ConfigMap
A ConfigMap is a resource object for storing configuration information required by applications. It uses the key-value pair to save configuration data. It can be used to save a single attribute or configuration file.
A ConfigMap can be used to decouple configuration and make different configurations in different environments. Compared with the environment variables, the ConfigMap referenced in the pod can be updated in real time. After the ConfigMap data is updated, the ConfigMap referenced in the pod is updated synchronously.
Creating a ConfigMap
In the following example, a ConfigMap named configmap-test is created. The ConfigMap configuration data is defined in the data field.
apiVersion: v1 kind: ConfigMap metadata: name: configmap-test data: # Configuration data property_1: Hello property_2: World
Referencing a ConfigMap in Environment Variables
A ConfigMap is usually referenced in environment variables and volumes.
In the following example, the property_1 of configmap-test is used as the value of the environment variable EXAMPLE_PROPERTY_1. In this case, the value of EXAMPLE_PROPERTY_1 is the value of property_1 after the container is started, that is, Hello.
apiVersion: v1 kind: Pod metadata: name: nginx spec: containers: - image: nginx:latest name: container-0 resources: limits: cpu: 500m memory: 1024Mi requests: cpu: 500m memory: 1024Mi env: - name: EXAMPLE_PROPERTY_1 valueFrom: configMapKeyRef: # Reference the ConfigMap name: configmap-test key: property_1 imagePullSecrets: - name: imagepull-secret
Referencing a ConfigMap in a Volume
Referencing a ConfigMap in a volume is to fill its data in configuration files in the volume. Each piece of data is saved in a file. The key is the file name, and the key value is the file content.
In the following example, create a volume named vol-configmap, reference the ConfigMap named configmap-test in the volume, and mount the volume to the /tmp directory of the container. After the pod is created, there are two files property_1 and property_2 in the /tmp directory of the container, and the values are Hello and World.
apiVersion: v1 kind: Pod metadata: name: nginx spec: containers: - image: nginx:latest name: container-0 resources: limits: cpu: 500m memory: 1024Mi requests: cpu: 500m memory: 1024Mi volumeMounts: - name: vol-configmap # Mount the volume named vol-configmap mountPath: "/tmp1" imagePullSecrets: - name: imagepull-secret volumes: - name: vol-configmap configMap: # Reference the ConfigMap name: configmap-test
Feedback
Was this page helpful?
Provide feedbackThank you very much for your feedback. We will continue working to improve the documentation.See the reply and handling status in My Cloud VOC.
For any further questions, feel free to contact us through the chatbot.
Chatbot