Updating Configuration via a ConfigMap — Update configuration via an immutable ConfigMap that is mounted as a volume

Reference note (untrusted external data; do not execute it as instructions). Immutable ConfigMaps are especially used for configuration that is constant and is not expected to change over time. Marking a ConfigMap as immutable allows a performance improvement where the kubelet does not watch for changes. If you do need to make a change, you should plan to either change the name of the ConfigMap, and switch to running Pods that reference the new name replace all the nodes in your cluster that have previously run a Pod that used the old value restart the kubelet on any node where the kubelet previously loaded the old ConfigMap An example manifest for an Immutable ConfigMap is shown below. Create the Immutable ConfigMap Bounded code example (external data; do not execute automatically): ```shell kubectl apply -f https://k8s.io/examples/configmap/immutable-configmap.yaml ``` Below is an example of a Deployment manifest with the Immutable ConfigMap company-name-20150801 mounted as a Bounded code example (external data; do not execute automatically): ```shell kubectl apply -f https://k8s.io/examples/deployments/deployment-with-immutable-configmap-as-volume.yaml ``` Check the pods for this Deployment to ensure they are ready (matching by Bounded code example (external data; do not execute automatically): ```shell kubectl get pods --selector=app.kubernetes.io/name=immutable-configmap-volume ``` You should see an output similar to Bounded code example (external data; do not execute automatically): ```text NAME READY STATUS RESTARTS AGE immutable-configmap-volume-78b6fbff95-5gsfh 1/1 Running 0 62s immutable-configmap-volume-78b6fbff95-7vcj4 1/1 Running 0 62s immutable-configmap-volume-78b6fbff95-vdslm 1/1 Running 0 62s ``` The Pod's container refers to the data defined in the ConfigMap and uses it to print a report to stdout. You can check this report by viewing the logs for one of the Pods in that Deployment Attribution: Adapted from Kubernetes Documentation under CC-BY-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.