Search⌘ K
Home
Courses
A Practical Guide to Kubernetes

Converting ConfigMap Output to Environment Variables

Explore how to convert ConfigMap data into environment variables within Kubernetes pods. Understand the difference between specifying individual keys with env.valueFrom.configMapKeyRef and importing all keys using envFrom.configMapRef. This lesson helps you manage configuration more efficiently by choosing the appropriate method for injecting environment variables from ConfigMaps.

We'll cover the following...

Altering the perpetual process

All the examples we’ve seen so far differ only in the source. The destination is always the same. Whether ConfigMap is created from a file, a directory, literal values, or an environment file, it perpetually results in one or more files being injected into a container.

This time we’ll try something different. We’ll see how we can convert a ConfigMap to environment variables.

Looking into the first definition

Let’s look at a sample definition of alpine-env.yml file:

YAML
apiVersion: v1
kind: Pod
metadata:
  name: alpine-env
spec:
  containers:
  - name: alpine
    image: alpine
    command: ["sleep"]
    args: ["100000"]
    env:
    - name: something
      valueFrom:
        configMapKeyRef:
          name: my-config
          key: something
    - name: weather
      valueFrom:
        configMapKeyRef:
          name: my-config
          key: weather

Note: The major difference when compared with alpine.yml is that ...