ConfigMap
ConfigMap用于保存配置数据的键值对,可以用来保存单个属性,也可以用来保存配置文件。ConfigMap跟secret很类似,但它可以更方便地处理不包含敏感信息的字符串。
ConfigMap创建
可以使用kubectl create configmap从文件、目录或者key-value字符串创建等创建ConfigMap。
# 从key-value字符串创建ConfigMap $ kubectl create configmap special-config --from-literal=special.how=very configmap "special-config" created $ kubectl get configmap special-config -o go-template='{{.data}}' map[special.how:very] # 从env文件创建 $ echo -e "a=b\nc=d" | tee config.env a=b c=d $ kubectl create configmap special-config --from-env-file=config.env configmap "special-config" created $ kubectl get configmap special-config -o go-template='{{.data}}' map[a:b c:d] # 从目录创建 $ mkdir config $ echo a>config/a $ echo b>config/b $ kubectl create configmap special-config --from-file=config/ configmap "special-config" created $ kubectl get configmap special-config -o go-template='{{.data}}' map[a:a b:b ]
ConfigMap使用
ConfigMap可以通过多种方式在Pod中使用,比如设置环境变量、设置容器命令行参数、在Volume中创建配置文件等。
注意
- ConfigMap必须在Pod引用它之前创建
- 使用envFrom时,将会自动忽略无效的键
- Pod只能使用同一个命名空间内的ConfigMap
用作环境变量
首先创建ConfigMap:
$ kubectl create configmap special-config --from-literal=special.how=very --from-literal=special.type=charm $ kubectl create configmap env-config --from-literal=log_level=INFO
然后以环境变量方式引用
apiVersion: v1 kind: Pod metadata: name: test-pod spec: containers: - name: test-container image: gcr.io/google_containers/busybox command: [ "/bin/sh", "-c", "env" ] 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 envFrom: - configMapRef: name: env-config restartPolicy: Never
当pod运行结束后,它的输出会包括
SPECIAL_LEVEL_KEY=very SPECIAL_TYPE_KEY=charm log_level=INFO
用作命令行参数
将ConfigMap用作命令行参数时,需要先把ConfigMap的数据保存在环境变量中,然后通过$(VAR_NAME)的方式引用环境变量.
apiVersion: v1 kind: Pod metadata: name: dapi-test-pod spec: containers: - name: test-container image: gcr.io/google_containers/busybox 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
当Pod结束后会输出
very charm
使用volume将ConfigMap作为文件或目录直接挂载
将创建的ConfigMap直接挂载至Pod的/etc/config目录下,其中每一个key-value键值对都会生成一个文件,key为文件名,value为内容
apiVersion: v1 kind: Pod metadata: name: vol-test-pod spec: containers: - name: test-container image: gcr.io/google_containers/busybox command: [ "/bin/sh", "-c", "cat /etc/config/special.how" ] volumeMounts: - name: config-volume mountPath: /etc/config volumes: - name: config-volume configMap: name: special-config restartPolicy: Never
当Pod结束后会输出
very
将创建的ConfigMap中special.how这个key挂载到/etc/config目录下的一个相对路径/keys/special.level。如果存在同名文件,直接覆盖。其他的key不挂载
apiVersion: v1 kind: Pod metadata: name: dapi-test-pod spec: containers: - name: test-container image: gcr.io/google_containers/busybox command: [ "/bin/sh","-c","cat /etc/config/keys/special.level" ] volumeMounts: - name: config-volume mountPath: /etc/config volumes: - name: config-volume configMap: name: special-config items: - key: special.how path: keys/special.level restartPolicy: Never
当Pod结束后会输出
very
参考:https://feisky.gitbooks.io/kubernetes/concepts/configmap.html

先来个沙发再提问
创建configmap时怎么指定namespace