资源清单创建configMap

[root@db01 config-map]# cat nginx-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: ngx-config
data:
  www.conf: |
    server {
            listen       80;
            server_name  www.lw.com;
            location / {
                root   /usr/share/nginx/html/www;
                index  index.html index.htm;
            }
        }
  blog.conf: |
    server {
            listen       80;
            server_name  blog.lw.com;
            location / {
                root   /usr/share/nginx/html/blog;
                index  index.html index.htm;
            }
        }

[root@db01 config-map]# kubectl apply -f nginx-configmap.yaml

[root@db01 config-map]# kubectl get cm
NAME           DATA   AGE
nginx-config   2      70m
nginx-www      1      24m
ngx-config     2      15s

[root@db01 config-map]# kubectl describe cm ngx-config

# 创建pod资源清单并引用configmap
[root@db01 config-map]# cat nginx-dp.yaml
apiVersion: apps/v1
kind: Deployment
metadata: 
  name: nginx-dp
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx-cm
  template:
    metadata:
      name: nginx-pod
      labels:
        app: nginx-cm
    spec: 
      volumes:
      - name: cm-data
        configMap:
         name: ngx-config
         items: 
         - key: www.conf
           path: www.conf
         - key: blog.conf
           path: blog.conf
      containers:
      - name: nginx-pod
        image: nginx:alpine
        imagePullPolicy: IfNotPresent
        ports:
        - name: http 
          containerPort: 80
        volumeMounts:
        - name: cm-data
          mountPath: /etc/nginx/conf.d/

[root@db01 config-map]# vim clusterip.yaml
apiVersion: v1
kind: Service
metadata:
  name: ngx-svc
spec:
  selector:
    app: ngx-cm
  ports:
  - name: http
    port: 80
    protocol: TCP
    targetPort: 80
  type: ClusterIP

[root@db01 config-map]# cat nginx-ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ngx-ingress
spec:
  rules:
  - host: www.lw.com
    http:
      paths:
      - path: /
        pathType: ImplementationSpecific
        backend:
          service:
            name: ngx-svc
            port:
              number: 80

  - host: blog.lw.com
    http:
      paths:
      - path: /
        pathType: ImplementationSpecific
        backend:
          service:
            name: ngx-svc
            port:
              number: 80