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。
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
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
[root@kube configMap]# kubectl log test-pod log is DEPRECATED and will be removed in a future version. Use logs instead. KUBERNETES_PORT=tcp://10.96.0.1:443 KUBERNETES_SERVICE_PORT=443 HOSTNAME=test-pod MY_SVC_SERVICE_PORT=80 MY_SVC_PORT=tcp://10.96.31.10:80 SHLVL=1 HOME=/root MY_SVC_PORT_80_TCP_ADDR=10.96.31.10 SPECIAL_TYPE_KEY=charm MY_SVC_PORT_80_TCP_PORT=80 MY_SVC_PORT_80_TCP_PROTO=tcp KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin KUBERNETES_PORT_443_TCP_PORT=443 MY_SVC_PORT_80_TCP=tcp://10.96.31.10:80 KUBERNETES_PORT_443_TCP_PROTO=tcp SPECIAL_LEVEL_KEY=very log_level=INFO MY_SVC_SERVICE_PORT_HTTP=80 KUBERNETES_SERVICE_PORT_HTTPS=443 KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443 KUBERNETES_SERVICE_HOST=10.96.0.1 PWD=/ MY_SVC_SERVICE_HOST=10.96.31.10 [root@kube configMap]#
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
[root@kube configMap]# kubectl logs dapi-test-pod
very charm
[root@kube configMap]#
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
[root@kube configMap]# kubectl logs vol-test-pod
very
[root@kube configMap]#
[root@kube configMap]#
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