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Config Maps

There are several ways to manage environment variables in Kubernetes. One of the most common ways is to use ConfigMaps. ConfigMaps allow us to decouple our configurations from our container images, which is important because we don't want to have to rebuild our images every time we want to change a configuration value.

In a Dockerfile we can set environment variables like this:

ENV PORT=3000

The trouble is, that means that everyone using that image will have to use port 3000. It also means that if we want to change the port, we have to rebuild the image.

Assignment

First, let's take a closer look at our crashing pod and try to figure out why it's crashing.

kubectl get pods

Copy the pod name and then get the logs:

kubectl logs <pod-name>

You should see that a specific environment variable is missing! Let's fix that.

Create a new file. Let's call it api-configmap.yaml. Add the following YAML to it:

apiVersion: v1
kind: ConfigMap
metadata/name: synergychat-api-configmap
data/API_PORT: "8080"

Next, apply the config map:

kubectl apply -f api-configmap.yaml

Now, we haven't yet connected the config map to our pod, so it should still be crashing. However, for now, let's just validate that the config map was created successfully:

kubectl get configmaps

Run:

kubectl proxy

Run and submit the CLI tests.