configMap
configMap描述信息
ConfigMap功能在Kubernetes1.2版本中引入,许多应用程序会从配置文件、命令行参数或环境变量中读取配置信息。 ConfigMap API给我们提供了向容器中注入配置信息的机制, ConfigMap可以被用来保存单个属性,也可以用来保存整个配置文件或者JSON二进制大对象
ConfigMap的创建
1、使用目录创建
$1s docs/user-guide/configmap/kubect1/
game.properties
ui.properties
$ cat docs/user-guide/configmap/kubectl/game.properties
enemies=aliens
livess=3
enemies.cheat=true
enemies.cheat.level=noGoodRotten
secret.code.passphrase=UUDDLRLRBABAS
secret.code.allowed=true
secret.code.lives=30
cat docs/user-guide/configmap/kubectl/ui.properties
color.good=purple
color.bad=yellow
allow.textmode=true
how.nice.to.look=fairlyNice
$ kubectl create configmap game-config --from-file=docs/user-guide/configmap/kubect1
kubectl get cm
kubectl get cm game-config
kubectl get cm game-config -o yaml --查看配置
kubectl describe cm game-config --查看配置
-from-file指定在目录下的所有文件都会被用在ConfigMap里面创建一个键值对,键的名字就是文件名,值就是文件的内容
注意：键值对后边不要有空格
Ⅱ、使用文件创建
只要指定为一个文件就可以从单个文件中创建ConfigMap
kubectl create configmap game-config-2 --from-file=/root/configmap/dir/gameconfig.properties
kubectl get cm game-config-2 -o yaml
-from-file这个参数可以使用多次,你可以使用两次分别指定上个实例中的那两个配置文件,效果就跟指定整个目录是一样的
Ⅲ、使用字面值创建
使用文字值创建,利用-from-literal参数传递配置信息,该参数可以使用多次,格式如下
kubectl create configmap special-config --from-literal=special.how=very --from-literal=special.type=charm
$ kubectl get configmaps special-config -o yaml
Pod中使用ConfigMap
Ⅰ、使用ConfigMap来替代环境变量
apiVersion: v1
kind: ConfigMap
metadata:
name: special-config
namespace: default
data:
special.how: very
special.type: charm
apiVersion: v1
kind: ConfigMap
metadata:
name: env-config
namespace: default
data:
log_level:INFO
apiVersion: v1
kind: Pod
metadata:
name: dapi-test-pod
spec:
containers:
- name: test-container
image: hub.atguigu.com/library/myapp:v1
command: ["/bin/sh", "-c", "env"]
env:
- name: SPECIAL_TYPE_KEY
valueFrom:
configMapKeyRef:
name: special-config
key: special.how
- name: SPECIAL_TYPE_KEY
valueFrom:
configMapKeyRef:
name: special-config
key: special.type
envFrom:
- configMapRef:
name: env-config
restartPolicy: Never
Ⅱ、用ConfigMap设置命令行参数
apiVersion: v1
kind: Pod
metadata:
name: dapi-test-pod
spec:
containers:
- name: test-container
image: hub.atguigu.com/library/myapp:v1
command: [ "/bin/sh", "-c", "echo $(SPECIAL_LEVEL_KEY) $(SPECIAL_TYPE_KEY)" ]
env:
- name: SPECIAL_LEVEL_KEY
valueFrom:
configMapKeyRef:
name: special-config
key: special.how
- name: SPECIAL_TYPE_KEY
valueFrom:
configMapKeyRef:
name: special-config
key: special.type
restartPolicy: Never
Ⅲ、通过数据卷插件使用ConfigMap
在数据卷里面使用这个ConfigMap,有不同的选项。最基本的就是将文件填入数据卷,在这个文件中,键就是文件名,键值就是文件内容
apiversion: v1
kind: Pod
metadata:
name: dapi-test-pod3
spec:
containers:
- name: test-container
image: hub.atguigu.com/library/myapp:v1
command: [ "/bin/sh", "-c", "sleep 600s" ]
volumeMounts:
- name: config-volume
mountPath: /etc/config
volumes:
- name: config-volume
configMap:
name: special-config
restartPolicy: Never
ConfigMap的热更新
apiVersion: v1
kind: ConfigMap
metadata:
name: log-config
namespace: default
data:
log_level:INFO
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: my-nginx
spec:
replicas: 1
template:
metadata:
labels:
run: my-nginx
spec:
containers:
- name: my-nginx
image: hub.atguigu.com/library/myapp:v1
ports:
- containerPort: 80
volumeMounts:
- name: config-volume
mountPath: /etc/config
volumes:
- name: config-volume
configMap:
name: log-config
[root@k8s-master01 ~]# kubectl exec my-nginx-7b55868ff4-wqh2q -it -- cat /etc/config/log_level
INFO
修改ConfigMap
$ kubectl edit configmap log-config
修改10g-level的值为DEBUG等待大概10秒钟时间,再次查看环境变量的值
$ kubect1 exec 'kubectl get pods -1 run=my-nginx -osname|cut -d "/"-f2 cat /tmp/1oglevel DEBUG
更新ConfigMap目前并不会触发相关Pod的滚动更新,可以通过修改pod annotations的方式强制触发滚动更新
$ kubectl patch deployment my-nginx--patch '{"spec": {"template": {"metadata": {"annotations": {"version/config": "20198411"}}}}}'
这个例子里我们在. spec.template.metadata. annotations中添加version/config ,每次通过修改 version/config来触发滚动更新
更新ConfigMap后:
-
使用该ConfigMap挂载的Env不会同步更新
-