Overview
The ConfigMap class represents a Kubernetes ConfigMap, which holds configuration data for pods to consume. ConfigMaps allow you to decouple configuration artifacts from image content to keep containerized applications portable.
Class Definition
from ocp_resources.config_map import ConfigMap
v1
Constructor
ConfigMap accepts all parameters from NamespacedResource, plus:
Binary data to store. Each key must consist of alphanumeric characters, ’-’, ’_’ or ’.’. BinaryData can contain byte sequences that are not in the UTF-8 range. Keys must not overlap with the data field.
Configuration data to store. Each key must consist of alphanumeric characters, ’-’, ’_’ or ’.’. Values with non-UTF-8 byte sequences must use the binary_data field. Keys must not overlap with the binary_data field.
If set to true, ensures that data stored in the ConfigMap cannot be updated (only object metadata can be modified). If not set, the field can be modified at any time. Defaults to nil.
Properties
keys_to_hash
@property
def keys_to_hash(self) -> list[str]
["data", "binaryData"]
Inherited Methods
ConfigMap inherits all methods from NamespacedResource and Resource.
Examples
Creating a Simple ConfigMap
from ocp_resources.config_map import ConfigMap
from ocp_resources.resource import get_client
client = get_client()
config_map = ConfigMap(
client=client,
name="app-config",
namespace="default",
data={
"database_url": "postgres://localhost:5432/mydb",
"log_level": "info",
"max_connections": "100"
}
)
config_map.create()
print(f"ConfigMap {config_map.name} created")
Creating a ConfigMap with File-like Data
from ocp_resources.config_map import ConfigMap
from ocp_resources.resource import get_client
client = get_client()
config_map = ConfigMap(
client=client,
name="nginx-config",
namespace="default",
data={
"nginx.conf": """
server {
listen 80;
server_name example.com;
location / {
proxy_pass http://backend:8080;
}
}
""",
"mime.types": "text/html html htm shtml;\ntext/css css;"
}
)
config_map.create()
print("Nginx ConfigMap created")
Creating an Immutable ConfigMap
from ocp_resources.config_map import ConfigMap
from ocp_resources.resource import get_client
client = get_client()
config_map = ConfigMap(
client=client,
name="immutable-config",
namespace="default",
immutable=True,
data={
"api_key": "fixed-api-key",
"version": "1.0.0"
}
)
config_map.create()
print("Immutable ConfigMap created (cannot be updated)")
Creating a ConfigMap with Binary Data
import base64
from ocp_resources.config_map import ConfigMap
from ocp_resources.resource import get_client
client = get_client()
# Read binary file and encode
with open("/path/to/binary/file", "rb") as f:
binary_content = base64.b64encode(f.read()).decode("utf-8")
config_map = ConfigMap(
client=client,
name="binary-config",
namespace="default",
binary_data={
"app.bin": binary_content
}
)
config_map.create()
print("ConfigMap with binary data created")
Creating a ConfigMap from Multiple Sources
from ocp_resources.config_map import ConfigMap
from ocp_resources.resource import get_client
client = get_client()
config_map = ConfigMap(
client=client,
name="app-settings",
namespace="default",
data={
# Application configuration
"app.properties": "app.name=MyApp\napp.version=2.0",
# Database configuration
"db.properties": "db.host=localhost\ndb.port=5432",
# Simple key-value pairs
"feature_flag": "enabled",
"timeout": "30"
}
)
config_map.create()
print("Multi-source ConfigMap created")
Using ConfigMap in a Pod (Volume Mount)
from ocp_resources.config_map import ConfigMap
from ocp_resources.pod import Pod
from ocp_resources.resource import get_client
client = get_client()
# Create ConfigMap
config_map = ConfigMap(
client=client,
name="app-config",
namespace="default",
data={
"config.json": '{"server": "localhost", "port": 8080}'
}
)
config_map.create()
# Create Pod that mounts the ConfigMap
pod = Pod(
client=client,
name="app-pod",
namespace="default",
containers=[{
"name": "app",
"image": "myapp:latest",
"volumeMounts": [{
"name": "config-volume",
"mountPath": "/etc/config"
}]
}],
volumes=[{
"name": "config-volume",
"configMap": {
"name": "app-config"
}
}]
)
pod.create()
print("Pod created with ConfigMap volume")
Using ConfigMap in a Pod (Environment Variables)
from ocp_resources.config_map import ConfigMap
from ocp_resources.pod import Pod
from ocp_resources.resource import get_client
client = get_client()
# Create ConfigMap
config_map = ConfigMap(
client=client,
name="env-config",
namespace="default",
data={
"DATABASE_URL": "postgres://db:5432/myapp",
"LOG_LEVEL": "debug"
}
)
config_map.create()
# Create Pod that uses ConfigMap as environment variables
pod = Pod(
client=client,
name="app-pod",
namespace="default",
containers=[{
"name": "app",
"image": "myapp:latest",
"envFrom": [{
"configMapRef": {
"name": "env-config"
}
}]
}]
)
pod.create()
print("Pod created with ConfigMap environment variables")
Updating a ConfigMap
from ocp_resources.config_map import ConfigMap
from ocp_resources.resource import get_client
client = get_client()
config_map = ConfigMap(
client=client,
name="app-config",
namespace="default"
)
# Update the data
config_map.update({
"data": {
"database_url": "postgres://newhost:5432/mydb",
"log_level": "debug",
"new_setting": "value"
}
})
print("ConfigMap updated")
Listing ConfigMaps
from ocp_resources.config_map import ConfigMap
from ocp_resources.resource import get_client
client = get_client()
# List all ConfigMaps in a namespace
for cm in ConfigMap.get(client=client, namespace="default"):
print(f"ConfigMap: {cm.name}")
if cm.instance.data:
print(f" Keys: {list(cm.instance.data.keys())}")
if cm.instance.binaryData:
print(f" Binary Keys: {list(cm.instance.binaryData.keys())}")
Using Context Manager
from ocp_resources.config_map import ConfigMap
from ocp_resources.resource import get_client
client = get_client()
with ConfigMap(
client=client,
name="temp-config",
namespace="default",
data={"temp_key": "temp_value"}
) as cm:
print(f"ConfigMap {cm.name} is available")
# ConfigMap is automatically deleted when exiting this block
Creating from YAML
from ocp_resources.config_map import ConfigMap
from ocp_resources.resource import get_client
client = get_client()
config_map = ConfigMap(
client=client,
yaml_file="/path/to/configmap.yaml"
)
config_map.create()
Best Practices
Size Limitations
ConfigMaps are stored in etcd and should not be used for large amounts of data. The recommended maximum size is 1 MiB per ConfigMap.
Immutability
For production environments, consider making ConfigMaps immutable to:
- Prevent accidental updates
- Improve performance (kubelet doesn’t need to watch for changes)
- Ensure consistency across pod restarts
Mounting as Files
When mounting ConfigMaps as volumes:
- Each key becomes a file in the mount directory
- File permissions default to 0644
- Updates to the ConfigMap are reflected in mounted volumes (after a sync period)
Environment Variables
When using ConfigMaps as environment variables:
- Updates to the ConfigMap do NOT automatically update pod environment variables
- Pods must be recreated to pick up new values
See Also
