kubernetes configmap

ConfigMaps允许您将配置工件与image内容分离，以保持容器化应用程序的便携性。 本页面提供了一系列使用示例，演示如何使用ConfigMaps中存储的数据创建ConfigMaps和配置Pod。

Create ConfigMaps from directories

[root@mhc config_dir]# ls
a.cnf  b.cnf

kubectl create configmap test-config --from-file=`pwd`

[root@mhc config_dir]# kubectl describe configmaps test-config
Name:         test-config
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
a.cnf:
----
haha
lala
balabala

b.cnf:
----
you are stupid!
heng heng

Events:  <none>
===================================

kubectl create configmap test-config2 --from-file=`pwd`/a.cnf

kubectl create configmap test-config3 --from-file=`pwd`/a.cnf --from-file=`pwd`/b.cnf

[root@mhc config_dir]# kubectl create configmap test-config4 --from-file=key1=`pwd`/a.cnf --from-file=key2=`pwd`/b.cnf
configmap "test-config4" created
[root@mhc config_dir]#
[root@mhc config_dir]#
[root@mhc config_dir]# kubectl describe configmap test-config4
Name:         test-config4
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
key1:
----
haha
lala
balabala

key2:
----
you are stupid!
heng heng

Events:  <none>
===================================

[root@mhc config_dir]# kubectl create configmap special-config --from-literal=special.how=very --from-literal=special.type=charm
configmap "special-config" created
[root@mhc config_dir]# kubectl get configmaps special-config -o yaml
apiVersion: v1
data:
  special.how: very
  special.type: charm
kind: ConfigMap
metadata:
  creationTimestamp: 2018-02-27T08:21:36Z
  name: special-config
  namespace: default
  resourceVersion: "61698"
  selfLink: /api/v1/namespaces/default/configmaps/special-config
  uid: 3a4a0483-1b97-11e8-a9e9-dcfe07d61067
========================================

kubectl create configmap consul-config --from-literal=datacenter=haha

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  labels:
    io.kompose.service: consul2
  name: consul
spec:
  replicas: 1
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        io.kompose.service: consul2
        name: consul2
    spec:
      containers:
      - args:
        - agent
        - -server
        - -client=0.0.0.0
        - -ui
        - -bootstrap
        - -bind=0.0.0.0
        image: consul:0.8.4
        name: consul
        ports:
        - containerPort: 8500
        - containerPort: 8300
        - containerPort: 8301
        - containerPort: 8302
        - containerPort: 8400
        resources:
          limits:
            memory: "134217728"
        env:
          - name: DATACENTER
            valueFrom:
              configMapKeyRef:
                name: consul-config
                key: datacenter
      restartPolicy: Always
status: {}

====================================================

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

=============================

Add ConfigMap data to a Volume

[root@mhc config_dir]# kubectl create configmap consul-config2 --from-file=`pwd`/my.cnf
configmap "consul-config2" created
[root@mhc config_dir]#
[root@mhc config_dir]# kubectl describe configmaps consul-config2
Name:         consul-config2
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
my.cnf:
----
[mysqld]
aa = bb
cc= ee

[client]
user = root
password = root.123

Events:  <none>

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  labels:
    io.kompose.service: consul3
  name: consul
spec:
  replicas: 2
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        io.kompose.service: consul3
        name: consul3
    spec:
      containers:
      - args:
        - agent
        - -server
        - -client=0.0.0.0
        - -ui
        - -bootstrap
        - -bind=0.0.0.0
        image: consul:0.8.4
        name: consul
        resources:
          limits:
            memory: "134217728"
        volumeMounts:
        - name: config-volume
          mountPath: /etc/myconfig
      volumes:
        - name: config-volume
          configMap:
            name: consul-config2
      restartPolicy: Always
status: {}

[root@mhc config_dir]# kubectl exec -ti consul-7b7bddfff6-9rmbw sh
/ # ls /etc/myconfig/
my.cnf
/ # cat /etc/myconfig/my.cnf
[mysqld]
aa = bb
cc= ee

[client]
user = root
password = root.123

===========================================================

volumes:
  - name: config-volume
    configMap:
      name: consul-config2
      items:
      - key: my.cnf
        path: mysql/my.cnf

/ # ls /etc/myconfig/mysql/
my.cnf
====================================

kind: PodPreset
apiVersion: settings.k8s.io/v1alpha1
metadata:
  name: consul-setting2
spec:
  selector:
    matchLabels:
      name: consul
  envFrom:
    - configMapRef:
        name: test-config