ConfigMap

PPG007 ... 2022-4-11 About 2 min

# ConfigMap

ConfigMap 允许将配置文件与镜像文件分离。

# 使用 kubectl 创建 ConfigMap

执行下面的命令可以在指定名称空间创建一个 ConfigMap：

kubectl create configmap application-config --from-file=application.toml -n example

其中 application-config 是这个 ConfigMap 的名字，from-file 可以是单个文件也可以是目录，--from-env-file 参数可以从环境文件创建 ConfigMap，环境文件每一行必须是 k=v 的格式，如果使用了多个 --from-env-file 参数，只有最后一个环境文件会生效。

使用 --from-file 参数时，可以使用下面这种形式自定义键名取代默认使用文件名的行为：

kubectl create configmap application-config --from-file=key=application.toml -n example

--from-literal 参数可以通过直接在命令中指定字面量来创建 ConfigMap。

# 配置文件创建

使用下面的配置文件可以创建一个 ConfigMap：

apiVersion: v1
kind: ConfigMap
metadata:
  name: application-config
  namespace: example
data:
  application.toml: |
    [mysql]

    url = "mysql://localhost:3306"
    username = "root"
    password = "123456"

    [mongodb]

    url = "mongo://localhost:27017"
    username = "mongo"
    password = "654321"

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

# 使用 ConfigMap 定义 Pod 环境变量

# 使用单一 ConfigMap

创建下面的这个 Deployment 并将一个 ConfigMap 挂载进去：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: volume-demo
  namespace: example
spec:
  selector:
    matchLabels:
      app: volume-demo
  replicas: 2
  template:
    metadata:
      labels:
        app: volume-demo
    spec:
      imagePullSecrets:
        - name: myali-docker
      containers:
      - name: volume-demo
        image: registry.cn-qingdao.aliyuncs.com/ppg007/volume-demo:2.0
        imagePullPolicy: Always
        env:
          - name: DEMO_ENV
            valueFrom:
              configMapKeyRef:
                name: application-config
                key: application.toml
        ports:
        - containerPort: 8080

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29

# 使用多个 ConfigMap

下面的 Deployment 使用了两个 ConfigMap：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: volume-demo
  namespace: example
spec:
  selector:
    matchLabels:
      app: volume-demo
  replicas: 2
  template:
    metadata:
      labels:
        app: volume-demo
    spec:
      imagePullSecrets:
        - name: myali-docker
      containers:
      - name: volume-demo
        image: registry.cn-qingdao.aliyuncs.com/ppg007/volume-demo:2.0
        imagePullPolicy: Always
        env:
          - name: DEMO_ENV
            valueFrom:
              configMapKeyRef:
                name: application-config
                key: application.toml
          - name: USERNAME
            valueFrom:
              configMapKeyRef:
                name: cm2
                key: username
          - name: PASSWORD
            valueFrom:
              configMapKeyRef:
                name: cm2
                key: password
        volumeMounts:
          - name: application
            mountPath: /root/configuration
        ports:
        - containerPort: 8080
      volumes:
        - name: application
          nfs:
            server: master
            path: /nfs/data

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47

# 将 ConfigMap 中的所有键值对配置为容器环境变量

apiVersion: apps/v1
kind: Deployment
metadata:
  name: volume-demo
  namespace: example
spec:
  selector:
    matchLabels:
      app: volume-demo
  replicas: 2
  template:
    metadata:
      labels:
        app: volume-demo
    spec:
      imagePullSecrets:
        - name: myali-docker
      containers:
      - name: volume-demo
        image: registry.cn-qingdao.aliyuncs.com/ppg007/volume-demo:2.0
        imagePullPolicy: Always
        envFrom:
          - configMapRef:
              name: cm2
        ports:
        - containerPort: 8080

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

# 将 ConfigMap 中的数据添加到卷

apiVersion: apps/v1
kind: Deployment
metadata:
  name: volume-demo
  namespace: example
spec:
  selector:
    matchLabels:
      app: volume-demo
  replicas: 2
  template:
    metadata:
      labels:
        app: volume-demo
    spec:
      imagePullSecrets:
        - name: myali-docker
      containers:
      - name: volume-demo
        image: registry.cn-qingdao.aliyuncs.com/ppg007/volume-demo:2.0
        imagePullPolicy: Always
        envFrom:
          - configMapRef:
              name: cm2
        volumeMounts:
          - name: application
            mountPath: /root/configuration
          - name: config-volume
            mountPath: /etc/config
        ports:
        - containerPort: 8080
      volumes:
        - name: application
          nfs:
            server: master
            path: /nfs/data
        - name: config-volume
          configMap:
            name: cm2

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39

上面的配置文件会在 /etc/config 目录中创建 cm2 ConfigMap 中的每个键值对，键为文件名，文件内容为值。这种方式中，/etc/config 目录中原有内容会被清除。

存储 Job