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文章目录
- 前言
- 一、ConfigMap介绍
- 二、ConfigMap创建
-
- [2.1 通过命令创建](#2.1 通过命令创建)
- [2.2 通过yaml文件创建](#2.2 通过yaml文件创建)
- 三、ConfigMap使用
前言
在Kubernetes集群中，配置与应用解耦是云原生部署的关键实践。硬编码配置会导致镜像臃肿、环境适配困难，而ConfigMap正是解决这一问题的核心资源。它以键值对存储非敏感配置，支持环境变量、配置文件挂载等多种注入方式，实现配置集中管理与动态更新。本文将从原理、创建、使用到最佳实践，全面讲解ConfigMap的落地方法
一、ConfigMap介绍
ConfigMap 是 Kubernetes 中用于 存储非敏感配置信息 的核心资源，核心作用是 保存不需要加密的，应用所需的配置信息 ，让同一镜像可适配开发、测试、生产等不同环境，无需重新打包
它以 键值对 形式存放配置，可存储配置文件片段、环境变量、命令行参数等内容。创建后能通过环境变量注入、挂载为配置文件、命令行参数等方式供 Pod 使用，实现配置集中管理、灵活变更与统一分发，避免硬编码带来的维护难题，是云原生应用标准化配置的基础组件
二、ConfigMap创建
2.1 通过命令创建
yaml
## 1. 直接在命令行中指定configmap
root@k8s-master1:~# kubectl create configmap test-configmap1 --from-literal=user=amdin --from-literal=pass=1234
# kube-root-ca.crt存储了k8s集群的根CA证书公钥，用于集群内的身份认证、加密通信
# K8s会自动把这个ConfigMap挂载到每一个新建的Pod里，让容器内的应用可以信任集群的证书，实现安全访问API Server等组件
root@k8s-master1:~# kubectl get configmap
NAME DATA AGE
kube-root-ca.crt 1 15d # k8s集群自动创建的系统内置ConfigMap
test-configmap1 2 7s
root@k8s-master1:~# kubectl get configmap test-configmap1 -o yaml
apiVersion: v1
data:
pass: "1234"
user: amdin
kind: ConfigMap
metadata:
creationTimestamp: "2026-04-23T06:11:32Z"
name: test-configmap1
namespace: default
resourceVersion: "611852"
uid: 5f136be4-bbb7-4f4e-8f4e-86e3fc675eab
yaml
## 2. 将一个配置文件创建为configmap
root@k8s-master1:~# mkdir -p /k8s-test/configmap
root@k8s-master1:~# cd /k8s-test/configmap
root@k8s-master1:/k8s-test/configmap# vim app.properties
server.port=8080
database.url=jdbc:mysql://mysql:3306/test
redis.host=redis-service
log.level=info
root@k8s-master1:/k8s-test/configmap# kubectl create configmap test-configmap2 --from-file=app.properties
root@k8s-master1:/k8s-test/configmap# kubectl get configmap
NAME DATA AGE
kube-root-ca.crt 1 15d
test-configmap1 2 11m
test-configmap2 1 5s
root@k8s-master1:/k8s-test/configmap# kubectl get configmap test-configmap2 -o yaml # 查看详细信息
apiVersion: v1
data:
app.properties: |
server.port=8080
database.url=jdbc:mysql://mysql:3306/test
redis.host=redis-service
log.level=info
kind: ConfigMap
metadata:
creationTimestamp: "2026-04-23T06:23:19Z"
name: test-configmap2
namespace: default
resourceVersion: "613264"
uid: f1d62b11-94e4-407e-aa18-4a50377cfe4f
root@k8s-master1:/k8s-test/configmap#
yaml
## 3. 将目录下的所有配置文件创建为configmap
root@k8s-master1:/k8s-test/configmap# mkdir config
root@k8s-master1:/k8s-test/configmap# echo 1111 > config/config1
root@k8s-master1:/k8s-test/configmap# echo 2222 > config/config2
root@k8s-master1:/k8s-test/configmap# kubectl create configmap test-configmap3 --from-file=config
configmap/test-configmap3 created
root@k8s-master1:/k8s-test/configmap# kubectl get configmap
NAME DATA AGE
kube-root-ca.crt 1 15d
test-configmap1 2 30m
test-configmap2 1 18m
test-configmap3 2 8s
root@k8s-master1:/k8s-test/configmap# kubectl get configmap test-configmap3 -o yaml
apiVersion: v1
data:
config1: |
1111
config2: |
2222
kind: ConfigMap
metadata:
creationTimestamp: "2026-04-23T06:41:59Z"
name: test-configmap3
namespace: default
resourceVersion: "615507"
uid: 137fbc97-3458-4279-84f3-97178a6550292.2 通过yaml文件创建
yaml
root@k8s-master1:/k8s-test/configmap# vim mysql-nginx.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql-nginx
namespace: default
data:
# MySQL 配置
mysql.cnf: |
[mysqld]
datadir=/var/lib/mysql
socket=/var/run/mysqld/mysqld.sock
port=3306
character-set-server=utf8mb4
collation-server=utf8mb4_unicode_ci
max_connections=200
wait_timeout=600
bind-address=0.0.0.0
# Nginx 配置
nginx.conf: |
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;
events {
worker_connections 1024;
}
http {
include /etc/nginx/mime.types;
default_type application/octet-stream;
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
keepalive_timeout 65;
server {
listen 80;
server_name localhost;
root /usr/share/nginx/html;
index index.html index.htm;
location / {
try_files $uri $uri/ /index.html;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root /usr/share/nginx/html;
}
}
}
root@k8s-master1:/k8s-test/configmap# kubectl apply -f mysql-nginx.yaml
configmap/mysql-nginx created
root@k8s-master1:/k8s-test/configmap# kubectl get configmap
NAME DATA AGE
kube-root-ca.crt 1 15d
mysql-nginx 2 5s
test-configmap1 2 35m
test-configmap2 1 23m
test-configmap3 2 5m17s
root@k8s-master1:/k8s-test/configmap#
root@k8s-master1:/k8s-test/configmap# kubectl get configmap mysql-nginx -o yaml三、ConfigMap使用
3.1 环境变量引用
yaml
## 我这先删除一下没用的configmap
root@k8s-master1:/k8s-test/configmap# kubectl get configmap
NAME DATA AGE
kube-root-ca.crt 1 15d
mysql-nginx 2 30m
test-configmap1 2 65m
test-configmap2 1 54m
test-configmap3 2 35m
root@k8s-master1:/k8s-test/configmap# kubectl delete configmap test-configmap1 test-configmap2 test-configmap3
yaml
## 1. 创建一个configmap
root@k8s-master1:/k8s-test/configmap# vim configmap1.yaml
---
apiVersion: v1
kind: ConfigMap
metadata:
name: test-config4
namespace: default
data:
name: jack
sex: man
age: ten
my.cnf: |
[mysqld]
datadir=/var/lib/mysql
socket=/var/run/mysqld/mysqld.sock
yaml
## 2. 创建pod，用环境变量引用configmap中的部分key
root@k8s-master1:/k8s-test/configmap# kubectl apply -f configmap1.yaml
root@k8s-master1:/k8s-test/configmap# kubectl get configmap
NAME DATA AGE
kube-root-ca.crt 1 15d
mysql-nginx 2 31m
test-config4 4 4s
root@k8s-master1:/k8s-test/configmap# vim pod.yaml
---
apiVersion: v1
kind: Pod
metadata:
name: test-pod
spec:
containers:
- name: test-pod
image: nginx:1.24
env: # 专门在容器里面设置变量的关键字
- name: TEST_NAME # 容器里设置的新变量的名字
valueFrom:
configMapKeyRef:
name: test-config4 # 引用哪个configmap
key: name # 引用这个configmap中的哪个key
- name: TEST_AGE
valueFrom:
configMapKeyRef:
name: test-config4
key: age
root@k8s-master1:/k8s-test/configmap# kubectl apply -f pod.yaml
root@k8s-master1:/k8s-test/configmap# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-harbor 1/1 Running 1 (77m ago) 158m
test-pod 1/1 Running 0 4s
root@k8s-master1:/k8s-test/configmap# kubectl exec -it test-pod /bin/bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
root@test-pod:/# echo $TEST_NAME
jack
root@test-pod:/# echo $TEST_AGE
ten
root@test-pod:/# exit
exit
root@k8s-master1:/k8s-test/configmap#
yaml
## 3. 创建pod，用环境变量引用configmap中的所有key
root@k8s-master1:/k8s-test/configmap# vim pod2.yaml
---
apiVersion: v1
kind: Pod
metadata:
name: test-pod2
spec:
containers:
- name: test-pod2
image: nginx:1.24
envFrom:
- configMapRef:
name: test-config4
root@k8s-master1:/k8s-test/configmap# kubectl apply -f pod2.yaml
root@k8s-master1:/k8s-test/configmap# kubectl exec -it test-pod2 /bin/bash进入容器内部，发现所有的key已经自动变成环境变量
3.2 卷挂载
yaml
root@k8s-master1:/k8s-test/configmap# vim volupod.yaml
---
apiVersion: v1
kind: Pod
metadata:
name: test-pod3
spec:
containers:
- name: test-pod3
image: nginx:1.24
volumeMounts:
- name: test-volume # 挂载卷test-volume
mountPath: "/tmp/volume" # 把它挂载到容器内的/tmp/volume目录下
volumes:
- name: test-volume # 定义一个名为test-volume的卷
configMap:
name: test-config4 # test-volume卷的内容来自test-config4
root@k8s-master1:/k8s-test/configmap# kubectl apply -f volupod.yaml
root@k8s-master1:/k8s-test/configmap# kubectl exec -it test-pod3 /bin/bash # 进入容器
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
root@test-pod3:/# ls /tmp/volume/ # test-config4中的每个key都变成了文件，文件中存的是key对应的值
age my.cnf name sex
root@test-pod3:/# cat /tmp/volume/my.cnf
[mysqld]
datadir=/var/lib/mysql
socket=/var/run/mysqld/mysqld.sock
root@test-pod3:/# cat /tmp/volume/name
jackroot@test-pod3:/# cat /tmp/volume/age
tenroot@test-pod3:/# cat /tmp/volume/sex
manroot@test-pod3:/# exit
exit3.3 subPath参数
subPath：挂载文件用的，在 volumeMounts 下面，只挂载单个文件，不覆盖整个目录，不支持热更新用了 subPath → 不支持热更新
如果你要 覆盖配置文件（nginx.conf、my.cnf）→ 必须用 subPath，接受不能热更新，例如主配置文件
如果你要 挂载配置目录→ 不用 subPath，可以热更新，例如子配置文件
yaml
## 例：创建mysql和nginx pod，引用mysql-nginx configmap配置文件
root@k8s-master1:/k8s-test/configmap# kubectl get cm # 查看当前的configmap
NAME DATA AGE
kube-root-ca.crt 1 15d
mysql-nginx 2 13m
## 1. 创建一个secret存放mysql的登录密码
root@k8s-master1:/k8s-test/configmap# echo -n "Abc@123" > password.txt
root@k8s-master1:/k8s-test/configmap# kubectl create secret generic mysql-pass --from-file=./password.txt
yaml
## 3. 创建mysql和nginx的pod
root@k8s-master1:/k8s-test/configmap# vim mysql-nginx-pod.yaml
---
apiVersion: v1
kind: Pod
metadata:
name: mysql
spec:
containers:
- name: mysql
image: mysql:5.7
# 环境变量
env:
# 环境变量名：MYSQL_ROOT_PASSWORD（mysql的root密码）
- name: MYSQL_ROOT_PASSWORD
valueFrom:
# 值从secret里提取
secretKeyRef:
# 来自哪个secret
name: mysql-pass
# 取该secret里的哪个键值
key: password.txt
# 卷挂载：把外部卷挂到容器内部路径
volumeMounts:
# 使用一个名为mysql的卷
- name: mysql
# 容器内的挂载目标文件
mountPath: /etc/my.cnf
# 只挂载卷里的my.cnf这一个文件，不覆盖整个目录，如果不加subPath容器不能正常启动
subPath: my.cnf
# 定义Pod级别的数据卷
volumes:
# 定义一个卷的名字叫mysql
- name: mysql
configMap:
# 使用名为mysql-nginx的configmap
name: mysql-nginx
items:
# cm里的key是mysql.cnf
- key: mysql.cnf
# 映射到卷里的文件名叫my.cnf
path: my.cnf
---
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- name: nginx
image: nginx:1.24
volumeMounts:
- name: nginx
mountPath: /etc/nginx/nginx.conf
subPath: nginx.conf
volumes:
- name: nginx
configMap:
name: mysql-nginx
items:
- key: nginx.conf
path: nginx.conf
yaml
## 4. 运行pod
root@k8s-master1:/k8s-test/configmap# kubectl apply -f mysql-nginx-pod.yaml
root@k8s-master1:/k8s-test/configmap# kubectl get pod
NAME READY STATUS RESTARTS AGE
mysql 1/1 Running 0 59s
nginx 1/1 Running 0 10s
yaml
## 5. 进入nginx pod内部，看看nginx能否正常访问
root@k8s-master1:/k8s-test/configmap# kubectl exec -it nginx /bin/bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
root@nginx:/# curl localhost
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
root@nginx:/# exit
exit
yaml
## 6. 进入mysql pod中，看看能否登录mysql
root@k8s-master1:/k8s-test/configmap# kubectl exec -it mysql /bin/bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
bash-4.2# mysql -uroot -p'Abc@123' # 登录成功
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.44 MySQL Community Server (GPL)
Copyright (c) 2000, 2023, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> exit
Bye
bash-4.2# exit
exit3.4 configmap的热更新
不热更新案例
验证subPath支不支持热更新
yaml
## 例：
root@k8s-master1:/k8s-test/configmap# vim mysql-nginx.yaml
worker_processes 2; # 更改这一行，之前是worker_processes auto;
root@k8s-master1:/k8s-test/configmap# kubectl apply -f mysql-nginx.yaml
root@k8s-master1:/k8s-test/configmap# kubectl get configmap mysql-nginx -o yaml
由此可知，subPath不支持热更新
热更新案例
想要支持热更新，需要用yaml文件方式创建configmap，并且不能使用subPath参数，并且需要卷挂载configmap才能实现热更新
yaml
# 例，热更新案例
## 1. 创建一个nginx的configmap，里面存放网页配置
root@k8s-master1:/k8s-test/configmap# vim nginx-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: nginx
namespace: default
data:
# Nginx 页面
index.html: |
welcome nginx
hello
root@k8s-master1:/k8s-test/configmap# kubectl apply -f nginx-configmap.yaml
## 2. 创建nginx pod，用卷挂载的方式引用nginx configmap
root@k8s-master1:/k8s-test/configmap# vim nginx-pod.yaml
---
apiVersion: v1
kind: Pod
metadata:
name: nginx-pod
spec:
hostNetwork: true
containers:
- name: nginx
image: nginx:1.24
ports:
- containerPort: 80
volumeMounts:
- mountPath: /usr/share/nginx/html
name: index
volumes:
- name: index
configMap:
name: nginx
items:
- key: index.html
path: index.html
root@k8s-master1:/k8s-test/configmap# kubectl apply -f nginx-pod.yaml
root@k8s-master1:/k8s-test/configmap# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-pod 1/1 Running 0 7s
## 3. 访问页面，看是否挂载成功
root@k8s-master1:/k8s-test/configmap# curl 192.168.13.139:80
welcome nginx
hello
yaml
## 4. 更改nginx configmap，看看nginx pod的页面是否会改变
root@k8s-master1:/k8s-test/configmap# vim nginx-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: nginx
namespace: default
data:
# Nginx 页面
index.html: |
welcome nginx # 删除了最后一行
root@k8s-master1:/k8s-test/configmap# kubectl apply -f nginx-configmap.yaml
## 5. 重新访问页面，由于某种延迟过几秒后会刷新出新的页面
root@k8s-master1:/k8s-test/configmap# curl 192.168.13.139:80
welcome nginx注：
文中若有疏漏，欢迎大家指正赐教。
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