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k8s

code • 2022-4-18 • C • 阅读 34

k8s,第1张

1、ConfigMapp配置管理 1.1 ConfigMapp简介

ConfigMap是存储通用的配置变量的。

ConfigMap有点儿像一个统一的配置文件，使用户可以将分布式系统中用于不同模块的环境变量统一到一个对象中管理；而它与配置文件的区别在于它是存在集群的“环境”中的，并且支持K8s集群中所有通用的 *** 作调用方式。

而资源的使用者可以通过ConfigMap来存储这个资源的配置，这样需要访问这个资源的应用就可以同通过ConfigMap来引用这个资源。

相当通过创建Configmap封装资源配置。

configmap以一个或者多个key:value的形式保存在k8s系统中供应用使用，既可以用于表示一个变量的值（reg.westos:info)，也可以用于表示一个完整配置文件的内容


实验环境：

[root@server2 calico]# kubectl delete -f deny-nginx.yaml    删除之前的设置，保证实验环境的纯净
networkpolicy.networking.k8s.io "deny-nginx" deleted
networkpolicy.networking.k8s.io "acces-nginx" deleted
networkpolicy.networking.k8s.io "default-deny" deleted
networkpolicy.networking.k8s.io "deny-namespace" deleted
networkpolicy.networking.k8s.io "access-namespace" deleted
networkpolicy.networking.k8s.io "web-allow-external" deleted
[root@server2 ~]# kubectl delete ns test  删除test空间
1.2 、configmap创建方式 1.2.1 使用字面直创建： 
[root@server2 configmap]# kubectl create configmap my-config --from-literal=key1=config1 --from-literal=key2=config2   以键直形式存储
configmap/my-config created
[root@server2 configmap]# kubectl get cm
NAME               DATA   AGE
kube-root-ca.crt   1      13d
my-config          2      40s       创建成功
[root@server2 configmap]# kubectl describe cm my-config    查看创建的my-config   详细信息
Name:         my-config
Namespace:    default
Labels:       
Annotations:  

Data
====
key1:
----
config1
key2:
----
config2

BinaryData
====

Events:  
[root@server2 configmap]# kubectl get cm my-config  -o yaml   也可以将配置文件信息转换成yaml格式
apiVersion: v1
data:
  key1: config1
  key2: config2
kind: ConfigMap
metadata:
  creationTimestamp: "2022-03-29T13:52:47Z"
  name: my-config
  namespace: default
  resourceVersion: "738797"
  uid: 6223c5b0-88e0-4627-92a4-0b196718d848
1.2.2 使用文件创建： 
kubectl create configmap my-config-2 --from-file=/etc/resolv.conf   其中文件名就是key，文件内容就是直
[root@server2 configmap]# kubectl describe cm my-config-2  查看配置文件详细信息
Name:         my-config-2
Namespace:    default
Labels:       
Annotations:  

Data
====
resolv.conf:     这个就代表key
----
# Generated by NetworkManager
nameserver 114.114.114.114       文件里的内容就是键值

BinaryData
====

Events:  

如果想加多个，该怎么办？？
[root@server2 configmap]# mkdir test   创建一个目录，将多个文件放到目录里
[root@server2 configmap]# cp /etc/passwd test/   
[root@server2 configmap]# cp /etc/fstab  test/
[root@server2 configmap]# kubectl create configmap my-config-3 --from-file=test   此时test是个目录
1.2.3使用yaml文件创建： 
[root@server2 configmap]# vim cm1.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: cm1-config
data:
  db_host: "172.25.50.250"      键值
  db_port: "3306"     键值
[root@server2 configmap]# kubectl apply -f cm1.yaml   运行
configmap/cm1-config created
1.3、 如何使用configmap

1.3.1 通过环境变量的方式传递给pod 
[root@server2 configmap]# vim cm1.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: cm1-config
data:
  db_host: "172.25.50.250"      
  db_port: "3306"     
---
apiVersion: v1
kind: Pod
metadata:
  name: pod1
spec:
  containers:
    - name: pod1
      image: busybox
      command: ["/bin/sh", "-c", "env"]    表示在shell里执行打印变量
      env:             将定义的键值传入容器内
        - name: key1    此时key的名称被重新定义
          valueFrom:     值从哪来
            configMapKeyRef:   从configMapKeyRef做映射来
              name: cm1-config   从cm1-config来
              key: db_host   
        - name: key2   此时key的名称被重新定义
          valueFrom:
            configMapKeyRef:
              name: cm1-config
              key: db_port
  restartPolicy: Never
[root@server2 configmap]# kubectl apply -f cm1.yaml    运行
configmap/cm1-config unchanged
pod/pod1 created
[root@server2 configmap]# kubectl  logs pod1   查看日志的输出  



[root@server2 configmap]# kubectl delete pod pod1   删除pod1
pod "pod1" deleted
[root@server2 configmap]# vim cm1.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: cm1-config
data:
  db_host: "172.25.50.250"
  db_port: "3306"

---
apiVersion: v1
kind: Pod
metadata:
  name: pod1
spec:
  containers:
    - name: pod1
      image: busybox
      command: ["/bin/sh", "-c", "env"]
      envFrom: 
        - configMapRef:
            name: cm1-config    变量来自cm配置文件
 restartPolicy: Never
[root@server2 configmap]# kubectl apply -f cm1.yaml 
configmap/cm1-config unchanged
pod/pod1 created
[root@server2 configmap]# kubectl logs pod1   查看日志输出

1.3.2 通过在pod命令行里运行的方式 
[root@server2 configmap]# kubectl delete pod pod1  
pod "pod1" deleted
[root@server2 configmap]# vim cm1.yaml 
apiVersion: v1
kind: ConfigMap
metadata:
  name: cm1-config
data:
  db_host: "172.25.50.250"
  db_port: "3306"

---
apiVersion: v1
kind: Pod
metadata:
  name: pod1
spec:
  containers:
    - name: pod1
      image: busybox
      command: ["/bin/sh", "-c", "echo $(db_host) $(db_port)"]    直接在命令行里输出两个变量直，两个变量直取至于cm1-config
      envFrom:
        - configMapRef:
            name: cm1-config
  restartPolicy: Never
[root@server2 configmap]# kubectl apply -f cm1.yaml   运行
configmap/cm1-config unchanged
pod/pod1 created
[root@server2 configmap]# kubectl logs pod1
172.25.50.250 3306
1.3.3 通过数据卷使用congfigmap 
[root@server2 configmap]# kubectl delete pod pod1  删除pod1
pod "pod1" deleted
[root@server2 configmap]# vim pod.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: pod2
spec:
  containers:
    - name: pod2
      image: busybox
      command: ["/bin/sh", "-c", "cat /config/db_host"]
      volumeMounts:    卷挂载
      - name: config-volume    挂载的卷名字
        mountPath: /config    挂载到什么地方，路经没有可以自动建立
  volumes:    此参数表示卷的声明
    - name: config-volume
      configMap:    挂载的卷内容是映射configMap里的cm1-config 的内容
        name: cm1-config    
  restartPolicy: Never
[root@server2 configmap]# kubectl apply -f pod.yaml  运行
pod/pod2 created
[root@server2 configmap]# kubectl logs pod2
172.25.50.250
1.3.4 ConfigMap热更新 
[root@server2 configmap]# kubectl delete -f pod.yaml   删除
[root@server2 configmap]# vim pod.yaml   创建pod，一直运行
pod "pod2" deleted
apiVersion: v1
kind: Pod
metadata:
  name: pod2
spec:
  containers:
    - name: pod2
      image: busybox
      stdin: true
      tty: true      交互式，一直运行在后端
      volumeMounts:
      - name: config-volume
        mountPath: /config
  volumes:
    - name: config-volume
      configMap:
        name: cm1-config
[root@server2 configmap]# kubectl apply -f pod.yaml   运行
pod/pod2 created
 [root@server2 configmap]# kubectl get pod  查看，一直运行后端


[root@server2 configmap]# kubectl get cm   查看cm
NAME               DATA   AGE
cm1-config         2      14h
kube-root-ca.crt   1      13d
my-config          2      14h
my-config-2        1      14h
my-config-3        2      14h
[root@server2 configmap]# kubectl delete cm my-config  将不要的cm删除掉
configmap "my-config" deleted
[root@server2 configmap]# kubectl delete cm my-config-2
configmap "my-config-2" deleted
[root@server2 configmap]# kubectl delete cm my-config-3
configmap "my-config-3" deleted
[root@server2 configmap]# kubectl edit cm cm1-config   编辑cm1-config 


/ # cd config/
/config # ls
db_host  db_port
/config # cat db_port    已经变更了
8080
/config # cat db_host   已经变更了
172.25.50.100
[root@server2 configmap]# kubectl delete -f pod.yaml   删除
pod "pod2" deleted

[root@server2 configmap]# vim nginx.conf    创建nginx.conf文件，其中文件名为key，里面内容为值
server {
    listen       80;
    server_name  _;

    location / {
        root /usr/share/nginx/html;
        index  index.html index.htm;
    }
}
[root@server2 configmap]# kubectl create configmap nginxconf --from-file=nginx.conf   创建一个configmap的cm
configmap/nginxconf created
[root@server2 configmap]# kubectl describe cm nginxconf     查看cm为nginxconf配置文件详细信息
Name:         nginxconf
Namespace:    default
Labels:       
Annotations:  

Data
====
nginx.conf:
----
server {
    listen       80;
    server_name  _;

    location / {
        root /usr/share/nginx/html;
        index  index.html index.htm;
    }
}

[root@server2 configmap]# vim pod.yaml   编辑配置文件
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
        - name: nginx
          image: nginx
          volumeMounts:
          - name: config-volume
            mountPath: /etc/nginx/conf.d    路经为nginx 的 include目录，
      volumes:     表示将nginx.conf的内容挂接到/etc/nginx/conf.d目录里
        - name: config-volume
          configMap:
            name: nginxconf     
[root@server2 configmap]# kubectl apply -f pod.yaml   运行
deployment.apps/my-nginx created
[root@server2 configmap]# kubectl get pod


[root@server2 configmap]# kubectl exec -it my-nginx-7b84dc948c-9bvf7 -- bash   进入容器内部
root@my-nginx-7b84dc948c-9bvf7:/# cd /etc/nginx/
root@my-nginx-7b84dc948c-9bvf7:/etc/nginx# ls
conf.d		mime.types  nginx.conf	 uwsgi_params
fastcgi_params	modules     scgi_params
root@my-nginx-7b84dc948c-9bvf7:/etc/nginx# cd conf.d/
root@my-nginx-7b84dc948c-9bvf7:/etc/nginx/conf.d# ls
nginx.conf
root@my-nginx-7b84dc948c-9bvf7:/etc/nginx/conf.d# cat nginx.conf    下面就是挂接内容
server {
    listen       80;
    server_name  _;

    location / {
        root /usr/share/nginx/html;
        index  index.html index.htm;
    }
}
root@server2 configmap]# kubectl get pod -o wide  查看ip


[root@server2 configmap]# curl 10.244.141.232   访问，成功获取nginx默认页面



Welcome to nginx!