目录
配置容器化应用配置的方式
- 自定义命令行参数来实现;
command
args []
- 把配置文件直接打入进项;
- 环境变量实现, 容器从物理机中的环境变量来导入配置
- 所配置的应用支持从环境变量中来读取
- 用预处理脚本
entrypoint
处理,通过环境变量传递过来的配置
- 存储卷;通过挂在对应的已经存放了配置文件的存储卷上
configMap
将配置文件从镜像中解耦, 从而增强了应用的可以执行以及应用的复制性.
命令创建和测试configMap
命令行键值对创建
kubectl describe configmap nginx-www -o yaml
[root@master volume]# kubectl create configmap nginx-config --from-literal=nginx_port=80 --from-literal=server_name=myapp.sijiayong.com
configmap/nginx-config created
[root@master volume]# kubectl get configmap
NAME DATA AGE
nginx-config 2 7s
[root@master volume]# kubectl describe configmap nginx-config
Name: nginx-config
Namespace: default
Labels: <none>
Annotations: <none>
Data
====
nginx_port:
----
80
server_name:
----
myapp.sijiayong.com
Events: <none>
创建一个Pod 挂在测试
配置清单如下:
[root@master configmap]# cat pod-configmap.yaml
apiVersion: v1
kind: Pod
metadata:
name: pod-cm
namespace: default
labels:
app: myapp
tier: frontend
annotations:
jubaozhu.com/created-by: "cluster admin"
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
ports:
- name: http
containerPort: 80
env: # 这里使用env, 表示容器中会用环境变量导入
- name: NGINX_SERVER_PORT # 这里的name表示容器中的key值
valueFrom:
configMapKeyRef:
name: nginx-config # 这里name是指向configMap对应的名称
key: nginx_port # 表示容器中key 所对应的 value的值, 此处取值的地方是定义的configMap中的对应的value值
- name: NGINX_SERVER_NAME # 因为要导入两个值,所以要写两份, 写法和上面的导入环境变量的方式相同
valueFrom:
configMapKeyRef:
name: nginx-config
key: server_name
创建后测试
[root@master configmap]# kubectl apply -f pod-configmap.yaml
pod/pod-cm created
[root@master configmap]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod-cm 1/1 Running 0 8s 10.244.1.30 node03.kubernetes <none> <none>
创建Pod后,进入到对应的容器中查看环境变量
把端口变更为8080
[root@master configmap]# kubectl exec -it pod-cm -- /bin/sh
/ # env
MYAPP_SVC_PORT_80_TCP_ADDR=10.98.57.156
KUBERNETES_PORT=tcp://10.96.0.1:443
KUBERNETES_SERVICE_PORT=443
MYAPP_SVC_PORT_80_TCP_PORT=80
HOSTNAME=pod-cm
SHLVL=1
MYAPP_SVC_PORT_80_TCP_PROTO=tcp
HOME=/root
NGINX_SERVER_PORT=80
NGINX_SERVER_NAME=myapp.sijiayong.com
... ...
... ...
可以通过命令行edit编辑configMap
[root@master configmap]# kubectl edit configmap nginx-config
configmap/nginx-config edited
[root@master configmap]# kubectl describe configmap nginx-config
Name: nginx-config
Namespace: default
Labels: <none>
Annotations: <none>
Data
====
nginx_port:
----
8080
server_name:
----
myapp.sijiayong.com
Events: <none>
修改之后, 需要些许时间等待后,容器中的环境变量就会变更,需要再次进入容器后查看环境变量中的端口的值是否有变化
命令行文件类创建方式
首先需要手动编辑一个相应的配置文件
[root@master configmap]# cat www.conf
server {
server_name myapp.sijiayong.com;
listen 80;
root /data/web/html/;
}
然后使用命令创建如下:
[root@master configmap]# kubectl create configmap nginx-www --from-file=www.conf # 这里只有一个等号, 表示 key 就是文件名称, 而value 是文件内容
configmap/nginx-www created
[root@master configmap]# kubectl get configmap
NAME DATA AGE
nginx-config 2 2m41s
nginx-www 1 4s
[root@master configmap]# kubectl describe configmap nginx-www
Name: nginx-www
Namespace: default
Labels: <none>
Annotations: <none>
Data
====
www.conf:
----
server {
server_name myapp.sijiayong.com;
listen 80;
root /data/web/html/;
}
Events: <none>
[root@master configmap]# kubectl get configmap nginx-www -o yaml
apiVersion: v1
data:
www.conf: |
server {
server_name myapp.sijiayong.com;
listen 80;
root /data/web/html/;
}
kind: ConfigMap
metadata:
creationTimestamp: "2019-08-06T08:44:37Z"
name: nginx-www
namespace: default
resourceVersion: "3850257"
selfLink: /api/v1/namespaces/default/configmaps/nginx-www
uid: 81050135-532c-4f0e-8fcf-99727cc2c498
创建Pod测试
创建相应清单文件
[root@master configmap]# cat pod-configmap-2.yaml
apiVersion: v1
kind: Pod
metadata:
name: pod-cm-2
namespace: default
labels:
app: myapp
tier: frontend
annotations:
jubaozhu.com/created-by: "cluster admin"
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
ports:
- name: http
containerPort: 80
volumeMounts: # 可直接挂在configMap到Pod中
- name: nginxconf # 这里指定卷名称
mountPath: /etc/nginx/config.d/ # 这里指定挂在的路径
readOnly: true # 这里表示当挂载失败的时候,容器能否启动成功,True表示可以正常启动,否则一点挂载失败,Pod的状态是Error
volumes: # 定义一个卷, 实质上是一个configMap
- name: nginxconf # 卷名称
configMap:
name: nginx-config # 这里指定 configMap对应的名称
创建后测试
[root@master configmap]# kubectl apply -f pod-configmap-2.yaml
pod/pod-cm-2 created
[root@master configmap]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod-cm-2 1/1 Running 0 5s 10.244.2.29 node02.kubernetes <none> <none>
然后进入Pod中查看挂在是否正常
[root@master configmap]# kubectl exec -it pod-cm-2 -- /bin/sh
/ # cd /etc/nginx/config.d/
/etc/nginx/config.d # ls -l
total 0
lrwxrwxrwx 1 root root 17 Aug 6 09:12 nginx_port -> ..data/nginx_port
lrwxrwxrwx 1 root root 18 Aug 6 09:12 server_name -> ..data/server_name
/etc/nginx/config.d # cat server_name
myapp.sijiayong.com/etc/nginx/config.d # cat nginx_port # servername显示正常
8080/etc/nginx/config.d # exit # 端口显示正常
同样也支持在线修改, 需要些许时间后就容器中的对应的值就会产生变化
贴近实际进行测试
上面创建了一个nginx-www
的一个正常的nginx主机的一个配置文件, 下面挂在到Pod中尝试访问是否正常
[root@master configmap]# vim pod-configmap-3.yaml
apiVersion: v1
kind: Pod
metadata:
name: pod-cm-3
namespace: default
labels:
app: myapp
tier: frontend
annotations:
jubaozhu.com/created-by: "cluster admin"
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
ports:
- name: http
containerPort: 80
volumeMounts:
- name: nginxconf
mountPath: /etc/nginx/conf.d/ # 挂载点为实际的nginx配置文件目录
readOnly: true
volumes:
- name: nginxconf
configMap:
name: nginx-www
创建后测试
[root@master configmap]# kubectl apply -f pod-configmap-3.yaml
pod/pod-cm-3 created
[root@master configmap]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod-cm-3 1/1 Running 0 6s 10.244.3.33 node01.kubernetes <none> <none>
进入Pod中查看
[root@master configmap]# kubectl exec -it pod-cm-3 -- /bin/sh
/ # cd /etc/nginx/conf.d/
/etc/nginx/conf.d # ls
www.conf
/etc/nginx/conf.d # cat www.conf
server {
server_name myapp.sijiayong.com;
listen 8088;
root /data/web/html/;
}
因为配置的nginx虚拟主机对应的目录不存在,下面来手动创建目录和写入测试内容
[root@master configmap]# kubectl exec -it pod-cm-3 -- /bin/sh
/ # mkdir /data/web/html -p
/ # echo '<h1>Nginx Server configured by ConfigMap</h1>' > /data/web/html/index.html
集群外部测试访问:
<h1>Nginx Server configured by ConfigMap</h1>
[root@master configmap]# curl 10.244.3.33:80
需要注意的是, 如果在线修改了configMap后, 这里需要手动进入到Pod中, 重载一下nginx才可以, 否则不生效