396 lines
9.9 KiB
Markdown
396 lines
9.9 KiB
Markdown
<h1><center>Kubernetes资源对象ConfigMap</center></h1>
|
||
|
||
|
||
|
||
------
|
||
|
||
## 一：ConfigMap
|
||
|
||
用来存储配置文件的kubernetes资源对象，所有的配置内容都存储在etcd中；ConfigMap与 Secret 类似
|
||
|
||
#### 1.ConfigMap与 Secret 的区别
|
||
|
||
ConfigMap 保存的是不需要加密的、应用所需的配置信息
|
||
|
||
ConfigMap 的用法几乎与 Secret 完全相同：可以使用 kubectl create configmap 从文件或者目录创建 ConfigMap，也可以直接编写 ConfigMap 对象的 YAML 文件
|
||
|
||
#### 2.创建ConfigMap
|
||
|
||
方式1：通过直接在命令行中指定configmap参数创建，即--from-literal
|
||
|
||
方式2：通过指定文件创建，即将一个配置文件创建为一个ConfigMap--from-file=<文件>
|
||
|
||
方式3：通过指定目录创建，即将一个目录下的所有配置文件创建为一个ConfigMap，--from-file=<目录>
|
||
|
||
方式4：事先写好标准的configmap的yaml文件，然后kubectl create -f 创建
|
||
|
||
通过命令行参数--from-literal创建：
|
||
|
||
创建命令
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl create configmap test-config1 --from-literal=db.host=10.5.10.116 --from-literal=db.port='3306'
|
||
configmap/test-config1 created
|
||
```
|
||
|
||
结果如下面的data内容所示
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl get configmap test-config1 -o yaml
|
||
apiVersion: v1
|
||
data:
|
||
db.host: 10.5.10.116
|
||
db.port: "3306"
|
||
kind: ConfigMap
|
||
metadata:
|
||
creationTimestamp: "2019-02-14T08:22:34Z"
|
||
name: test-config1
|
||
namespace: default
|
||
resourceVersion: "7587"
|
||
selfLink: /api/v1/namespaces/default/configmaps/test-config1
|
||
uid: adfff64c-3031-11e9-abbe-000c290a5b8b
|
||
```
|
||
|
||
通过指定文件创建：
|
||
|
||
编辑配置文件app.properties内容如下
|
||
|
||
```shell
|
||
[root@master yaml]# cat app.properties
|
||
property.1 = value-1
|
||
property.2 = value-2
|
||
property.3 = value-3
|
||
property.4 = value-4
|
||
|
||
[mysqld]
|
||
!include /home/wing/mysql/etc/mysqld.cnf
|
||
port = 3306
|
||
socket = /home/wing/mysql/tmp/mysql.sock
|
||
pid-file = /wing/mysql/mysql/var/mysql.pid
|
||
basedir = /home/mysql/mysql
|
||
datadir = /wing/mysql/mysql/var
|
||
```
|
||
|
||
创建（可以有多个--from-file）
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl create configmap test-config2 --from-file=./app.properties
|
||
```
|
||
|
||
结果如下面data内容所示
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl get configmap test-config2 -o yaml
|
||
apiVersion: v1
|
||
data:
|
||
app.properties: |
|
||
property.1 = value-1
|
||
property.2 = value-2
|
||
property.3 = value-3
|
||
property.4 = value-4
|
||
|
||
[mysqld]
|
||
!include /home/wing/mysql/etc/mysqld.cnf
|
||
port = 3306
|
||
socket = /home/wing/mysql/tmp/mysql.sock
|
||
pid-file = /wing/mysql/mysql/var/mysql.pid
|
||
basedir = /home/mysql/mysql
|
||
datadir = /wing/mysql/mysql/var
|
||
kind: ConfigMap
|
||
metadata:
|
||
creationTimestamp: "2019-02-14T08:29:33Z"
|
||
name: test-config2
|
||
namespace: default
|
||
resourceVersion: "8176"
|
||
selfLink: /api/v1/namespaces/default/configmaps/test-config2
|
||
uid: a8237769-3032-11e9-abbe-000c290a5b8b
|
||
```
|
||
|
||
通过指定文件创建时，configmap会创建一个key/value对，key是文件名，value是文件内容。如不想configmap中的key为默认的文件名，可以在创建时指定key名字
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl create configmap game-config-3 --from-file=<my-key-name>=<path-to-file>
|
||
```
|
||
|
||
指定目录创建：
|
||
|
||
configs 目录下的config-1和config-2内容如下所示
|
||
|
||
```shell
|
||
[root@master yaml]# tail configs/config-1
|
||
aaa
|
||
bbb
|
||
c=d
|
||
[root@master yaml]# tail configs/config-2
|
||
eee
|
||
fff
|
||
h=k
|
||
```
|
||
|
||
创建
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl create configmap test-config3 --from-file=./configs
|
||
```
|
||
|
||
结果下面data内容所示
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl get configmap test-config3 -o yaml
|
||
apiVersion: v1
|
||
data:
|
||
config-1: |
|
||
aaa
|
||
bbb
|
||
c=d
|
||
config-2: |
|
||
eee
|
||
fff
|
||
h=k
|
||
kind: ConfigMap
|
||
metadata:
|
||
creationTimestamp: "2019-02-14T08:37:05Z"
|
||
name: test-config3
|
||
namespace: default
|
||
resourceVersion: "8808"
|
||
selfLink: /api/v1/namespaces/default/configmaps/test-config3
|
||
uid: b55ffbeb-3033-11e9-abbe-000c290a5b8b
|
||
```
|
||
|
||
指定目录创建时，configmap内容中的各个文件会创建一个key/value对，key是文件名，value是文件内容，忽略子目录
|
||
|
||
通过事先写好configmap的标准yaml文件创建：
|
||
|
||
yaml文件内容如下： 注意其中一个key的value有多行内容时的写法
|
||
|
||
```shell
|
||
[root@master yaml]# cat configmap.yaml
|
||
apiVersion: v1
|
||
kind: ConfigMap
|
||
metadata:
|
||
name: test-config4
|
||
namespace: default
|
||
data:
|
||
cache_host: memcached-gcxt
|
||
cache_port: "11211"
|
||
cache_prefix: gcxt
|
||
my.cnf: |
|
||
[mysqld]
|
||
log-bin = mysql-bin
|
||
haha = hehe
|
||
```
|
||
|
||
创建
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl apply -f configmap.yaml
|
||
configmap/test-config4 created
|
||
```
|
||
|
||
结果如下面data内容所示
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl get configmap test-config4 -o yaml
|
||
apiVersion: v1
|
||
data:
|
||
cache_host: memcached-gcxt
|
||
cache_port: "11211"
|
||
cache_prefix: gcxt
|
||
my.cnf: |
|
||
[mysqld]
|
||
log-bin = mysql-bin
|
||
haha = hehe
|
||
kind: ConfigMap
|
||
metadata:
|
||
annotations:
|
||
kubectl.kubernetes.io/last-applied-configuration: |
|
||
{"apiVersion":"v1","data":{"cache_host":"memcached-gcxt","cache_port":"11211","cache_prefix":"gcxt","my.cnf":"[mysqld]\nlog-bin = mysql-bin\nhaha = hehe\n"},"kind":"ConfigMap","metadata":{"annotations":{},"name":"test-config4","namespace":"default"}}
|
||
creationTimestamp: "2019-02-14T08:46:57Z"
|
||
name: test-config4
|
||
namespace: default
|
||
resourceVersion: "9639"
|
||
selfLink: /api/v1/namespaces/default/configmaps/test-config4
|
||
uid: 163fbe1e-3035-11e9-abbe-000c290a5b8b
|
||
```
|
||
|
||
查看configmap的详细信息
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl describe configmap
|
||
```
|
||
|
||
#### 3.使用ConfigMap
|
||
|
||
通过环境变量的方式，直接传递pod
|
||
|
||
通过在pod的命令行下运行的方式
|
||
|
||
使用volume的方式挂载入到pod内
|
||
|
||
示例ConfigMap文件：
|
||
|
||
```shell
|
||
apiVersion: v1
|
||
kind: ConfigMap
|
||
metadata:
|
||
name: special-config
|
||
namespace: default
|
||
data:
|
||
special.how: very
|
||
special.type: charm
|
||
```
|
||
|
||
通过环境变量使用：
|
||
|
||
使用valueFrom、configMapKeyRef、name、key指定要用的key
|
||
|
||
```shell
|
||
[root@master yaml]# cat testpod.yaml
|
||
apiVersion: v1
|
||
kind: Pod
|
||
metadata:
|
||
name: dapi-test-pod
|
||
spec:
|
||
containers:
|
||
- name: test-container
|
||
image: daocloud.io/library/nginx
|
||
env:
|
||
- name: SPECIAL_LEVEL_KEY //这里是容器里设置的新变量的名字
|
||
valueFrom:
|
||
configMapKeyRef:
|
||
name: special-config //这里是来源于哪个configMap
|
||
key: special.how //configMap里的key
|
||
- name: SPECIAL_TYPE_KEY
|
||
valueFrom:
|
||
configMapKeyRef:
|
||
name: special-config
|
||
key: special.type
|
||
restartPolicy: Never
|
||
```
|
||
|
||
测试
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl exec -it dapi-test-pod /bin/bash
|
||
root@dapi-test-pod:/# echo $SPECIAL_TYPE_KEY
|
||
charm
|
||
```
|
||
|
||
通过envFrom、configMapRef、name使得configmap中的所有key/value对都自动变成环境变量
|
||
|
||
```shell
|
||
apiVersion: v1
|
||
kind: Pod
|
||
metadata:
|
||
name: dapi-test-pod
|
||
spec:
|
||
containers:
|
||
- name: test-container
|
||
image: daocloud.io/library/nginx
|
||
envFrom:
|
||
- configMapRef:
|
||
name: special-config
|
||
restartPolicy: Never
|
||
```
|
||
|
||
这样容器里的变量名称直接使用configMap里的key名
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl exec -it dapi-test-pod /bin/bash
|
||
root@dapi-test-pod:/# env
|
||
HOSTNAME=dapi-test-pod
|
||
NJS_VERSION=1.15.8.0.2.7-1~stretch
|
||
NGINX_VERSION=1.15.8-1~stretch
|
||
KUBERNETES_PORT_443_TCP_PROTO=tcp
|
||
KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1
|
||
KUBERNETES_PORT=tcp://10.96.0.1:443
|
||
PWD=/
|
||
special.how=very
|
||
HOME=/root
|
||
KUBERNETES_SERVICE_PORT_HTTPS=443
|
||
KUBERNETES_PORT_443_TCP_PORT=443
|
||
KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443
|
||
TERM=xterm
|
||
SHLVL=1
|
||
KUBERNETES_SERVICE_PORT=443
|
||
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
|
||
special.type=charm
|
||
KUBERNETES_SERVICE_HOST=10.96.0.1
|
||
```
|
||
|
||
作为volume挂载使用：
|
||
|
||
```shell
|
||
apiVersion: apps/v1
|
||
kind: Deployment
|
||
metadata:
|
||
name: nginx-configmap
|
||
spec:
|
||
replicas: 1
|
||
selector:
|
||
matchLabels:
|
||
app: nginx
|
||
template:
|
||
metadata:
|
||
labels:
|
||
app: nginx
|
||
spec:
|
||
containers:
|
||
- name: nginx-configmap
|
||
image: daocloud.io/library/nginx:latest
|
||
ports:
|
||
- containerPort: 80
|
||
volumeMounts:
|
||
- name: config-volume3
|
||
mountPath: /tmp/config3
|
||
volumes:
|
||
- name: config-volume3
|
||
configMap:
|
||
name: test-config-3
|
||
```
|
||
|
||
进入容器中/tmp/config4查看
|
||
|
||
```shell
|
||
[root@master yaml]# kubectl exec -it nginx-configmap-7447bf77d6-svj2t /bin/bash
|
||
|
||
root@nginx-configmap-7447bf77d6-svj2t:/# ls /tmp/config4/
|
||
cache_host cache_port cache_prefix my.cnf
|
||
|
||
root@nginx-configmap-7447bf77d6-svj2t:/# cat /tmp/config4/cache_host
|
||
memcached-gcxt
|
||
|
||
可以看到，在config4文件夹下以每一个key为文件名value为值创建了多个文件。
|
||
```
|
||
|
||
假如不想以key名作为配置文件名可以引入items 字段，在其中逐个指定要用相对路径path替换的key：
|
||
|
||
```shell
|
||
volumes:
|
||
- name: config-volume4
|
||
configMap:
|
||
name: test-config4
|
||
items:
|
||
- key: my.cnf //原来的key名
|
||
path: mysql-key
|
||
- key: cache_host //原来的key名
|
||
path: cache-host
|
||
```
|
||
|
||
注意：
|
||
|
||
删除configmap后原pod不受影响；然后再删除pod后，重启的pod的events会报找不到cofigmap的volume
|
||
|
||
pod起来后再通过kubectl edit configmap …修改configmap，过一会pod内部的配置也会刷新
|
||
|
||
在容器内部修改挂进去的配置文件后，过一会内容会再次被刷新为原始configmap内容
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|