Creating a ConfigMap

Scenario

A ConfigMap is a Kubernetes resource used to store non-sensitive configuration data. Its content is defined by users. After a ConfigMap is created, containerized workloads can use it through volume mounts or environment variable injection.

ConfigMaps decouple configuration files from container images, improving workload portability and preventing unnecessary image rebuilds caused by configuration changes.

The core benefits of ConfigMaps include:

Easy injection of configuration files into containers: Configuration files can be mounted directly to a specified path in a container, allowing configuration updates without modifying the image.
Unified management across multiple environments and services: Separate ConfigMaps can be created for different environments (such as development, testing, and production) or different service lines. This enables configuration isolation and efficient management.
Agile workload deployment and version control: The same workload can be deployed in different environments using different ConfigMaps. ConfigMaps support versioning, enabling efficient workload updates, iterations, and quick rollbacks.

Notes and Constraints

The size of a ConfigMap resource file cannot exceed 1 MiB.
ConfigMaps cannot be used in static pods.

Procedure

You can use either of the following ways.

Log in to the CCE console and click the cluster name to access the cluster console.
Choose ConfigMaps and Secrets in the navigation pane and click Create ConfigMap in the upper right corner.

Configure parameters.

**Table 1** Parameters for creating a ConfigMap
Parameter	Description
Name	Name of the ConfigMap you create, which must be unique in a namespace.
Namespace	Namespace to which the ConfigMap belongs. If you do not specify this parameter, the value default is used by default.
Description	Description of the ConfigMap.
Data	Data of the ConfigMap. Click Add and enter key-value pairs. Key: Enter 1 to 63 characters. Only digits, letters, periods (.), hyphens (-), and underscores (_) are allowed. The key cannot start with two periods (..). Value: The value can be in string, JSON, or YAML format.
Tag Management (Optional)	Labels of the ConfigMap. Click Add Label and enter key-value pairs. The key and value must contain 1 to 63 characters that start and end with a letter or digit. Only letters, digits, hyphens (-), underscores (_), and periods (.) are allowed.

Click OK.

The new ConfigMap is displayed in the ConfigMap list.

Use kubectl to access the cluster. For details, see Accessing a Cluster Using kubectl.

Create a file named cce-configmap.yaml and edit it.

vi cce-configmap.yaml

File content:

apiVersion: v1
kind: ConfigMap
metadata:
  name: cce-configmap
data:
  SPECIAL_LEVEL: Hello
  SPECIAL_TYPE: CCE

**Table 2** Key parameters
Parameter	Description
apiVersion	The value is fixed at v1.
kind	The value is fixed at ConfigMap.
metadata.name	ConfigMap name, which can be customized.
data	ConfigMap data. The value must be key-value pairs.

Run the following commands to create the ConfigMap:

kubectl create -f cce-configmap.yaml

Run the following commands to view the created ConfigMap:

kubectl get cm

Command output:

NAME               DATA            AGE
cce-configmap      3               7m

Related Operations

After creating a ConfigMap, you can update or delete it as described in Table 3.

**Table 3** Related operations
Operation	Description
Editing a ConfigMap's YAML file	Click Edit YAML in the row where the target ConfigMap resides to edit its YAML file.
Updating a ConfigMap	Select the name of the ConfigMap to be updated and click Update. Modify the information by referring to Table 1. NOTE: If you enable Version Management during the ConfigMap update, CCE automatically generates a historical version for the ConfigMap before modification for data management and rollback. Click OK.
Deleting a ConfigMap	Select the target ConfigMap and choose More > Delete. Delete the ConfigMap as instructed.
Rolling back a ConfigMap	Select the target ConfigMap and choose More > Rollback to roll back it to the specified historical version as instructed. This function is available only when the ConfigMap has a historical version.