【容器应用系列教程】Kubernetes配置映射ConfigMap
一、关于ConfigMap
以键值对存储业务的配置数据(密码、配置文件内容)
二、创建并使用ConfigMap
1.在ConfigMap通过键值对的方式定义
[root@k8s-master wordpress]# vim config-db.yml
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql-config
namespace: wordpress
data:
db_password: redhat
db_name: jiaowu
[root@k8s-master wordpress]# kubectl create -f config-db.yml
configmap/mysql-config created
查看ConfigMap
[root@k8s-master wordpress]# kubectl get cm -n wordpress
NAME DATA AGE
kube-root-ca.crt 1 3h19m
mysql-config 2 46s
查看ConfigMap的详细信息
[root@k8s-master wordpress]# kubectl describe cm mysql-config -n wordpress
Name: mysql-config
Namespace: wordpress
Labels: <none>
Annotations: <none>
Data
====
db_name: #键
----
jiaowu #对应的值
db_password: #键
----
redhat #对应的值
Events: <none>
[root@k8s-master wordpress]#
使用刚刚存的ConfigMap创建数据库Pod
[root@k8s-master wordpress]# vim config-mysql.yml
apiVersion: apps/v1
kind: Deployment
metadata:
name: wp-mysql
namespace: wordpress
spec:
replicas: 1
selector:
matchLabels:
app: wp-mysql
strategy:
type: RollingUpdate
rollingUpdate:
maxSurge: 1
maxUnavailable: 0
template:
metadata:
labels:
app: wp-mysql
spec:
containers:
- name: wp-mysql
image: mysql:5.7
imagePullPolicy: IfNotPresent
ports:
- containerPort: 3306
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
configMapKeyRef: #配置变量取自ConfigMap
name: mysql-config #刚刚创建的ConfigMap服务的名字
key: db_password #对应的键
- name: MYSQL_DATABASE
valueFrom:
configMapKeyRef:
name: mysql-config
key: db_name
resources:
requests:
memory: "1G"
cpu: "1"
limits:
memory: "2G"
cpu: "2"
---
apiVersion: v1
kind: Service
metadata:
name: wp-mysql
namespace: wordpress
spec:
ports:
- port: 3306
selector:
app: wp-mysql
[root@k8s-master wordpress]# kubectl create -f config-mysql.yml
deployment.apps/wp-mysql created
service/wp-mysql created
[root@k8s-master wordpress]# kubectl get pods -n wordpress
NAME READY STATUS RESTARTS AGE
wp-mysql-55858fbc65-m8vnl 1/1 Running 0 82s
进入容器内部验证
[root@k8s-master wordpress]# kubectl exec -it wp-mysql-55858fbc65-m8vnl -n wordpress -- bash
bash-4.2# mysql -uroot -predhat
mysql> #密码正确
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| jiaowu | #jiaowu库
| mysql |
| performance_schema |
| sys |
+--------------------+
5 rows in set (0.00 sec)
2.在ConfigMap中定义配置文件
[root@k8s-master wordpress]# vim config-db.yml
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql-config
namespace: wordpress
data:
db_password: redhat
db_name: jiaowu
my.cnf: | #定义配置文件名
[mysqld]
server_id=10
log_bin=master
gtid_mode=on #开启事务
enforce_gtid_consistency=true
collation-server = utf8_general_ci
character-set-server = utf8 #定义默认创建库的字符集为utf8
[root@k8s-master wordpress]# kubectl apply -f config-db.yml
查看ConfigMap详细信息
[root@k8s-master wordpress]# kubectl describe cm mysql-config -n wordpress
Name: mysql-config
Namespace: wordpress
Labels: <none>
Annotations: <none>
Data
====
db_name:
----
jiaowu
db_password:
----
redhat
my.cnf:
----
[mysqld]
server_id=10
log_bin=master
gtid_mode=on
enforce_gtid_consistency=true
collation-server = utf8_general_ci
character-set-server = utf8
挂载配置文件，创建Pod
[root@k8s-master wordpress]# vim config-mysql.yml
apiVersion: apps/v1
kind: Deployment
metadata:
name: wp-mysql
namespace: wordpress
spec:
replicas: 1
selector:
matchLabels:
app: wp-mysql
strategy:
type: RollingUpdate
rollingUpdate:
maxSurge: 1
maxUnavailable: 0
template:
metadata:
labels:
app: wp-mysql
spec:
containers:
- name: wp-mysql
image: mysql:5.7
imagePullPolicy: IfNotPresent
ports:
- containerPort: 3306
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
configMapKeyRef:
name: mysql-config
key: db_password
resources:
requests:
memory: "1G"
cpu: "1"
limits:
memory: "2G"
cpu: "2"
volumeMounts: #挂载数据卷
- name: config-mysql-volume #挂载自己定义的数据卷名
mountPath: "/etc/mysql/conf.d" #挂载路径
readOnly: true #开启只读
volumes:
- name: config-mysql-volume #创建一个数据卷名
projected:
sources:
- configMap: #定义ConfigMap类型
name: mysql-config #指定数据卷挂载到哪个ConfigMap上
---
apiVersion: v1
kind: Service
metadata:
name: wp-mysql
namespace: wordpress
spec:
ports:
- port: 3306
selector:
app: wp-mysql
[root@k8s-master wordpress]# kubectl create -f config-mysql.yml
deployment.apps/wp-mysql created
service/wp-mysql created
[root@k8s-master wordpress]# kubectl get pods -n wordpress
NAME READY STATUS RESTARTS AGE
wp-mysql-68b5d74d89-gr25n 1/1 Running 0 4s
进入容器内部检查
[root@k8s-master wordpress]# kubectl exec -it wp-mysql-68b5d74d89-gr25n -n wordpress -- bash
bash-4.2# mysql -uroot -predhat
mysql> show master status\G; #二进制日志是开启状态
*************************** 1. row ***************************
File: master.000003
Position: 194
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set: 799fd813-0b74-11ee-95c8-6e94f7388cb8:1-5
1 row in set (0.00 sec)
mysql> create database AA;
Query OK, 1 row affected (0.00 sec)
mysql> select schema_name,default_character_set_name from information_schema.schemata;
+--------------------+----------------------------+
| schema_name | default_character_set_name |
+--------------------+----------------------------+
| information_schema | utf8 |
| AA | utf8 | #所有库都是utf8字符集
| mysql | utf8 |
| performance_schema | utf8 |
| sys | utf8 |
+--------------------+----------------------------+
5 rows in set (0.00 sec)