二、ConfigMap

1、使用目录创建
#创建两个配置文件

[root@k8s-master01-etcd01 dir]# ls
game.properties  test.conf
[root@k8s-master01-etcd01 dir]# cat game.properties 
name=xiangwei
age=22
weapon=sword
[root@k8s-master01-etcd01 dir]# cat test.conf 
course=python
log-config=INFO

#创建configmap
[root@k8s-master01-etcd01 dir]# kubectl create configmap base-config --from-file=../dir/
configmap/base-config created

#查看
[root@k8s-master01-etcd01 dir]# kubectl get cm
NAME          DATA   AGE
base-config   2      27s
[root@k8s-master01-etcd01 dir]# kubectl describe cm base-config
Name:         base-config
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
game.properties:
----
name=xiangwei
age=22
weapon=sword

test.conf:
----
course=python
log-config=INFO

Events:  <none>

--from-file这个参数可以使用多次，可以直接指定配置文件名称，效果跟指定整个目录一样

kubectl create configmap game-config --from-file=../dir/game.properties
kubectl create configmap test-config --from-file=../dir/test.conf

2、使用yaml创建
创建单个数值

[root@k8s-master01-etcd01 yaml]# cat config.yaml 
apiVersion: v1
kind: ConfigMap
metadata:
  name: special-config
  namespace: default
data:
  special.how: very
  special.type: charm

[root@k8s-master01-etcd01 yaml]# cat config1.yaml 
apiVersion: v1
kind: ConfigMap
metadata:
  name: log-config
  namespace: default
data:
  log_level: INFO

[root@k8s-master01-etcd01 yaml]# kubectl apply -f config.yaml 
configmap/special-config created
[root@k8s-master01-etcd01 yaml]# kubectl apply -f config1.yaml 
configmap/log-config created
[root@k8s-master01-etcd01 yaml]# kubectl get cm
NAME             DATA   AGE
base-config      2      17m
log-config       1      62s
special-config   2      10m

#查看
[root@k8s-master01-etcd01 yaml]# kubectl describe cm special-config 
Name:         special-config
Namespace:    default
Labels:       <none>
Annotations:  kubectl.kubernetes.io/last-applied-configuration:
                {"apiVersion":"v1","data":{"special.how":"very","special.type":"charm"},"kind":"ConfigMap","metadata":{"annotations":{},"name":"special-co...

Data
====
special.how:
----
very
special.type:
----
charm
Events:  <none>
[root@k8s-master01-etcd01 yaml]# kubectl describe cm log-config 
Name:         log-config
Namespace:    default
Labels:       <none>
Annotations:  kubectl.kubernetes.io/last-applied-configuration:
                {"apiVersion":"v1","data":{"log_level":"INFO"},"kind":"ConfigMap","metadata":{"annotations":{},"name":"log-config","namespace":"default"}}

Data
====
log_level:
----
INFO
Events:  <none>

在pod中使用configmap来替代环境变量

[root@k8s-master01-etcd01 yaml]# cat test.pod.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: test-pod
spec:
  containers:
  - name: test-busybox
    image: busybox:1.28.4
    command: ["/bin/sh","-c","env"]
    env:    #自定义环境变量名称的方式
      - name: SPECIAL_LEVEL_KEY
        valueFrom:
          configMapKeyRef:
            name: special-config
            key: special.how
      - name: SPECIAL_TYPE_KEY
        valueFrom:
          configMapKeyRef:
            name: special-config
            key: special.type
    envFrom:   #由于base-config是文件的方式创建，可以看到环境变量中没有里面的数据
      - configMapRef:
          name: base-config 
    envFrom:   #环境变量名称使用configmap中定义的key方式
      - configMapRef:
          name: log-config
  restartPolicy: Never

[root@k8s-master01-etcd01 yaml]# kubectl apply -f test.pod.yaml 
pod/test-pod created

[root@k8s-master01-etcd01 yaml]# kubectl logs test-pod 
KUBERNETES_PORT=tcp://10.0.0.1:443
KUBERNETES_SERVICE_PORT=443
HOSTNAME=test-pod
SHLVL=1
HOME=/root
SPECIAL_TYPE_KEY=charm                              #special-config配置
NGINX_SERVICE_PORT_8001_TCP_ADDR=10.0.0.64
NGINX_SERVICE_PORT_8001_TCP_PORT=8001
NGINX_SERVICE_PORT_8001_TCP_PROTO=tcp
KUBERNETES_PORT_443_TCP_ADDR=10.0.0.1
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
NGINX_SERVICE_SERVICE_HOST=10.0.0.64
KUBERNETES_PORT_443_TCP_PORT=443
KUBERNETES_PORT_443_TCP_PROTO=tcp
NGINX_SERVICE_PORT_8001_TCP=tcp://10.0.0.64:8001
SPECIAL_LEVEL_KEY=very                             #special-config配置
NGINX_SERVICE_SERVICE_PORT=8001
NGINX_SERVICE_PORT=tcp://10.0.0.64:8001
log_level=INFO                                     #log-config配置
KUBERNETES_PORT_443_TCP=tcp://10.0.0.1:443
KUBERNETES_SERVICE_PORT_HTTPS=443
KUBERNETES_SERVICE_HOST=10.0.0.1
PWD=/

3、创建配置文件，以数据卷的方式挂载

挂载配置文件，挂载前面通过文件定义的configmap

[root@k8s-master01-etcd01 yaml]# cat test.pod1.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: test1-pod
spec:
  containers:
  - name: test1-busybox
    image: busybox:1.28.4
    command: ["/bin/sh","-c","sleep 600s"]
    volumeMounts:
    - name: settings
      mountPath: /opt/settings.conf
      subPath: game.properties  #指定配置文件，如果没有该配置，挂载点为一个目录 
  volumes:
    - name: settings
      configMap:
        name: base-config
  restartPolicy: Never

[root@k8s-master01-etcd01 yaml]# kubectl apply -f test.pod1.yaml 
pod/test1-pod created

[root@k8s-master01-etcd01 yaml]# kubectl exec -it test1-pod -- cat /opt/settings.conf/test.conf
course=python
log-config=INFO
[root@k8s-master01-etcd01 yaml]# kubectl exec -it test1-pod -- cat /opt/settings.conf/game.properties
name=xiangwei
age=22
weapon=sword

指定配置文件

[root@k8s-master01-etcd01 yaml]# kubectl exec -it test1-pod  -- cat /opt/settings.conf
name=xiangwei
age=22
weapon=sword

使用yaml创建配置文件

[root@k8s-master01-etcd01 yaml]# cat config2.yaml 
apiVersion: v1
kind: ConfigMap
metadata:
  name: nginx-config
  namespace: default
data:
  nginx.conf: |
    { 
      "ConnectionStrings": {"Redis": "redis-server","Reservation": "Server=localhost;uid=liweihan;pwd=**;database=Reservation", "ElasticSearch": "elasticsearch" },
      "MpWechat":{ "AppId": "wx4a41d3773ae55543", "AppSecret": "**********", "Token": "AmazingDotNet", "AESKey": "------------" },
      "AppSettings": { "WechatSubscribeReply": "", "SentryClientKey": "https://**" },
      "Tencent": { "Captcha": { "AppId": "2062135016", "AppSecret": "****" } },
      "GoogleRecaptcha": { "SiteKey": "6Lc-**", "Secret": "6Lc-**" },
      "Logging": { "LogLevel": { "Default": "Warning", "ActivityReservation": "Debug", "RequestLog": "Debug" } } 
    }

注意：|符号下面的字符也要符合yaml格式，开头空两格

[root@k8s-master01-etcd01 yaml]# cat test.pod2.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: test-pod2
spec:
  containers:
  - name: test2-busybox
    image: busybox:1.28.4
    command: ["/bin/sh","-c","sleep 600s"]
    volumeMounts:
    - name: settings
      mountPath: /opt/nginx.conf
      subPath: nginx.conf
  volumes:
    - name: settings
      configMap:
        name: nginx-config 
  restartPolicy: Never

[root@k8s-master01-etcd01 yaml]# kubectl apply -f config2.yaml 
configmap/nginx-config created
[root@k8s-master01-etcd01 yaml]# kubectl apply -f test.pod2.yaml 
pod/test-pod2 created

[root@k8s-master01-etcd01 yaml]#  kubectl exec -it test-pod2 -- cat /opt/nginx.conf
{ 
  "ConnectionStrings": {"Redis": "redis-server","Reservation": "Server=localhost;uid=liweihan;pwd=**;database=Reservation", "ElasticSearch": "elasticsearch" },
  "MpWechat":{ "AppId": "wx4a41d3773ae55543", "AppSecret": "**********", "Token": "AmazingDotNet", "AESKey": "------------" },
  "AppSettings": { "WechatSubscribeReply": "", "SentryClientKey": "https://**" },
  "Tencent": { "Captcha": { "AppId": "2062135016", "AppSecret": "****" } },
  "GoogleRecaptcha": { "SiteKey": "6Lc-**", "Secret": "6Lc-**" },
  "Logging": { "LogLevel": { "Default": "Warning", "ActivityReservation": "Debug", "RequestLog": "Debug" } } 
}

4、更新configMap
修改configMap中的值后，env环境变量中的值不会动态更新。
以挂载配置文件方式的，修改configMap中的值后，大约10秒后，容器中的值也会更新。

如果是deployment，可以通过更新注释的方式来触发更新。修改configmap的值，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

[root@k8s-master01-etcd01 yaml]# kubectl patch deployments my-busybox --patch '{"spec": {"template": {"metadata": {"annotations": {"version":"20191119"}}}}}'
deployment.apps/my-busybox patched