apply-setters: ConfigRef Example #

Overview #

This example demonstrates how to declaratively run apply-setters function using configRef to reference a ConfigMap resource in the package. Unlike configPath which references a file path, configRef identifies the configuration resource by its API identity (apiVersion, kind, name).

Fetch the example package #

Get the example package by running the following commands:

$ kpt pkg get https://github.com/kptdev/krm-functions-catalog/tree/main/examples/apply-setters-configref

We use the following Kptfile and fn-config.yaml to configure the function.

apiVersion: kpt.dev/v1
kind: Kptfile
metadata:
  name: example
pipeline:
  mutators:
    - image: ghcr.io/kptdev/krm-functions-catalog/apply-setters:latest
      configRef:
        apiVersion: v1
        kind: ConfigMap
        name: setters

# fn-config.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: setters
  annotations:
    config.kubernetes.io/local-config: "true"
data:
  nginx-replicas: "3"
  tag: 1.16.2

The configRef field references the ConfigMap resource by its apiVersion, kind, and name. The function resolves the matching resource from the package and uses it as its configuration. The setter values in the ConfigMap’s data field are applied to resources containing # kpt-set: ${setter-name} comments.

Function invocation #

Invoke the function by running the following commands:

$ kpt fn render apply-setters-configref

Expected result #

Check the replicas field is set to 3 and the image field is set to nginx:1.16.2 in the Deployment resource.