kubernetes资源对象之ConfigMap
2020-03-27 本文已影响0人
一舍
ConfigMap用来保存应用的配置信息。
ConfigMap的创建
ConfigMap的创建支持三种模式：
- 从目录创建
- 从文件创建
- 从字符创建
从目录创建ConfigMap
从同一目录中的多个文件创建 ConfigMap
ls configure-pod-container/configmap/
game.properties ui.properties
kubectl create c game-config-1 --from-file=configure-pod-container/configmap/
kubectl get configmaps game-config -o yaml
apiVersion: v1
kind: ConfigMap
metadata:
creationTimestamp: 2016-02-18T18:52:05Z
name: game-config
namespace: default
resourceVersion: "516"
selfLink: /api/v1/namespaces/default/configmaps/game-config
uid: b4952dc3-d670-11e5-8cd0-68f728db1985
data:
game.properties: |
enemies=aliens
lives=3
enemies.cheat=true
enemies.cheat.level=noGoodRotten
secret.code.passphrase=UUDDLRLRBABAS
secret.code.allowed=true
secret.code.lives=30
ui.properties: |
color.good=purple
color.bad=yellow
allow.textmode=true
how.nice.to.look=fairlyNice
从文件创建ConfigMap
从多个文件创建ConfigMap
ls configure-pod-container/configmap/
game.properties ui.properties
kubectl create configmap game-config-2 --from-file=configure-pod-container/configmap/game.properties --from-file=configure-pod-container/configmap/ui.properties
从环境变量文件创建ConfigMap
ls configure-pod-container/configmap/
game-env-file.properties
kubectl create configmap game-config-env-file --from-env-file=configure-pod-container/configmap/game-env-file.properties
kubectl get configmap game-config-env-file -o yaml
apiVersion: v1
kind: ConfigMap
metadata:
creationTimestamp: 2017-12-27T18:36:28Z
name: game-config-env-file
namespace: default
resourceVersion: "809965"
selfLink: /api/v1/namespaces/default/configmaps/game-config-env-file
uid: d9d1ca5b-eb34-11e7-887b-42010a8002b8
data:
allowed: '"true"'
enemies: aliens
lives: "3"
当使用多个
--from-env-file来从多个数据源创建 ConfigMap 时，仅仅最后一个 env 文件有效
从文件创建ConfigMap支持自定义键
在使用--from-file参数定义ConfigMap时，默认情况下键值是文件名，Kubernetes支持自定义除文件名称之外的键
kubectl create configmap game-config-3 --from-file=game-special-key=configure-pod-container/configmap/game.properties
kubectl get configmaps game-config-3 -o yaml
apiVersion: v1
kind: ConfigMap
metadata:
creationTimestamp: 2016-02-18T18:54:22Z
name: game-config-3
namespace: default
resourceVersion: "530"
selfLink: /api/v1/namespaces/default/configmaps/game-config-3
uid: 05f8da22-d671-11e5-8cd0-68f728db1985
data:
game-special-key: |
enemies=aliens
lives=3
enemies.cheat=true
enemies.cheat.level=noGoodRotten
secret.code.passphrase=UUDDLRLRBABAS
secret.code.allowed=true
secret.code.lives=30
从Json/Yaml文件创建
Kubernetes除了支持通过命令行创建ConfigMap外，还支持从json/yaml文件创建ConfigMap
apiVersion: v1
kind: ConfigMap
metadata:
name: special-config
namespace: default
data:
special.how: very
special.type: charm
kubectl create -f config.yaml
configmap "special-config" created
kubectl get configmaps special-config -o yaml
apiVersion: v1
kind: ConfigMap
metadata:
creationTimestamp: 2016-02-18T19:14:38Z
name: special-config
namespace: default
resourceVersion: "651"
selfLink: /api/v1/namespaces/default/configmaps/special-config
uid: dadce046-d673-11e5-8cd0-68f728db1985
data:
special.how: very
special.type: charm
从字符创建ConfigMap
kubectl create configmap special-config --from-literal=special.how=very --from-literal=special.type=charm
kubectl get configmaps special-config -o yaml
apiVersion: v1
kind: ConfigMap
metadata:
creationTimestamp: 2016-02-18T19:14:38Z
name: special-config
namespace: default
resourceVersion: "651"
selfLink: /api/v1/namespaces/default/configmaps/special-config
uid: dadce046-d673-11e5-8cd0-68f728db1985
data:
special.how: very
special.type: charm
ConfigMap的使用
ConfigMap中保存着应用的配置信息，在使用这些信息时，支持两种使用模式：
- 作为环境变量
- 作为挂载数据
定义容器的环境变量
定义容器的环境变量，支持两种模式：
- 将ConfigMap中定义的键的值分配给PodSpec中定义的环境变量
apiVersion: v1
kind: Pod
metadata:
name: dapi-test-pod
spec:
containers:
- name: test-container
image: k8s.gcr.io/busybox
command: [ "/bin/sh", "-c", "env" ]
env:
- name: SPECIAL_LEVEL_KEY
valueFrom:
configMapKeyRef:
name: special-config
key: special.how
- name: LOG_LEVEL
valueFrom:
configMapKeyRef:
name: env-config
key: log_level
restartPolicy: Never
- 将ConfigMap中定义的所有键值对配置为Pod的环境变量
apiVersion: v1
kind: Pod
metadata:
name: dapi-test-pod
spec:
containers:
- name: test-container
image: k8s.gcr.io/busybox
command: [ "/bin/sh", "-c", "env" ]
envFrom:
- configMapRef:
name: special-config
restartPolicy: Never
ConfigMap 中的键成为 Pod 中的环境变量名称
挂载ConfigMap 中的数据
在 Pod 的PodSpec的 volumes 部分下添加 ConfigMap 名称，这会将 ConfigMap 数据添加到指定为 volumeMounts.mountPath 的目录，键值为目录下文件的文件名。
将ConfigMap挂载到指定目录下，支持三种模式：
- 键值文件直接挂载到指定目录下
- 键值文件挂载到指定目录的子目录下
将键值文件直接挂载到指定目录下
apiVersion: v1
kind: Pod
metadata:
name: dapi-test-pod
spec:
containers:
- name: test-container
image: k8s.gcr.io/busybox
command: [ "/bin/sh", "-c", "ls /etc/config/" ]
volumeMounts:
- name: config-volume
mountPath: /etc/config
volumes:
- name: config-volume
configMap:
name: special-config
restartPolicy: Never
ls /etc/config/
SPECIAL_LEVEL SPECIAL_TYPE
将键值文件挂载到指定目录的子目录下
apiVersion: v1
kind: Pod
metadata:
name: dapi-test-pod
spec:
containers:
- name: test-container
image: k8s.gcr.io/busybox
command: [ "/bin/sh", "-c", "ls /etc/config/" ]
volumeMounts:
- name: config-volume
mountPath: /etc/config
volumes:
- name: config-volume
configMap:
name: special-config
items:
- key: SPECIAL_LEVEL
path: keys
restartPolicy: Never
ls /etc/config/
SPECIAL_LEVEL
一般情况下 ConfigMap 挂载文件时，会先覆盖掉挂载目录，然后再将 ConfigMap 中的内容作为文件挂载进行。如果想不对原来的文件夹下的文件造成覆盖，只是将 configmap 中的每个 键值，按照文件的方式挂载到目录下，可以使用 subpath 参数
apiVersion: v1
kind: Pod
metadata:
name: dapi-test-pod
spec:
containers:
- name: test-container
image: nginx
command: ["/bin/sh","-c","sleep 36000"]
volumeMounts:
- name: config-volume
mountPath: /etc/nginx/special.how
subPath: special.how
volumes:
- name: config-volume
configMap:
name: special-config
items:
- key: special.how
path: special.how
restartPolicy: Never
