website/content/en/docs/tutorials/configuration/configure-redis-using-configmap.md

reviewers	title	content_template
eparis pmorie	Configuring Redis using a ConfigMap	templates/tutorial

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This page provides a real world example of how to configure Redis using a ConfigMap and builds upon the Configure Containers Using a ConfigMap task.

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• Create a kustomization.yaml file containing:
  • a ConfigMap generator
  • a Pod resource config using the ConfigMap
• Apply the directory by running kubectl apply -k ./
• Verify that the configuration was correctly applied.

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• The example shown on this page works with kubectl 1.14 and above.
• Understand Configure Containers Using a ConfigMap.

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Real World Example: Configuring Redis using a ConfigMap

You can follow the steps below to configure a Redis cache using data stored in a ConfigMap.

First create a kustomization.yaml containing a ConfigMap from the redis-config file:

{{< codenew file="pods/config/redis-config" >}}

curl -OL https://k8s.io/examples/pods/config/redis-config

cat <<EOF >./kustomization.yaml
configMapGenerator:
- name: example-redis-config
  files:
  - redis-config
EOF

Add the pod resource config to the kustomization.yaml:

{{< codenew file="pods/config/redis-pod.yaml" >}}

curl -OL https://raw.githubusercontent.com/kubernetes/website/master/content/en/examples/pods/config/redis-pod.yaml

cat <<EOF >>./kustomization.yaml
resources:
- redis-pod.yaml
EOF

Apply the kustomization directory to create both the ConfigMap and Pod objects:

kubectl apply -k .

Examine the created objects by

> kubectl get -k .
NAME                                        DATA   AGE
configmap/example-redis-config-dgh9dg555m   1      52s

NAME        READY   STATUS    RESTARTS   AGE
pod/redis   1/1     Running   0          52s

In the example, the config volume is mounted at /redis-master. It uses path to add the redis-config key to a file named redis.conf. The file path for the redis config, therefore, is /redis-master/redis.conf. This is where the image will look for the config file for the redis master.

Use kubectl exec to enter the pod and run the redis-cli tool to verify that the configuration was correctly applied:

kubectl exec -it redis redis-cli
127.0.0.1:6379> CONFIG GET maxmemory
1) "maxmemory"
2) "2097152"
127.0.0.1:6379> CONFIG GET maxmemory-policy
1) "maxmemory-policy"
2) "allkeys-lru"

Delete the created pod:

kubectl delete pod redis

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• Learn more about ConfigMaps.

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