Kubernetes 之 ConfigMap

ConfigMap 定义

ConfigMap 是一种 API 对象，用来将非机密性的数据保存到键值对中。使用时， Pod 可以将其用作环境变量、命令行参数或者存储卷中的配置文件。通过使用 ConfigMap 可以将你的配置数据和应用程序代码分开。

ConfigMap 的创建

直接在命令行中指定 Config 参数创建，通过--from-literal指定参数

shell 复制代码

kubectl create configmap mysql-config --from-literal=MYSQL_PORT=3306 --from-literal=MYSQL_ROOT_PASSWORD=passwd

root@k8s-master1:~# kubectl get cm/mysql-config
NAME           DATA   AGE
mysql-config   2      10s
root@k8s-master1:~# kubectl describe cm/mysql-config
Name:         mysql-config
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
MYSQL_PORT:
----
3306
MYSQL_ROOT_PASSWORD:
----
passwd

BinaryData
====

通过指定文件创建，先创建一个nginx.conf文件，然后通过--from-file指令创建

worker_processes  1;

events {
    worker_connections  1024;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    server {
        listen       80;
        server_name  localhost;

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

shell 复制代码

kubectl create configmap nginx-config --from-file nginx/nginx.conf

root@k8s-master1:~# kubectl describe cm/nginx-config
Name:         nginx-config
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
nginx.conf:
----
worker_processes  1;\r
\r
events {\r
    worker_connections  1024;\r
}\r
\r
http {\r
    include       /etc/nginx/mime.types;\r
    default_type  application/octet-stream;\r
\r
    server {\r
        listen       80;\r
        server_name  localhost;\r
\r
        location / {\r
            root   /usr/share/nginx/html;\r
            index  index.html index.htm;\r
        }\r
    }\r
}

BinaryData
====

Events:  <none>

通过指定文件夹创建，先创建一个nginx文件夹，再创建一个index.html文件,然后把index.html文件和nginx.conf文件移动到nginx文件夹下，然后通过--from-file指令创建

html 复制代码

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Nginx Test</title>
</head>
<body>
Hello World
</body>
</html>

shell 复制代码

kubectl create configmap nginx-config --from-file nginx/

root@k8s-master1:~# kubectl describe cm/nginx-config
Name:         nginx-config
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
index.html:
----
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Nginx Test</title>
</head>
<body>
Hello World
</body>
</html>
nginx.conf:
----
worker_processes  1;\r
\r
events {\r
    worker_connections  1024;\r
}\r
\r
http {\r
    include       /etc/nginx/mime.types;\r
    default_type  application/octet-stream;\r
\r
    server {\r
        listen       80;\r
        server_name  localhost;\r
\r
        location / {\r
            root   /usr/share/nginx/html;\r
            index  index.html index.htm;\r
        }\r
    }\r
}

BinaryData
====

通过 yaml 文件的方式创建

shell 复制代码

kubectl create -f configmap-mysql-nginx.yaml

root@k8s-master1:~# kubectl describe cm/configmap-mysql-nginx
Name:         configmap-mysql-nginx
Namespace:    default
Labels:       app=configmap-mysql-nginx
Annotations:  <none>

Data
====
MYSQL_PORT:
----
3306
MYSQL_ROOT_PASSWORD:
----
passwd
index.html:
----
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Nginx Test</title>
</head>
<body>
  Hello World
</body>
</html>

nginx.conf:
----
worker_processes  1;

events {
  worker_connections  1024;
}

http {
  include       /etc/nginx/mime.types;
  default_type  application/octet-stream;

  server {
    listen       80;
    server_name  localhost;

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


BinaryData
====

Events:  <none>

ConfigMap 使用

yaml 复制代码

apiVersion: v1
kind: Pod
metadata:
  name: pod-configmap
spec:
  containers:
    - name: configmap-test
      image: busybox
      command: [ "/bin/sh", "-c", "sleep 3600" ]
      env:
      - name: MYSQL_PORT
        valueFrom:
          configMapKeyRef:
            name: configmap-mysql-nginx
            key: MYSQL_PORT
      - name: MYSQL_ROOT_PASSWORD
        valueFrom:
          configMapKeyRef:
            name: configmap-mysql-nginx
            key: MYSQL_ROOT_PASSWORD
      envFrom:
        - configMapRef:
            name: service-config
      volumeMounts:
        - name: volume-configmap
          mountPath: /etc/nginx
  volumes:
    - name: volume-configmap
      configMap:
        name: configmap-mysql-nginx
  restartPolicy: Never

root@k8s-master1:~# kubectl exec -it pod-configmap -- /bin/sh
/ # env
KUBERNETES_SERVICE_PORT=443
KUBERNETES_PORT=tcp://10.96.0.1:443
HOSTNAME=pod-configmap
SHLVL=1
HOME=/root
MYSQL_ROOT_PASSWORD=passwd
SERVICE_NAME=configmap-test
TERM=xterm
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
MYSQL_PORT=3306
KUBERNETES_SERVICE_PORT_HTTPS=443
KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443
KUBERNETES_SERVICE_HOST=10.96.0.1
PWD=/
/ # ls -al /etc/nginx/
total 12
drwxrwxrwx    3 root     root          4096 Jun  1 02:16 .
drwxr-xr-x    1 root     root          4096 Jun  1 02:16 ..
drwxr-xr-x    2 root     root          4096 Jun  1 02:16 ..2024_06_01_02_16_52.4048032045
lrwxrwxrwx    1 root     root            32 Jun  1 02:16 ..data -> ..2024_06_01_02_16_52.4048032045
lrwxrwxrwx    1 root     root            17 Jun  1 02:16 MYSQL_PORT -> ..data/MYSQL_PORT
lrwxrwxrwx    1 root     root            26 Jun  1 02:16 MYSQL_ROOT_PASSWORD -> ..data/MYSQL_ROOT_PASSWORD
lrwxrwxrwx    1 root     root            17 Jun  1 02:16 index.html -> ..data/index.html
lrwxrwxrwx    1 root     root            17 Jun  1 02:16 nginx.conf -> ..data/nginx.conf
/ #